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71 results on '"Dris Ihiawakrim"'

1. Ultrasonic chemical synthesis of zinc-manganese ferrites with improved magnetic properties

Author: Wafaa Azouzi, Ikram Boulahya, Jerome Robert, Ahmed Essyed, Abdelfattah Mahmoud, Ahmed Al Shami, Dris Ihiawakrim, Hicham Labrim, and Mohammed Benaissa
Subjects: Zn, Mn, Ferrites, Nanoparticles, Magnetization, Ultrasonic waves, Chemistry, QD1-999, Acoustics. Sound, QC221-246
Abstract: Zinc-Manganese spinel ferrites (Zn1-xMnxFe2O4) are nowadays very attractive magnetic materials for cancer diagnostic and therapy. With the help of intense ultrasonic waves, sonochemical synthesis method was used to prepare stoichiometric and chemically homogenous nanoparticles by varying the manganese content. The crystal structure along with the size and shape of the as-prepared nanoparticles were described using XRD, TEM and FT-IR techniques, while cations distribution was carefully investigated using XPS and Mössbauer spectroscopic techniques and supported with density functional theory calculations. The crystal structure study revealed the presence of a pure single cubic spinel phase, where the unit-cell and the size were observed to decrease as the manganese incorporation was increased with clear indication of cationic redistribution and degree of inversion variations. Due to the very small variation of the total energy between different configurations, the probability of formation of a mixed phase was found to be very high in such a way that the more mixed was the phase, the more stable it was. A relevant fact was the noticed quasi-systematic ionic exchange made possible by the very short reaction times and high energy offered by the ultrasonic waves. For manganese concentrations up to 60%, the systematic ionic process started by incorporating manganese ions into octahedral sites and pushing iron ions to migrate and replace those of zinc in tetrahedral sites. Such an ionic movement was of central importance for the improvement of the magnetic properties due to the establishment of super-exchange interactions. Such an ionic engineering should definitely open the way to promising applications in biomedical imaging.
Published: 2024
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2. Engineering siderophore production in Pseudomonas to improve asbestos weathering

Author: Marion Lemare, Hélène Puja, Sébastien R. David, Sébastien Mathieu, Dris Ihiawakrim, Valérie A. Geoffroy, and Coraline Rigouin
Subjects: Biotechnology, TP248.13-248.65
Abstract: Summary Iron plays a key role in microbial metabolism and bacteria have developed multiple siderophore‐driven mechanisms due to its poor bioavailability for organisms in the environment. Iron‐bearing minerals generally serve as a nutrient source to sustain bacterial growth after bioweathering. Siderophores are high‐affinity ferric iron chelators, of which the biosynthesis is tightly regulated by the presence of iron. Pyoverdine‐producing Pseudomonas have shown their ability to extract iron and magnesium from asbestos waste as nutrients. However, such bioweathering is rapidly limited due to repression of the pyoverdine pathway and the low bacterial requirement for iron. We developed a metabolically engineered strain of Pseudomonas aeruginosa for which pyoverdine production was no longer repressed by iron as a proof of concept. We compared siderophore‐promoted dissolution of flocking asbestos waste by this optimized strain to that by the wild‐type strain. Interestingly, pyoverdine production by the optimized strain was seven times higher in the presence of asbestos waste and the dissolution of magnesium and iron from the chrysotile fibres contained in flocking asbestos waste was significantly enhanced. This innovative mineral weathering process contributes to remove toxic iron from the asbestos fibres and may contribute to the development of an eco‐friendly method to manage asbestos waste.
Published: 2022
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3. Few-Layer Graphene from Mechanical Exfoliation of Graphite-Based Materials: Structure-Dependent Characteristics

Author: Azhar A. Pirzado, François Le Normand, Thierry Romero, Sandra Paszkiewicz, Vasiliki Papaefthimiou, Dris Ihiawakrim, and Izabela Janowska
Subjects: few-layer graphene, mechanical exfoliation, graphene nanocomposites, conductive layer, nuclear reaction analysis, Chemistry, QD1-999
Abstract: We present a high-scale method to produce few-layer graphene (FLG) based on the mechanical exfoliation of graphite and compare the obtained FLG with the one reported earlier arising from pencil lead ablation. Several elements were modified and improved in the new approach. The purification and the ablation set-up were simplified, and the morphology of the FLG was modified and improved in view of some applications. The morphology-dependent properties of FLGs, lead-FLG, and graphite-FLG as conductive layers and in nanocomposites were investigated. The newly obtained FLG had a higher aspect ratio (high lateral size vs thickness/higher 2D aspect), which is reflected by enhanced transparency–conductivity features of the layer (film) and elongation-at-break behavior of the polymer composites. On the contrary, the nanocomposite containing lead-FLG showed, for instance, excellent gas barrier properties due to the multi-step structure of the lead-FLG flakes. Such structure exhibited less 2D and more 3D character, which can be highly suitable for applications where the presence of active/reactive edges is beneficial, e.g., in catalysis or supercapacitors’ electrodes. Nuclear reaction analysis was employed to investigate the morphology of graphite-FLG film.
Published: 2019
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4. Enzymatically Active Polydopamine @ Alkaline Phosphatase Nanoparticles Produced by NaIO4 Oxidation of Dopamine

Author: Salima El Yakhlifi, Dris Ihiawakrim, Ovidiu Ersen, and Vincent Ball
Subjects: melanin-like nanoparticles, sodium periodate, enzymatic activity, layer-by-layer films, Technology
Abstract: Polydopamine (PDA) deposition, obtained from the oxidation of dopamine and other catecholamines, is a universal way to coat all known materials with a conformal coating which can subsequently be functionalized at will. The structural analogies between polydopamine and eumelanin, the black-brown pigment of the skin, were incited to produce stable polydopamine nanoparticles in solution, instead of amorphous precipitates obtained from the oxidation of dopamine. Herein, we demonstrate that size-controlled and colloidally stable PDA-based nanoparticles can be obtained in acidic conditions, where spontaneous auto-oxidation of dopamine is suppressed, using sodium periodate as the oxidant and a protein, like alkaline phosphatase (ALP), as a templating agent. The size of the PDA@ALP nanoparticles depends on the dopamine/enzyme ratio and the obtained particles display enzymatic activity of alkaline phosphatase, with an activity extending up to two weeks after particle synthesis. The PDA@ALP nanoparticles can be engineered in polyelectrolyte multilayered films to potentially design model biosensors.
Published: 2018
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5. Unravelling the Thermal Decomposition Parameters for The Synthesis of Anisotropic Iron Oxide Nanoparticles

Author: Geoffrey Cotin, Céline Kiefer, Francis Perton, Dris Ihiawakrim, Cristina Blanco-Andujar, Simona Moldovan, Christophe Lefevre, Ovidiu Ersen, Benoit Pichon, Damien Mertz, and Sylvie Bégin-Colin
Subjects: iron oxide nanoparticles, synthesis, shape control, thermal decomposition, precursor, Chemistry, QD1-999
Abstract: Iron oxide nanoparticles are widely used as a contrast agent in magnetic resonance imaging (MRI), and may be used as therapeutic agent for magnetic hyperthermia if they display in particular high magnetic anisotropy. Considering the effect of nanoparticles shape on anisotropy, a reproducible shape control of nanoparticles is a current synthesis challenge. By investigating reaction parameters, such as the iron precursor structure, its water content, but also the amount of the surfactant (sodium oleate) reported to control the shape, iron oxide nanoparticles with different shape and composition were obtained, in particular, iron oxide nanoplates. The effect of the surfactant coming from precursor was taking into account by using in house iron stearates bearing either two or three stearate chains and the negative effect of water on shape was confirmed by considering these precursors after their dehydration. Iron stearates with three chains in presence of a ratio sodium oleate/oleic acid 1:1 led mainly to nanocubes presenting a core-shell Fe1−xO@Fe3−xO4 composition. Nanocubes with straight faces were only obtained with dehydrated precursors. Meanwhile, iron stearates with two chains led preferentially to the formation of nanoplates with a ratio sodium oleate/oleic acid 4:1. The rarely reported flat shape of the plates was confirmed with 3D transmission electronic microscopy (TEM) tomography. The investigation of the synthesis mechanisms confirmed the major role of chelating ligand and of the heating rate to drive the cubic shape of nanoparticles and showed that the nanoplate formation would depend mainly on the nucleation step and possibly on the presence of a given ratio of oleic acid and chelating ligand (oleate and/or stearate).
Published: 2018
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6. Hierarchical superparamagnetic metal–organic framework nanovectors as anti-inflammatory nanomedicines

Author: Heng Zhao, Saad Sene, Angelika M. Mielcarek, Sylvain Miraux, Nicolas Menguy, Dris Ihiawakrim, Ovidiu Ersen, Christine Péchoux, Nathalie Guillou, Joseph Scola, Jean-Marc Grenèche, Farid Nouar, Simona Mura, Florent Carn, Florence Gazeau, Eddy Dumas, Christian Serre, Nathalie Steunou, Institut des Matériaux Poreux de Paris (IMAP ), Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre de résonance magnétique des systèmes biologiques (CRMSB), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, Génétique Animale et Biologie Intégrative (GABI), AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Groupe d'Etude de la Matière Condensée (GEMAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Institut des Molécules et Matériaux du Mans (IMMM), Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Galien Paris-Saclay (IGPS), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Matière et Systèmes Complexes (MSC), and Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Biomedical Engineering, [CHIM]Chemical Sciences, General Materials Science, General Chemistry, General Medicine
Abstract: International audience; Among a plethora of drug nanocarriers, biocompatible nanoscale metal-organic frameworks (nanoMOFs) with a large surface area and an amphiphilic internal microenvironment have emerged as promising drug delivery platforms, mainly for cancer therapy. However, their application in biomedicine still suffers from shortcomings such as a limited chemical and/or colloidal stability and/or toxicity. Here, we report the design of a hierarchically porous nano-object (denoted as USPIO@MIL) combining a benchmark nanoMOF (that is, MIL-100(Fe)) and ultra-small superparamagnetic iron oxide (USPIO) nanoparticles (that is, maghemite) that is synthesized through a one-pot, cost-effective and environmentally friendly protocol. The synergistic coupling of the physico-chemical and functional properties of both nanoparticles confers to these nano-objects valuable features such as high colloidal stability, high biodegradability, low toxicity, high drug loading capacity as well as stimuli-responsive drug release and superparamagnetic properties. This bimodal MIL-100(Fe)/maghemite nanocarrier once loaded with anti-tumoral and anti-inflammatory drugs (doxorubicin and methotrexate) shows high anti-inflammatory and anti-tumoral activities. In addition, the USPIO@MIL nano-object exhibits excellent relaxometric properties and its applicability as an efficient contrast agent for magnetic resonance imaging is herein demonstrated. This highlights the high potential of the maghemite@MOF composite integrating the functions of imaging and therapy as a theranostic anti-inflammatory formulation.
Published: 2023
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7. Live Visualization of the Nucleation and Growth of Needle-Like Hydroxyapatite Crystals in Solution by In Situ TEM

Author: Gisele M. L. Dalmônico, Dris Ihiawakrim, Nathaly Ortiz, Amaro Gomes Barreto Junior, Caio Felippe Curitiba Marcellos, Marcos Farina, Ovidiu Ersen, and Andre L. Rossi
Subjects: General Materials Science, General Chemistry, Condensed Matter Physics
Published: 2022
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8. Applications of Biological Magnetic Nanoparticles in Nanobiotechnology

Author: Juliana G. Ferreira, Vinavadini Ramnarain, Igor Taveira, Júlia de Castro, Rogerio Presciliano, Beatriz A. Vessalli, Dris Ihiawakrim, Ovidiu Ersen, and Fernanda Abreu
Published: 2023
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9. Intrinsic photoanode band engineering: enhanced solar water splitting efficiency mediated by surface segregation in Ti-doped hematite nanorods

Author: Stefan Stanescu, Théo Alun, Yannick J. Dappe, Dris Ihiawakrim, Ovidiu Ersen, and Dana Stanescu
Abstract: Band engineering is thoroughly employed nowadays targeting technologically scalable photoanodes for solar water splitting applications. Most often complex and costly recipes are necessary, for average performances. Here we report very simple photoanode growth and thermal annealing, with effective band engineering results. Strongly enhanced photocurrent, of more than 200 %, is measured for Ti-doped hematite nanorods grown from aqueous solutions and annealed under Nitrogen atmosphere, compared to air annealed ones. Oxidized surface states and increased density of charge carriers are found responsible for the enhanced photoelectrochemical activity, as shown by electrochemical impedance spectroscopy and synchrotron X-rays spectromicroscopies. They are found related to oxygen vacancies, acting as n-dopants, and the formation of pseudo-brookite clusters by surface Ti segregation. Spectro-ptychography is used for the first time at Ti L3 absorption edge to isolate Ti chemical coordination arising from pseudo-brookite clusters contribution. Correlated with electron microscopy investigation and Density Functional Theory (DFT) calculations, our data unambiguously prove the origin of the enhanced photoelectrochemical activity of N2-annealed Ti-doped hematite nanorods. Finally, we present here a handy and cheap surface engineering method beyond the known oxygen vacancy doping, allowing a net gain in the photoelectrochemical activity for the hematite-based photoanodes.
Published: 2023
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10. 3D multiscale analysis of the hierarchical porosity in Coscinodiscus sp. diatoms using a combination of tomographic techniques

Author: Othmane Darouich, Walid Baaziz, Dris Ihiawakrim, Charles Hirlimann, Danièle Spehner, Patrick Schultz, Hedwige Poncet, Virgile Rouchon, Sana Labidi, Corinne Petit, Pierre Levitz, Ovidiu Ersen, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), IFP Energies nouvelles (IFPEN), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), PHysicochimie des Electrolytes et Nanosystèmes InterfaciauX (PHENIX), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), APC 1902 €, ANR-10-IDEX-0002,UNISTRA,Par-delà les frontières, l'Université de Strasbourg(2010), ANR-20-SFRI-0002,GP-DS,Graduate Programs pour les études doctorales(2020), ANR-17-EURE-0024,QMAT,Quantum Science and Nanomaterials(2017), Belli, Catherine, Initiative d'excellence - Par-delà les frontières, l'Université de Strasbourg - - UNISTRA2010 - ANR-10-IDEX-0002 - IDEX - VALID, Graduate Programs pour les études doctorales - - GP-DS2020 - ANR-20-SFRI-0002 - SFRI - VALID, and Quantum Science and Nanomaterials - - QMAT2017 - ANR-17-EURE-0024 - EURE - VALID
Subjects: [SDV] Life Sciences [q-bio], [SDE] Environmental Sciences, [SDV]Life Sciences [q-bio], [SDE]Environmental Sciences, [CHIM] Chemical Sciences, General Engineering, [CHIM]Chemical Sciences, General Materials Science, Bioengineering, General Chemistry, Atomic and Molecular Physics, and Optics
Abstract: International audience; A full 3D analysis of the hierarchical porosity in Coscinodiscus sp. diatom structures was carried out by using a multiscale approach that combines three advanced volumetric imaging techniques with resolutions and fields of view covering all the porous characteristics of such complex architectures: electron tomography, "slice and view" approach that uses a dual-beam microscope (FIB-SEM), and array tomography consisting of serial imaging of ultrathin specimen sections. This multiscale approach allowed the whole porosity network to be quantified and provided an unprecedented structural insight into these natural nanostructured materials with internal organization ranging from micrometer to nanometer. The analysed species is made of several nested layers with different pore sizes, shapes and connectivities and characterized by the presence of interconnected pores structured in various ways. The first evidence of the presence of a nanometric porosity made of ellipsoidal pores in the siliceous diatom frustules is also provided.
Published: 2022
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11. The influence of <scp>l</scp>-aspartic acid on calcium carbonate nucleation and growth revealed by in situ liquid phase TEM

Author: Mariana M. Longuinho, Vinavadini Ramnarain, Nathaly Ortiz Peña, Dris Ihiawakrim, Rubén Soria-Martínez, Marcos Farina, Ovidiu Ersen, and André L. Rossi
Subjects: General Materials Science, General Chemistry, Condensed Matter Physics
Abstract: The l-Asp has a modulator function during CaCO3 crystallization by interaction with free calcium through coordinated bonds, forming vesicle-like structures during interaction CaCO3 nuclei.
Published: 2022
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12. TiO2-supported Co catalysts for the hydrogenation of γ-valerolactone to 2-methyltetrahydrofuran: influence of the support

Author: Emilia Soszka, Marcin Jędrzejczyk, Christophe Lefèvre, Dris Ihiawakrim, Nicolas Keller, Agnieszka M. Ruppert, Łódź University of Technology, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), and Keller, Nicolas
Subjects: [CHIM] Chemical Sciences, [CHIM]Chemical Sciences, [CHIM.CATA] Chemical Sciences/Catalysis, [CHIM.CATA]Chemical Sciences/Catalysis, Catalysis
Abstract: International audience; 2-Methyltetrahydrofuran (MTHF) is considered as one of the most promising green fuel alternatives that could be obtained from renewable lignocellulosic biomass through the catalytic hydrogenation of the γ-valerolactone (GVL) platform molecule. In the current work, we report on the ability of earth-abundant non-noble metal Co catalysts supported on TiO2 to be used efficiently for the synthesis of MTHF. The activity of TiO2-supported Co catalysts in the hydrogenation of GVL to 2-MTHF was investigated, and several key factors with significant influence on the reaction have been identified and discussed. Among them, we pointed out the crucial role of the titania support as a versatile tool able to drive the properties of the supported metallic cobalt nanoparticles and consequently the activity of the catalysts. In addition to the necessary catalyst acidity, we showed that the catalyst performances were related to the Co particle size and to the metal–support interaction, both properties being highly dependent on the composition of the titania support. We demonstrated the beneficial co-presence of both anatase and rutile crystalline phases within the TiO2 support, and we proposed that the nature of the crystalline phase not only influences the Co particle size and the catalyst acidity but also allows tuning the SMSI effect for achieving optimum performances in 2-MTHF synthesis.
Published: 2022
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13. Monitoring of CaCO

Author: Vinavadini, Ramnarain, Tristan, Georges, Nathaly, Ortiz Peña, Dris, Ihiawakrim, Mariana, Longuinho, Hervé, Bulou, Christel, Gervais, Clément, Sanchez, Thierry, Azaïs, and Ovidiu, Ersen
Subjects: Aspartic Acid, Magnetic Resonance Spectroscopy, Microscopy, Electron, Transmission, Carbonates, Calcium Carbonate
Abstract: Calcium carbonate (CaCO
Published: 2022

14. In situ liquid transmission electron microscopy reveals self-assembly-driven nucleation in radiolytic synthesis of iron oxide nanoparticles in organic media

Author: Nathaly Ortiz Peña, Dris Ihiawakrim, Sorina Creţu, Geoffrey Cotin, Céline Kiefer, Sylvie Begin-Colin, Clément Sanchez, David Portehault, Ovidiu Ersen, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Novel Advanced Nano-Objects (LCMCP-NANO), Matériaux Hybrides et Nanomatériaux (LCMCP-MHN), Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Portehault, David
Subjects: [CHIM.INOR] Chemical Sciences/Inorganic chemistry, [CHIM.MATE] Chemical Sciences/Material chemistry, Aucun, General Materials Science, [CHIM.MATE]Chemical Sciences/Material chemistry, [CHIM.INOR]Chemical Sciences/Inorganic chemistry
Abstract: International audience; We have investigated the early stages of formation of iron oxide nanoparticles from iron stearate precursors in the presence of sodium stearate in an organic solvent by in situ liquid phase transmission electron microscopy (IL-TEM). Before nucleation, we have evidenced the spontaneous formation of vesicular assemblies made of iron polycation-based precursors sandwiched between stearate layers. Nucleation of iron oxide nanoparticles occurs within the walls of the vesicles, which subsequently collapse upon consumption of the iron precursors and growth of the nanoparticles. We then evidenced that fine control of the electron dose, and therefore of the local concentration of reactive iron species in the vicinity of the nuclei, enables controlling crystal growth and selecting the morphology of the resulting iron oxide nanoparticles. Such direct observation of the nucleation process templated by vesicular assemblies in a hydrophobic organic solvent sheds new light on the formation process of metal oxide nanoparticles and therefore opens ways for the synthesis of inorganic colloidal systems with tunable shape and size.
Published: 2022
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15. Gold labelling of a green fluorescent protein (GFP)-tag inside cells using recombinant nanobodies conjugated to 2.4 nm thiolate-coated gold nanoparticles

Author: Dris Ihiawakrim, Nadja Groysbeck, Anne Marie Haeberlé, Mariel Donzeau, Mounib Bahri, Ovidiu Ersen, Audrey Stoessel, Patrick Schultz, Guy Zuber, Stéphane Ory, Danièle Spehner, Institut des Neurosciences Cellulaires et Intégratives (INCI), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), schultz, patrick, Biotechnologie et signalisation cellulaire (BSC), Université de Strasbourg (UNISTRA)-Institut de recherche de l'Ecole de biotechnologie de Strasbourg (IREBS)-Centre National de la Recherche Scientifique (CNRS), Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDV.BIO]Life Sciences [q-bio]/Biotechnology, [SDV]Life Sciences [q-bio], Bioengineering, Peptide, 02 engineering and technology, Conjugated system, Green fluorescent protein, law.invention, 03 medical and health sciences, law, General Materials Science, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, Chemistry, General Engineering, Sciences du Vivant [q-bio]/Biotechnologies, General Chemistry, Immunogold labelling, 021001 nanoscience & nanotechnology, Heterotetramer, Atomic and Molecular Physics, and Optics, [SDV] Life Sciences [q-bio], Colloidal gold, Recombinant DNA, PEGylation, Biophysics, 0210 nano-technology
Abstract: The advances in the microscopy technology have prompted efforts to improve the reagents required to recognize specific molecules within the intracellular environment. For high-resolution electron microscopy, conjugation of selective binders originating from the immune response arsenal to gold nanoparticles (AuNPs) as contrasting agents is the method of choice to obtain labeling tools. However, conjugation of the minimal sized 15 kDa nanobody (Nb) to AuNP remains challenging in comparison to the conjugation of 150 kDa IgG to AuNP. In here, effective Nb-AuNP assemblies are built using the selective and almost irreversible non-covalent associations between two peptide sequences deriving from a p53 heterotetramer domain variant. The 15 kDa GFP-binding Nb is fused to one dimerizing motif to obtain a recombinant Nb dimer with improved avidity for GFP while the other complementing dimerizing motif is equipped with thiols and grafted to a 2.4 nm substituted thiobenzoate-coordinated AuNP via thiolate exchange. After pegylation, the modified AuNPs are able to non- covalently anchor Nb dimers and the subsequent complexes demonstrate the ability to immunogold label GFP-protein fusions within various subcellular locations. These tools open an avenue for precise localization of targets at high resolution by electron microscopy.
Published: 2021
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16. A compact photoreactor for automated H2 photoproduction: Revisiting the (Pd, Pt, Au)/TiO2 (P25) Schottky junctions

Author: Pablo Jimenéz-Calvo, Mario J. Muñoz-Batista, Mark Isaacs, Vinavadini Ramnarain, Dris Ihiawakrim, Xiaoyan Li, Miguel Ángel Muñoz-Márquez, Gilberto Teobaldi, Mathieu Kociak, Erwan Paineau, Laboratoire de Physique des Solides (LPS), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Universidad de Granada = University of Granada (UGR), HarwellXPS EPSRC, Department of Chemistry [University College of London], University College of London [London] (UCL), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), School of Science and Technology [Camerino], Università degli Studi di Camerino = University of Camerino (UNICAM), Scientific Computing Department, STFC, University of Southampton, ANR-18-CE09-0001,C3PO,Confinement et photocatalyse dans des nanotubes polarisés(2018), ANR-10-EQPX-0050,TEMPOS,Microscopie electronique en transmission sur le plateau Palaiseau Orsay Saclay(2010), and European Project: 101068996,LASERION
Subjects: photocatalytic hydrogen, [CHIM.GENI]Chemical Sciences/Chemical engineering, General Chemical Engineering, Photonic profile, co-catalysts, Photoreactor, Environmental Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, General Chemistry, Schottky junctions, Industrial and Manufacturing Engineering
Abstract: International audience; The configuration and geometry of chemical reactors underpins the accuracy of performance evaluation for photocatalytic materials and, accordingly, the development and validation of thermodynamic and kinetic model reactions. The lack of accurate photonic, mass, and heat transport profiles for photochemical reactors hinder standardization, scale-up, and ultimately comparison between different experiments. This work proposes two contributions at the interface between engineering of chemical process and materials science: (A) an automated compact stainless-steel photoreactor with 40 cm3 and 65 cm2 of volume and area, respectively, for hydrogen photoproduction as a model reaction and (B) the synthesis, characterization, and performance of TiO2 Schottky junctions, using Pd, Pt, or Au nanoparticles (ca. 0.5, 1, 2wt.% loadings each) to validate the operation of the reactor. A photonic profile methodology is implemented to the studied reactor to obtain the local light absorption profile, opening up for evaluation of the local quantum yield calculation for the selected materials. A combination of transmission electron microscopy, (X-ray/ultraviolet) photoelectron/electron, energy loss/infrared spectroscopies, X-ray scattering, inductively coupled plasma atomic emission spectroscopy, and ultraviolet-visible spectrophotometry is employed to determine the distinctive surface and bulk properties to build structure-function correlations. The (Pd, Pt, Au)/TiO2 Schottky junction exhibits H2 production rates slightly higher than previous studies, with quantum yields almost 2-fold higher than reported values. These results, demonstrate that the proposed novel geometry of the photoreactor improves the photonic, heat, and mass profiles. An in-depth analysis of the Au plasmon was investigated coupling electron energy loss spectroscopy, UV-vis, and transmission electron microscope, resulting in insightful information about the Au NP mode at the TiO2 interface.
Published: 2023
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17. Solid‐State Field‐Assisted Ion Exchange (Ag → Na) in Soda–Lime Float Glass: Tin Versus Air Side

Author: Mattia Biesuz, Gino Mariotto, Michele Cassetta, Ovidiu Ersen, Dris Ihiawakrim, Petr Haušild, Paolo Giopato, Alessandro Martucci, Mauro Bortolotti, Vincenzo M. Sglavo, and Gian D. Sorarù
Subjects: silver nanoparticles, General Materials Science, ion exchange, electric field, glasses, Condensed Matter Physics
Published: 2023
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18. A detailed investigation of the core@shell structure of exchanged coupled magnetic nanoparticles after performing solvent annealing

Author: Kevin Sartori, Dris Ihiawakrim, Christophe Lefèvre, Solenn Reguer, Cristian Mocuta, Sylvie Bégin-Colin, Fadi Choueikani, Benoit P. Pichon, Lefevre, Christophe, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), and Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.)
Subjects: [CHIM.MATE] Chemical Sciences/Material chemistry, Chemistry (miscellaneous), General Materials Science, [CHIM.MATE]Chemical Sciences/Material chemistry
Abstract: International audience; Thanks to important advances in synthesis techniques, a wide collection of bimagnetic core-shell nanoparticles with tunable properties was reported in the literature. Such nanoparticles may combine two phases with different intrinsic magnetic properties (magnetization, anisotropy, coercive field, etc.). Core-shell structures with large interfaces usually favor efficient exchange coupling between both phases that may result in the enhancement of the effective magnetic anisotropy energy and of the coercive field. In this context, the chemical composition and the crystal structure of the core/shell interface in nanoparticles are crucial parameters to modulate efficiently their magnetic properties. Here, we report on the solvent mediated thermal annealing of Fe 3Àd O 4 @CoO nanoparticles in a high boiling point solvent. The structure of nanoparticles was investigated before and after thermal annealing by advanced characterization techniques such as high resolution transmission electron microscopy (HR-TEM), X-ray absorption spectroscopy (XAS), X-ray magnetic circular dichroism (XMCD) and diffraction anomalous near edge structure (DANES). The combination of DANES and XAS/XMCD allowed studying the cationic distribution in spinel and wu ¨stite crystal structures as a function of site occupancy and oxidation state. To the best of our knowledge, it is the first time that DANES is performed to quantitatively investigate the chemical composition of biphasic metal oxide nanoparticles. Hence, we have investigated precisely the chemical composition of the spinel phase and that of the wu ¨stite phase. Besides the partial solubilisation of the CoO shell observed by HR-TEM, thermal annealing favors the formation of a thicker intermediate Co-doped ferrite layer at the spinel/wu ¨stite interface. Such significant modifications of the core@shell structure markedly influence interfacial coupling phenomena between the core and the shell, hence offering wide perspectives towards nanoparticles with tunable magnetic properties for a variety of applications.
Published: 2022
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19. Mercury cyclic porosimetry: Measuring pore-size distributions corrected for both pore-space accessivity and contact-angle hysteresis

Author: Zongyu Gu, Martin Z. Bazant, Ovidiu Ersen, Dris Ihiawakrim, Pierre Levitz, Goulet Remi J, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, and Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)
Subjects: Materials science, [PHYS.PHYS]Physics [physics]/Physics [physics], Capillary action, Multiphase flow, Continuum (design consultancy), Thermodynamics, 02 engineering and technology, Porosimetry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Biomaterials, Contact angle, Hysteresis, Colloid and Surface Chemistry, Distribution (mathematics), 0210 nano-technology, Porous medium
Abstract: We propose a set of simple formulae for interpreting “mercury cyclic porosimetry” measurements where multiple intrusion–extrusion cycles are carried out. By employing two parameters α ∈ [ 0 , 1 ] and κ ∈ [ 0 , 1 ] , our theory quantitatively breaks down any hysteresis observed in cyclic porosimetry data into contributions due to connectivity effects and contact-angle hysteresis, respectively. In particular, the parameter α , called “pore-space accessivity”, characterizes any serial connectivity between different-size pores. It has long been recognized that the standard method for determining the pore-size distribution (PSD) from mercury intrusion data based on the capillary bundle assumption overestimates the fraction of smaller pores; that corresponds to the α → 1 limit of our model. In contrast, for materials with α 1 , our theory predicts a broadened PSD shifted toward larger radii, thus representing a simple way of rectifying PSDs for connectivity effects. The proposed model also establishes mercury cyclic porosimetry as a standard experimental procedure for measuring α , which can then be used in continuum models of porous media where connectivity effects play a significant role, such as in multiphase flow.
Published: 2021
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20. The effect of basic pH on the elaboration of ZnFe2O4 nanoparticles by co-precipitation method: Structural, magnetic and hyperthermia characterization

Author: M. Benaissa, Omar Mounkachi, Walid Baaziz, Dris Ihiawakrim, Ovidiu Ersen, M.A. Ait Kerroum, M. Hamedoun, Abdelilah Benyoussef, Cristian Iacovita, A. Essyed, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010302 applied physics, Materials science, Spinel, Analytical chemistry, Nanoparticle, 02 engineering and technology, engineering.material, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Magnetostatics, 01 natural sciences, Electronic, Optical and Magnetic Materials, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Magnetization, Magnetic hyperthermia, Transmission electron microscopy, 0103 physical sciences, engineering, Magnetic nanoparticles, 0210 nano-technology, Superparamagnetism
Abstract: The present study reports on the synthesis and characterization of zinc iron oxide ZnFe2O4 magnetic nanoparticles (MNPs) using the co-precipitation method. Particular attention has been paid to study the influence of the pH in the range between 9 and 12 on both structural and magnetic properties of the MNPs. X-ray diffraction analysis shows the presence of a single phase of partially invers cubic spinel ferrites ZnFe2O4. Transmission Electron Microscopy (TEM) analysis shows the formation of highly crystalline MNPs and a change of shape from a polyhedral shape at pH 9 to a spherical-like shape for a pH 12. The MNPs mean-size increases from 19 to 33 nm with the increase of pH value. The ZnFe2O4 MNPs are superparamagnetic at room temperature displaying a magnetization of 12 emu/g at the maximum applied static magnetic field. The heating efficiency of spherical zinc ferrites MNPs was evaluated for hyperthermia application and displays a linear increment of the specific absorption rate (SAR) up to 125 (W/gFe) under an alternating magnetic field ranging from 5 to 65 kA/m and operating at a frequency of 355 kHz.
Published: 2019
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21. New Insights into the Growth Mechanism of WO3 Gels by In-situ Liquid-Phase TEM and Time-Resolved DLS

Author: Charles Sidhoum, Mateusz Odziomek, Dris Ihiawakrim, Doru Constantin, François Schossler, Clément Sanchez, and Ovidiu Ersen
Subjects: Instrumentation
Published: 2021
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22. Versatile template-directed synthesis of gold nanocages with a predefined number of windows

Author: Fabrice Vallée, Ovidiu Ersen, Etienne Duguet, Fabien Vialla, Anna Lombardi, Serge Ravaine, Alexandra Madeira, Cyril Chomette, Aurélien Crut, Ileana Florea, Jérôme Majimel, Dris Ihiawakrim, Adeline Perro, Etienne Pertreux, Anthony Désert, Céline Hubert, Natalia Del Fatti, Paolo Maioli, Mona Tréguer-Delapierre, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Paul Pascal (CRPP), Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), FemtoNanoOptics (FemtoNanoOptics), Institut Lumière Matière [Villeurbanne] (ILM), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, STEM-EDX analyses were performed at the Plateforme Aquitaine de Caractérisation des Matériaux and Bordeaux Imaging Center of the University of Bordeaux. This work was supported by the Conseil Régional d’Aquitaine, the Agence Nationale de la Recherche (grant ANR-07-BLAN-0271 and ANR-BLAN-SIMI10-LS-100617-15-01), and the LabEx AMADEus (ANR-10-LABX-42) in the framework of IdEx Bordeaux (ANR-10-IDEX-03-02), i.e. the Investissements d’Avenir programme of the French government. The authors acknowledge Dr Véronique Many for some parallel experiments, Dr Laurent Adumeau and Dr Stéphane Mornet for helpful discussion, and Dr Yohan Grand for SEM experiments performed at ITODYS laboratory (UMR 7086, Univ. Paris Diderot)., ANR-07-BLAN-0271,Towards colloïd,Towards Colloidal Molecules and Functional Materials(2007), ANR-10-LABX-0042,AMADEus,Advanced Materials by Design(2010), ANR-10-IDEX-0003,IDEX BORDEAUX,Initiative d'excellence de l'Université de Bordeaux(2010), ANR-10-BLAN-1008,UNIT3D,Nanoparticule hybride unique: synthèse et corrélation entre sa réponse optique et sa caractérisation par microscopie électronique analytique en 3D.(2010), Toulin, Stéphane, Blanc - Towards Colloidal Molecules and Functional Materials - - Towards colloïd2007 - ANR-07-BLAN-0271 - BLANC - VALID, Advanced Materials by Design - - AMADEus2010 - ANR-10-LABX-0042 - LABX - VALID, Initiative d'excellence de l'Université de Bordeaux - - IDEX BORDEAUX2010 - ANR-10-IDEX-0003 - IDEX - VALID, BLANC - Nanoparticule hybride unique: synthèse et corrélation entre sa réponse optique et sa caractérisation par microscopie électronique analytique en 3D. - - UNIT3D2010 - ANR-10-BLAN-1008 - BLANC - VALID, Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: [CHIM.MATE] Chemical Sciences/Material chemistry, Nanostructure, Fabrication, Materials science, Nanotechnology, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Spatial modulation, 0104 chemical sciences, chemistry.chemical_compound, Template, Nanocages, chemistry, Etching, Particle, General Materials Science, Polystyrene, 0210 nano-technology
Abstract: International audience; Highly symmetrical gold nanocages can be produced with a controllable number of circular windows of either 2, 3, 4, 6 or 12 via an original fabrication route. The synthetic pathway includes three main stages: the synthesis of silica/polystyrene multipod templates, the regioselective seeded growth of a gold shell on the unmasked part of the silica surface and the development of gold nanocages by dissolving/etching the templates. Electron microscopy and tomography provide evidence of the symmetrical features of the as-obtained nanostructures. The optical properties of nanocages with 4 and 12 windows were measured at the single particle level by spatial modulation spectroscopy and correlated with numerical simulations based on finite-element modeling. The new multi-step synthesis approach reported here also allows the synthesis of rattle-like nanostructures through filling of the nanocages with a guest nano-object. With the potential to adjust the chemical composition, size and geometry of both the guest particle and the host cage, it opens new routes towards the fabrication of hollow nanostructures of high interest for a variety of applications including sensing devices, catalytic reactors and biomedicine. New concepts We demonstrate a new concept for making hollow nanoscale structures which are central to the advances in many current and emerging areas of technology. Nanocages are hollow and porous nanostructures. The ones made of metal are needed for optics, catalysis, biomedicine, and sensing. But, they are difficult to make. In particular, it is difficult to yield precise nanoscale control of the porosity as well as the composition. We address this challenge by combining inorganic colloidal synthesis and metal deposition on biphasic sacrificial templates. The single-particle spectroscopy and simulation confirm that our approach affords tight control over the morphology and porosity at the nanoscale. Previous approaches to making metal nanocages rely on galvanic replacement reactions and siteselective deposition. They offer control over morphology, but limited control over composition, porosity and scaleup. Our approach provides a simple and general strategy to circumvent these issues. It can be applied to a wide range of materials, and with further developement to any nanorattle-like nanostructures.
Published: 2021
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23. Correlative Microscopy Insight on Electrodeposited Ultrathin Graphite Oxide Films

Author: Nathaly Ortiz Peña, Stefan Stanescu, Dris Ihiawakrim, David Portehault, Ovidiu Ersen, Mircea V. Rastei, Clément Sanchez, Vincent Ball, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Faculté de chirurgie dentaire - Strasbourg, Université de Strasbourg (UNISTRA), Chaire Chimie des matériaux hybrides, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), and Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Graphite oxide, 02 engineering and technology, Electronic structure, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrochemistry, 01 natural sciences, 0104 chemical sciences, Electrochemical cell, chemistry.chemical_compound, Chemical engineering, chemistry, Transmission electron microscopy, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Microscopy, General Materials Science, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, 0210 nano-technology, Spectroscopy, ComputingMilieux_MISCELLANEOUS, Nanosheet
Abstract: Here, we present a correlative microscopic analysis of electrodeposited films from catechol solutions in aqueous electrolytes. The films were prepared in a miniaturized electrochemical cell and were analyzed by identical location transmission electron microscopy, scanning transmission X-ray microscopy, and atomic force microscopy. Thanks to this combined approach, we have shown that the electrodeposited films are constituted of ultrathin graphite oxide nanosheets. Detailed information about the electronic structure of the films was obtained by X-ray absorption near edge structure spectroscopy. These results show the large potential of soft electrochemical conditions for the bottom-up production of ultrathin graphite oxide nanosheet films via a one-pot green chemistry approach from simple organic building blocks.
Published: 2020
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24. Quantitative Analysis of the Specific Absorption Rate Dependence on the Magnetic Field Strength in ZnxFe3−xO4 Nanoparticles

Author: M. Benaissa, Dris Ihiawakrim, Constantin Mihai Lucaciu, Walid Baaziz, Cristian Iacovita, Guillaume Rogez, Ovidiu Ersen, Mohamed Alae Ait Kerroum, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Iuliu Hatieganu University of Medicine & Pharmacy, Laboratoire de Matière Condensée et Sciences Interdisciplinaires (LaMCScI), University of Mohammed V, Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Université Mohammed V de Rabat [Agdal] (UM5), and Rogez, Guillaume
Subjects: Neel relaxation time, Analytical chemistry, Aucun, Metal Nanoparticles, 02 engineering and technology, 01 natural sciences, lcsh:Chemistry, X-Ray Diffraction, Spectroscopy, Fourier Transform Infrared, Saturation (magnetic), lcsh:QH301-705.5, Spectroscopy, Relaxation (NMR), Temperature, General Medicine, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 3. Good health, Computer Science Applications, Magnetic field, Zinc, specific absorption rate, Linear Response Theory, 0210 nano-technology, Superparamagnetism, Materials science, 010402 general chemistry, zinc doped iron oxide magnetic nanoparticles, Catalysis, Article, Citric Acid, Inorganic Chemistry, Magnetization, Microscopy, Electron, Transmission, magnetic hyperthermia, Physical and Theoretical Chemistry, Molecular Biology, [CHIM.MATE] Chemical Sciences/Material chemistry, saturation of SAR, co-precipitation method, Organic Chemistry, Spectrometry, X-Ray Emission, Hyperthermia, Induced, Magnetostatics, Ferrosoferric Oxide, 0104 chemical sciences, Magnetic hyperthermia, Magnetic Fields, lcsh:Biology (General), lcsh:QD1-999, Brown relaxation time, Magnetic nanoparticles, human activities
Abstract: Superparamagnetic ZnxFe3&minus, xO4 magnetic nanoparticles (0 &le, x &lt, 0.5) with spherical shapes of 16 nm average diameter and different zinc doping level have been successfully synthesized by co-precipitation method. The homogeneous zinc substitution of iron cations into the magnetite crystalline structure has led to an increase in the saturation magnetization of nanoparticles up to 120 Am2/kg for x ~ 0.3. The specific absorption rate (SAR) values increased considerably when x is varied between 0 and 0.3 and then decreased for x ~ 0.5. The SAR values are reduced upon the immobilization of the nanoparticles in a solid matrix being significantly increased by a pre-alignment step in a uniform static magnetic field before immobilization. The SAR values displayed a quadratic dependence on the alternating magnetic field amplitude (H) up to 35 kA/m. Above this value, a clear saturation effect of SAR was observed that was successfully described qualitatively and quantitatively by considering the non-linear field&rsquo, s effects and the magnetic field dependence of both Brown and Neel relaxation times. The Neel relaxation time depends more steeply on H as compared with the Brown relaxation time, and the magnetization relaxation might be dominated by the Neel mechanism, even for nanoparticles with large diameter.
Published: 2020
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25. Characterizing surface states in hematite nanorod photoanodes, both beneficial and detrimental to solar water splitting efficiency

Author: Dris Ihiawakrim, Adam P. Hitchcock, Stefan Stanescu, D. Stanescu, Victoria Villard, S. G. Chiuzbaian, Jocelyne Leroy, Cristian Mocuta, Mekan Piriyev, Adrien Besson, Ovidiu Ersen, Laboratoire Nano-Magnétisme et Oxydes (LNO), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), McMaster University Hamilton - Department of Chemistry & Chemical Biology, Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique
Subjects: Diffraction, Nanostructure, Materials science, Renewable Energy, Sustainability and the Environment, 02 engineering and technology, General Chemistry, Electronic structure, [CHIM.MATE]Chemical Sciences/Material chemistry, Hematite, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, X-ray photoelectron spectroscopy, Chemical engineering, visual_art, Microscopy, visual_art.visual_art_medium, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Materials Science, Nanorod, 0210 nano-technology, Surface states
Abstract: International audience; The perfomance of hematite and Ti-substituted hematite nanorods as photoanodes for solar water splitting was quantitavely evaluated from photoelectrochemical point of view. The nanostructure, morphology and chemical / electronic structure were characterized using various complementary methods, including X-ray diffraction, electron microscopy, X-ray photoelectron spectroscopy and scanning transmission X-ray microscopy. The presence of both reductive and oxidative surface states was evidenced and their impact on the photoelectrochemical efficiency was characterized. We show that both electronic conduction enhancement provided by the Ti substitution and charge transfer promoted by oxidative surface states improve solar water splitting performance.
Published: 2020
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26. Hydration Properties and Interlayer Organization in Synthetic C-S-H

Author: Dris Ihiawakrim, Cédric Roosz, Nicolas Maubec, Francis Claret, Valérie Montouillout, Sylvain Grangeon, Pierre Henocq, Ovidiu Ersen, Stéphane Gaboreau, Cédric Carteret, Conditions Extrêmes et Matériaux : Haute Température et Irradiation (CEMHTI), and Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université d'Orléans (UO)
Subjects: Materials science, Analytical chemistry, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, Adsorption, Desorption, Monolayer, Electrochemistry, medicine, [CHIM]Chemical Sciences, General Materials Science, Dehydration, Calcium silicate hydrate, Spectroscopy, Surfaces and Interfaces, Partial pressure, 021001 nanoscience & nanotechnology, Condensed Matter Physics, medicine.disease, 0104 chemical sciences, chemistry, [SDE]Environmental Sciences, Diffuse reflection, 0210 nano-technology, Water vapor
Abstract: International audience; Water in calcium silicate hydrate (C-S-H) is one of the key parameters driving the macroscopic behavior of cement materials for which water vapor partial pressure has an impact on Young's modulus and the volumic properties. Several samples of C-S-H with a bulk Ca/Si ratio ranging between 0.6 and 1.6 were characterized to study their dehydration/hydration behavior under water-controlled conditions using 29 Si NMR, water adsorption volumetry, X-ray diffraction, and Fourier-transform near-infrared diffuse reflectance under various water pressures. Coherent with several previous studies, it was observed that an increase in the Ca/Si ratio is due to the progressive omission of Si bridging tetrahedra, with the resulting charge being compensated for by interlayer Ca, and that water conditioning influences the layer-to-layer distance and the achieved NMR spectral resolution. Water desorption experiments exhibit one step toward low relative pressure, accompanied by a decrease in the layer-to-layer distance. When sufficient energy is provided to the system (T ≥ 40°C under vacuum) to remove the interlayer water, the shrinkage/swelling is partially reversible in our experimental conditions. A change in layer-to-layer distance of less than 3 Å is measured in the C-S-H between the wet and dried states. When the bridging SiO 2 tetrahedra are omitted, interlayer Ca interacts with layer O and water interacts with the cations and potentially with the surfaces. This structural organization is interpreted as a mid-plane monolayer of water in the interlayer space, this latter accounting for about 30% of the volume of C-S-H particles.
Published: 2020
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27. Efficiency of pyoverdines in iron removal from flocking asbestos waste: An innovative bacterial bioremediation strategy

Author: Dris Ihiawakrim, Sébastien R. David, Valérie A. Geoffroy, Robert Regis, Biotechnologie et signalisation cellulaire (BSC), and Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche de l'Ecole de biotechnologie de Strasbourg (IREBS)
Subjects: Siderophore, Environmental Engineering, Asbestos, Serpentine, Health, Toxicology and Mutagenesis, Iron, Siderophores, 010501 environmental sciences, Wastewater, medicine.disease_cause, 01 natural sciences, Asbestos, Water Purification, 03 medical and health sciences, chemistry.chemical_compound, Bioremediation, Pseudomonas, medicine, Environmental Chemistry, Waste Management and Disposal, 030304 developmental biology, 0105 earth and related environmental sciences, 0303 health sciences, Pyoverdine, biology, Chemistry, [SDE.IE]Environmental Sciences/Environmental Engineering, Biodegradation, biology.organism_classification, Pollution, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Biodegradation, Environmental, Environmental chemistry, Iron removal, Asbestos, Amosite, Oligopeptides, Bacteria
Abstract: International audience; The use of asbestos-containing products has been banned in many countries since the beginning of the 80's due to its carcinogenic properties. However, asbestos is widely present in private and public buildings, resulting in the need to process a vast amount of asbestos-containing waste. Among the current technologies for the destruction of asbestos fibers, biodegradation by fungi, lichens, and, more recently, bacteria has been described. We previously reported the involvement of the bacterial siderophore pyoverdine in the release of iron from the two asbestos groups, serpentines and amphiboles. Among the large diversity encountered in the pyoverdine family, we examined whether these siderophores can alter flocking asbestos waste as well. All the tested pyoverdines were efficient in chrysotile-gypsum and amosite-gypsum weathering, although some exhibited higher iron dissolution. Iron was solubilized by pyoverdines from Pseudomonas aeruginosa and mandelii in a time-dependent manner from chrysotile-gypsum within 24 hours. Renewal of pyoverdine-containing supernatant every 24 or 96 hours allowed iron removal from chrysotile-gypsum at each cycle, until a limit was reached after 42 days of total incubation. Moreover, the dissolution was concentration-dependent, as demonstrated for the pyoverdine of *Revised Manuscript Texte 2 P. mandelii. Pyoverdine-asbestos weathering could therefore become an innovative method to reduce anthropogenic waste.
Published: 2020
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28. Biodeterioration of asbestos cement by siderophore-producing Pseudomonas

Author: Agathe Jaouen, Sébastien R. David, Valérie A. Geoffroy, Dris Ihiawakrim, Biotechnologie et signalisation cellulaire (BSC), and Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche de l'Ecole de biotechnologie de Strasbourg (IREBS)
Subjects: Siderophore, Environmental Engineering, Health, Toxicology and Mutagenesis, Iron, 0211 other engineering and technologies, Siderophores, 02 engineering and technology, 010501 environmental sciences, medicine.disease_cause, 01 natural sciences, Asbestos, chemistry.chemical_compound, Bioremediation, Pseudomonas, medicine, Environmental Chemistry, Waste Management and Disposal, Carcinogen, 0105 earth and related environmental sciences, 021110 strategic, defence & security studies, Pyoverdine, biology, [SDE.IE]Environmental Sciences/Environmental Engineering, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Pollution, Asbestos cement, chemistry, Environmental chemistry, Pseudomonas aeruginosa, Bacteria
Abstract: International audience; Since the ban on the use of asbestos due to its carcinogenic properties, the removal of asbestos cement, representing the major asbestos-containing waste, has proven to be a challenge in most industrial countries. Asbestos-containing products are mainly disposed of in landfills and have remained untreated. Bioremediation involving bacteria previously reported the ability of Pseudomonas aeruginosa to release iron from flocking asbestos waste through a siderophore-driven mechanism. We examined the involvement of siderophore-producing Pseudomonas in the biodeterioration of asbestos cement. Iron and magnesium solubilization were evaluated by specific siderophore-producing mutants. The absence of one of the two siderophores affected iron extraction, whereas equivalent dissolution as that of the control was observed in the absence of siderophore. Both pyoverdine and pyochelin biosynthesis was repressed in the presence of asbestos cement, suggesting iron bioavailability from the waste. We compared the efficiency of various pyoverdines to scavenge iron from asbestos cement waste that revealed the efficiency of all pyoverdines. Pyoverdines were efficient in iron Revised Manuscript Texte removal extracted continuously, with no evident extraction limit, in long-term weathering experiments with these pyoverdines. The optimization of pyoverdine-asbestos weathering may allow the development of a bioremediation process to avoid the disposal of such waste in landfills.
Published: 2020
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29. Iron removal from raw asbestos by siderophores-producing Pseudomonas

Author: Dris Ihiawakrim, Sébastien R. David, Valérie A. Geoffroy, Robert Regis, Biotechnologie et signalisation cellulaire (BSC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche de l'Ecole de biotechnologie de Strasbourg (IREBS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, and Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)
Subjects: Siderophore, Environmental Engineering, Asbestos, Serpentine, Health, Toxicology and Mutagenesis, Iron, 0211 other engineering and technologies, Siderophores, 02 engineering and technology, 010501 environmental sciences, Bacterial growth, medicine.disease_cause, 01 natural sciences, Asbestos, chemistry.chemical_compound, Phenols, Pseudomonas, Chrysotile, medicine, Environmental Chemistry, [CHIM]Chemical Sciences, Waste Management and Disposal, Dissolution, Edetic Acid, 0105 earth and related environmental sciences, 021110 strategic, defence & security studies, Pyoverdine, biology, Chemistry, Extraction (chemistry), Asbestos, Crocidolite, biology.organism_classification, Pollution, Thiazoles, Biofilms, Asbestos, Amosite, Oligopeptides, Nuclear chemistry
Abstract: Asbestos, mineral present in soil, are highly toxic due to the presence of iron. Microbes-mineral interactions occur naturally through various processes leading to their alteration. We examined the effect of siderophore-producing Pseudomonas with a particular focus on the role of pyoverdine and pyochelin on raw asbestos fibers such as amosite, crocidolite and chrysotile. We compared the efficiency of pyoverdine to the iron chelating agent EDTA in the release of iron from raw asbestos fibers. Pyoverdine was able to extract iron from all the tested raw asbestos with the higher efficiency observed for chrysotile and crocidolite. When asbestos were grinded, the iron removal was more important for all types. We monitored the effect of bacterial growth and siderophores containing bacterial supernatant on raw asbestos dissolution by solution chemistry analysis and transmission electron microscopy. The siderophore-containing supernatant allowed a higher iron solubilisation than the one obtained after bacterial growth. Moreover, the iron dissolution was faster with pyoverdine-containing supernatant than pyochelin-containing supernatant, with approximately the same iron level for the maximum extraction with a delay of 48 h. Our study clearly showed the involvement of bacterial siderophores, pyoverdine and pyochelin on chrysotile, crocidolite and amosite fibers weathering.
Published: 2020
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30. Flocking asbestos waste, an iron and magnesium source for Pseudomonas

Author: Sarah Fritsch, Valérie A. Geoffroy, Dris Ihiawakrim, Anne Forster, Sébastien R. David, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Biotechnologie et signalisation cellulaire (BSC), Université de Strasbourg (UNISTRA)-Institut de recherche de l'Ecole de biotechnologie de Strasbourg (IREBS)-Centre National de la Recherche Scientifique (CNRS), Agence de l'Environnement et de la Maîtrise de l'Energie (ADEME), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), and CCSD, Accord Elsevier
Subjects: Siderophore, Environmental Engineering, 010504 meteorology & atmospheric sciences, Iron, Microorganism, Siderophores, chemistry.chemical_element, 010501 environmental sciences, Bacterial growth, medicine.disease_cause, 01 natural sciences, Asbestos, chemistry.chemical_compound, Pseudomonas, medicine, Environmental Chemistry, Magnesium, [SDV.MP] Life Sciences [q-bio]/Microbiology and Parasitology, Waste Management and Disposal, 0105 earth and related environmental sciences, Pyoverdine, biology, biology.organism_classification, Pollution, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, chemistry, Environmental chemistry, Pseudomonas aeruginosa, Alteration, Bacteria
Abstract: Iron and magnesium are essential nutrients for most microorganisms. In the environment, the availability of iron is low relative to that of magnesium. Microorganisms have developed various iron acquisition systems, which have been well studied, whereas few studies have examined magnesium acquisition. The production of siderophores is one of the efficient strategies widely used to sustain iron nutritional requirements. Many studies have shown that minerals, such as clays, iron oxides, and silicates, can serve as nutrient sources for bacteria. Asbestos, a natural fibrous silicate present in soil contains iron and/or magnesium, depending on the species of asbestos. Our aim was to study the acquisition of iron and magnesium from flocking asbestos waste by Pseudomonas aeruginosa and the involvement of the siderophores, pyoverdine and pyochelin. Flocking asbestos waste promoted growth under iron- and magnesium-limited conditions, together with a decrease in pyoverdine production, correlating with the dissolution of iron from the waste. In long-term experiments, flocking asbestos waste provided these two essential elements for bacterial growth and resulted in a decrease of iron in asbestos fibers. Among the enzymes required for pyochelin and pyoverdine synthesis, PchA and PvdJ were tagged with the fluorescent protein mCherry to analyze the expression patterns of proteins involved in siderophore production. Both enzymes were produced in the presence of flocking asbestos waste, suggesting a role of the pyoverdine and pyochelin pathway in asbestos dissolution. We investigated the involvement of each siderophore in iron and magnesium removal using mutants in one or both siderophore pathways. We observed a significant increase in iron extraction in the presence of siderophores and the absence of one of the two siderophores could be compensated by the other. Flocking asbestos waste represents an iron and magnesium source for P. aeruginosa, with iron removal linked to a siderophore-driven mechanism.
Published: 2020
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31. Ideality factor and barrier height for a GaN nanomembrane electrically contacted with a tungsten nano-tip in a TEM

Author: M. Benaissa, Dris Ihiawakrim, R. El Bouayadi, Ovidiu Ersen, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), and Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010302 applied physics, Materials science, [PHYS.PHYS]Physics [physics]/Physics [physics], business.industry, General Physics and Astronomy, Nanoprobe, chemistry.chemical_element, Gallium nitride, 02 engineering and technology, Edge (geometry), Tungsten, 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, chemistry.chemical_compound, chemistry, Transmission electron microscopy, law, 0103 physical sciences, Nano, Optoelectronics, Scanning tunneling microscope, 0210 nano-technology, business, Lithography
Abstract: In the present article, the electrical characteristics of a freestanding gallium nitride nanomembrane in contact with a tungsten nanoprobe are evaluated using scanning tunneling microscopy in an aberration-corrected transmission electron microscope without any lithographic patterning. We report here barrier height ( Φ B = 0.33 ± 0.05 eV and ideality factor ( η W / GaN − NM = 1.620 ± 0.07 ) parameters as extracted from I–V characteristic curve. Our experimental findings, combined with analytical calculations, show that the use of nanosized edge contacts results in a reduced barrier height, which is very promising for achieving a high ‘on’ current, large photoresponse, and high-frequency operation in FET devices.
Published: 2020
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32. A Confinement‐Driven Nucleation Mechanism of Metal Oxide Nanoparticles Obtained via Thermal Decomposition in Organic Media

Author: Geoffrey Cotin, Benoît Heinrich, Francis Perton, Céline Kiefer, Gregory Francius, Damien Mertz, Barbara Freis, Benoit Pichon, Jean‐Marc Strub, Sarah Cianférani, Nathalie Ortiz Peña, Dris Ihiawakrim, David Portehault, Ovidiu Ersen, Amir Khammari, Matthieu Picher, Florian Banhart, Clement Sanchez, and Sylvie Begin‐Colin
Subjects: Biomaterials, Iron, Stearates, Aucun, Metal Nanoparticles, Oxides, General Materials Science, General Chemistry, Ferric Compounds, Culture Media, Biotechnology
Abstract: Thermal decomposition is a very efficient synthesis strategy to obtain nanosized metal oxides with controlled structures and properties. For the iron oxide nanoparticle synthesis, it allows an easy tuning of the nanoparticle's size, shape, and composition, which is often explained by the LaMer theory involving a clear separation between nucleation and growth steps. Here, the events before the nucleation of iron oxide nanocrystals are investigated by combining different complementary in situ characterization techniques. These characterizations are carried out not only on powdered iron stearate precursors but also on a preheated liquid reaction mixture. They reveal a new nucleation mechanism for the thermal decomposition method: instead of a homogeneous nucleation, the nucleation occurs within vesicle-like-nanoreactors confining the reactants. The different steps are: 1) the melting and coalescence of iron stearate particles, leading to "droplet-shaped nanostructures" acting as nanoreactors; 2) the formation of a hitherto unobserved iron stearate crystalline phase within the nucleation temperature range, simultaneously with stearate chains loss and Fe(III) to Fe(II) reduction; 3) the formation of iron oxide nuclei inside the nanoreactors, which are then ejected from them. This mechanism paves the way toward a better mastering of the metal oxide nanoparticles synthesis and the control of their properties.
Published: 2022
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33. Anions and cations distribution in M 5+ /N 3- co-alloyed TiO 2 nanotubular structures for photo-electrochemical water splitting

Author: Valérie Keller, Dris Ihiawakrim, Thomas Favet, Thomas Cottineau, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nanostructure, Materials science, Anodizing, Mechanical Engineering, Doping, Analytical chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Thermal treatment, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electrochemistry, 01 natural sciences, 0104 chemical sciences, chemistry.chemical_compound, chemistry, X-ray photoelectron spectroscopy, 13. Climate action, Mechanics of Materials, Titanium dioxide, Water splitting, General Materials Science, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract: Co-alloyed (M,N) titanium dioxide nanotubes were synthesized by a simple anodization process with M-Ti alloys (M = Ta or Nb), followed by a thermal treatment in ammonia to introduce nitrogen in those nanostructure. The photo-electrochemical performances of these co-alloyed samples was compared with the ones of N doped and undoped TiO 2 NTs. Different conditions of thermal treatment under ammonia were studied in order to control the amount of nitrogen introduced in the TiO 2 structure and tend to achieve a balance of charges between Ta 5+ /Nb 5+ cations and N 3- anions. The structure and composition of these materials were characterized by X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM) EDX mapping. This combination of methods confirm the successful introduction of doping atoms, and allowed us to estimate the amount of M 5+ cations and N 3- anions in the TiO 2 NTs. TEM EDX mapping indicates a heterogeneous distribution of Nb 5+ and Ta 5+ cations in the nanotubes that can originate from the use of highly concentrated alloys. External quantum efficiency measurements were used to determine the photo-electrochemical activity of our samples in different spectral domains. A significant improvement of activity in the visible region of the solar spectra was observed for co-alloyed TiO 2 samples when compared to undoped nanotubes but also when compared to N doped TiO 2 . The obtained results indicate that the parameters of the NH 3 thermal treatments should be finely controlled to improve the conversion efficiency in the visible domain for the co-alloyed samples by introducing a precise amount of N 3- in substitution of oxygen in the TiO 2 lattice and to avoid the damaging of the nanotubular structure.
Published: 2018
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34. Shedding Light on Functional Hybrid Nanocomposites 19th Century Paint Medium

Author: Ovidiu Ersen, Frédéric Gobeaux, Dris Ihiawakrim, Maguy Jaber, Marco Faustini, Cristina Coelho-Diogo, Christel Gervais, Philippe Walter, Hélène Pasco, Clément Sanchez, Laurence de Viguerie, Laboratoire d'Archéologie Moléculaire et Structurale (LAMS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Matériaux Hybrides et Procédés (LCMCP-MHP ), Matériaux Hybrides et Nanomatériaux (LCMCP-MHN), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des matériaux de Paris-Centre (IMPC), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut d’Etudes Avancées de l’Université de Strasbourg - Institute for Advanced Study (USIAS), Université de Strasbourg (UNISTRA), ANR-10-LABX-0068,MiChem,Multi-Scale Integrative Chemistry : From Single Molecule to Nano-edifices(2010), Palacin, Serge, Multi-Scale Integrative Chemistry : From Single Molecule to Nano-edifices - - MiChem2010 - ANR-10-LABX-0068 - LABX - VALID, Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), University of Strasbourg Institute of Advanced Study (USIAS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique
Subjects: [CHIM.MATE] Chemical Sciences/Material chemistry, Nanocomposite, Materials science, 010405 organic chemistry, Mastic Resin, Nanotechnology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Biomaterials, Hybrid system, Electrochemistry, Hybrid material, Lead oxide
Abstract: International audience; British 19th century painters formulated gelled systems often described as ideal paint mediums. These so-called megilps or gumtions are based on common paint materials like linseed oil, lead acetate, and mastic resin, and allowed painters such as J.M.W Turner to improve their paint's properties and achieve unprecedented effects in an age of innovation. To propose a structural scheme of these hybrid systems of unprecedented complexity, it is paramount to design and study model systems using a broad combination of advanced spectroscopic techniques and microscopies. Through this approach, gel Mediums can be described as nanocomposites based on lead metallogels co-existing with lead oxide nanoparticles and a partially polymerized fraction. These functional hybrid materials created a real breakthrough on 19th century paints performances.
Published: 2021
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35. Morphological and Structural Evolution of Co

Author: Nathaly, Ortiz Peña, Dris, Ihiawakrim, Madeleine, Han, Benedikt, Lassalle-Kaiser, Sophie, Carenco, Clément, Sanchez, Christel, Laberty-Robert, David, Portehault, and Ovidiu, Ersen
Abstract: Unveiling the mechanism of electrocatalytic processes is fundamental for the search of more efficient and stable electrode materials for clean energy conversion devices. Although several
Published: 2019

36. Photon management properties of Yb-doped SnO2 nanoparticles synthesized by the sol–gel technique

Author: Guy Schmerber, Abdelilah Slaoui, Hervé Rinnert, Aziz Dinia, Silviu Colis, Damien Aureau, Karima Bouras, Jean-Luc Rehspringer, Dris Ihiawakrim, Laboratoire des sciences de l'ingénieur, de l'informatique et de l'imagerie (ICube), Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Université de Strasbourg (UNISTRA)-Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Les Hôpitaux Universitaires de Strasbourg (HUS)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)
Subjects: Materials science, Photoluminescence, business.industry, Band gap, Doping, General Physics and Astronomy, Nanoparticle, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, 0104 chemical sciences, Ion, Semiconductor, X-ray photoelectron spectroscopy, Optoelectronics, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Physical and Theoretical Chemistry, 0210 nano-technology, business, ComputingMilieux_MISCELLANEOUS, Sol-gel
Abstract: International audience; SnO2 is a transparent large band gap semiconductor, particularly interesting for optoelectronic and photovoltaic devices, mainly because its conduction can be easily tuned by doping or by modulating the amount of oxygen vacancies. Besides, rare earth doping was successfully exploited for up conversion properties. Here we report on the functionalization of SnO2 nanoparticles with optically active Yb3+ ions using the sol–gel method, which allows UV to NIR spectral (down) conversion. As starting solutions we used stable non-alkoxide metal–organic compounds, which is rather uncommon. Transmission electron microscopy analysis demonstrated the formation of small well-crystallized nanoparticles while X-ray photoelectron spectroscopy measurements have revealed that the Yb is well inserted in the host matrix and has a 3+ valence state. All nanoparticles present large absorption in the UV-visible range (250 to 550 nm) and a band gap that decreases down to 2.72 eV upon doping. The UV energy converted into NIR on the basis of efficient energy transfer from SnO2 to the Yb3+ ions ranges between 250 and 400 nm. Reference undoped SnO2 nanoparticles with a mean size of 20 nm allow converting UV light into broad visible emission centered at 650 nm. The incorporation of up to 3.5 at% of Yb3+ ions into the SnO2 host matrix results in a spectacular decrease of the nanoparticle size down to 6.6 nm. This allowed also the shift of the photoluminescence to NIR in the 970–1050 nm range. The energy level structure of Yb3+ in SnO2 was successfully determined from the deconvolution of the Yb emission. This emission is significantly enhanced by increasing the doping level. All optical measurements suggest that these nanoparticles can be efficiently used as down-shifting converters.
Published: 2019
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37. Morphological and Structural Evolution of Co3O4 Nanoparticles Revealed by in Situ Electrochemical Transmission Electron Microscopy during Electrocatalytic Water Oxidation

Author: Nathaly Ortiz Peña, Christel Laberty-Robert, David Portehault, Sophie Carenco, Ovidiu Ersen, Clément Sanchez, Dris Ihiawakrim, Benedikt Lassalle-Kaiser, Madeleine Han, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Novel Advanced Nano-Objects (LCMCP-NANO), Matériaux Hybrides et Nanomatériaux (LCMCP-MHN), Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Chaire Chimie des matériaux hybrides, Reactive Materials for Electrochemical Systems (LCMCP-RMES ), Agence Nationale de la Recherche ANR, ANR-16-CE05-0011,InSiChem,Etude ' in-situ ' et multiéchelle d'électrocatalyseurs pour la conversion d'énergie(2016), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique
Subjects: In situ, Materials science, General Engineering, Oxygen evolution, General Physics and Astronomy, Nanoparticle, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrochemistry, Electrocatalyst, 01 natural sciences, 7. Clean energy, Structural evolution, 0104 chemical sciences, Chemical engineering, Transmission electron microscopy, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, General Materials Science, 0210 nano-technology, Cobalt oxide, ComputingMilieux_MISCELLANEOUS
Abstract: Unveiling the mechanism of electrocatalytic processes is fundamental for the search of more efficient and stable electrode materials for clean energy conversion devices. Although several in situ te...
Published: 2019
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38. Few-Layer Graphene from Mechanical Exfoliation of Graphite-Based Materials: Structure-Dependent Characteristics

Author: Izabela Janowska, François Le Normand, Vasiliki Papaefthimiou, Thierry Romero, Dris Ihiawakrim, Sandra Paszkiewicz, Azhar A. Pirzado, Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des sciences de l'ingénieur, de l'informatique et de l'imagerie (ICube), Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), West Pomeranian University of Technology Szczecin, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Université de Strasbourg (UNISTRA)-Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Les Hôpitaux Universitaires de Strasbourg (HUS)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), and Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE)
Subjects: Materials science, General Chemical Engineering, FOS: Physical sciences, Applied Physics (physics.app-ph), 02 engineering and technology, Conductivity, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, lcsh:Chemistry, [SPI]Engineering Sciences [physics], Nuclear reaction analysis, [CHIM]Chemical Sciences, Graphite, Composite material, Electrical conductor, graphene nanocomposites, Supercapacitor, Condensed Matter - Materials Science, Nanocomposite, General Engineering, Materials Science (cond-mat.mtrl-sci), Physics - Applied Physics, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, few-layer graphene, General Energy, lcsh:QD1-999, nuclear reaction analysis, Electrode, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], mechanical exfoliation, Elongation, 0210 nano-technology, conductive layer
Abstract: We present a high-scale method to produce few-layer graphene (FLG) based on the mechanical exfoliation of graphite and compare the obtained FLG with the one reported earlier arising from pencil lead ablation. Several elements were modified and improved in the new approach. The purification and the ablation set-up were simplified, and the morphology of the FLG was modified and improved in view of some applications. The morphology-dependent properties of FLGs, lead-FLG, and graphite-FLG as conductive layers and in nanocomposites were investigated. The newly obtained FLG had a higher aspect ratio (high lateral size vs thickness/higher 2D aspect), which is reflected by enhanced transparency&ndash, conductivity features of the layer (film) and elongation-at-break behavior of the polymer composites. On the contrary, the nanocomposite containing lead-FLG showed, for instance, excellent gas barrier properties due to the multi-step structure of the lead-FLG flakes. Such structure exhibited less 2D and more 3D character, which can be highly suitable for applications where the presence of active/reactive edges is beneficial, e.g., in catalysis or supercapacitors&rsquo, electrodes. Nuclear reaction analysis was employed to investigate the morphology of graphite-FLG film.
Published: 2019
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39. Study by advanced transmission electron microscopy techniques fragile materials

Author: Dris Ihiawakrim, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université de Strasbourg, and Ovidiu Ersen
Subjects: In-situ, Environmental, Sensitives materials, Développement méthodologie et techniques, Irradiation, Cryo-Tomographie, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Methodology and techniques development, Microscopie électronique en transmission, Transmission electron microscopy, Cryo-Tomography, Matériaux sensibles, Cryo-EM, Environnemental
Abstract: The present manuscript shows the importance of methodological and technical development to identify and to unblock locks preventing the analysis of hybrid and complex materials that undergo degradation under electron beam irradiation. We have shown that beam-induced damage to the sample only appears above some specific threshold of current density. Such a threshold depends on the nature of the material and on its morphological and structural characteristics. These developments in synergy with the use of Cryo-EM, allowed us to expose the architecture of carbon-based hybrid materials, measure the variation of the lamellar distance in a perovskite according to the molecular spacer and to the positioning of the metal, identify the interactions at the interface between two molecular crystals, and the 3D quantification of the functionalization within a MOF. Lastly, we brought to light the processes of nucleation and growth of iron oxide by in-situ liquid phase TEM.; Le travail présenté dans ce manuscrit a montré l’importance du développement méthodologique et technique pour identifier et débloquer les verrous empêchant l’analyse de matériaux hybrides et complexes qui se dégradent sous irradiation par un faisceau d’électrons. Nous avons mis en évidence que des dégâts sur l’échantillon produits par les électrons n’apparaissent qu’au-dessus d'un certain seuil de densité de courant électronique qui dépend de la nature du matériau et de ses caractéristiques morphologiques et structurales. Ces développements couplés à la Cryo-EM, nous ont permis de mettre en évidence l’architecture des matériaux hybrides à base de carbone, la variation de la distance lamellaire dans une pérovskite en fonction de la molécule insérée et le positionnement du métal, d’identifier les interactions à l’interface entre deux cristaux moléculaires et la quantification 3D de la fonctionnalisation d’un MOF. Dans la dernière partie, nous avons mis en évidence les processus de nucléation et de croissance d’oxyde de fer par MET in-situ en phase liquide.
Published: 2019

40. Spin State As a Probe of Vesicle Self-Assembly

Author: Andreea Pasc, Julian Eastoe, Dris Ihiawakrim, Sanghoon Kim, C. Bellouard, Ovidiu Ersen, Nadia Canilho, Sarah E. Rogers, Structure et Réactivité des Systèmes Moléculaires Complexes (SRSMC), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), School of Chemistry, University of Bristol [Bristol], ISIS Neutron and Muon Source (ISIS), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC)-Science and Technology Facilities Council (STFC), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), IMPACT N4S, and ANR-15-IDEX-0004,LUE,Isite LUE(2015)
Subjects: Physics::Biological Physics, Aqueous solution, Spin states, Chemistry, Vesicle, Analytical chemistry, 02 engineering and technology, General Chemistry, Neutron scattering, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Biochemistry, Catalysis, 0104 chemical sciences, Quantitative Biology::Subcellular Processes, Condensed Matter::Soft Condensed Matter, Paramagnetism, Magnetization, Colloid and Surface Chemistry, Chemical physics, Transmission electron microscopy, [CHIM]Chemical Sciences, Self-assembly, 0210 nano-technology
Abstract: International audience; A novel system of paramagnetic vesicles was designed using ion pairs of iron-containing surfactants. Unilamellar vesicles (diameter approximate to 200 nm) formed spontaneously and were characterized by cryogenic transmission electron microscopy, nanoparticle tracking, analysis, and light and small-angle neutron scattering. Moreover, for the first time, it is shown that magnetization measurements can be used to investigate self-assembly of such functionalized systems, giving information on the vesicle compositions and distribution Of surfactants between the bilayers and the aqueous bulk.
Published: 2016
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41. Enzymatically Active Polydopamine @ Alkaline Phosphatase Nanoparticles Produced by NaIO4 Oxidation of Dopamine

Author: Dris Ihiawakrim, Ovidiu Ersen, Vincent Ball, Salima El Yakhlifi, univOAK, Archive ouverte, Biomatériaux et Bioingénierie (BB), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, and Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)
Subjects: chemical_engineering, layer-by-layer films, [SDV.BIO]Life Sciences [q-bio]/Biotechnology, enzymatic activity, Biomedical Engineering, Nanoparticle, Bioengineering, 02 engineering and technology, 010402 general chemistry, lcsh:Technology, 01 natural sciences, Biochemistry, Article, Biomaterials, chemistry.chemical_compound, Dopamine, medicine, melanin-like nanoparticles, lcsh:T, Chemistry, Sodium periodate, Conformal coating, Sciences du Vivant [q-bio]/Biotechnologies, 021001 nanoscience & nanotechnology, Polyelectrolyte, [SDV.BIO] Life Sciences [q-bio]/Biotechnology, 0104 chemical sciences, Chemical engineering, sodium periodate, Molecular Medicine, Particle, Alkaline phosphatase, 0210 nano-technology, Biosensor, Biotechnology, medicine.drug
Abstract: Polydopamine (PDA) deposition, obtained from the oxidation of dopamine and other catecholamines, is a universal way to coat all known materials with a conformal coating which can subsequently be functionalized at will. The structural analogies between polydopamine and eumelanin, the black-brown pigment of the skin, were incited to produce stable polydopamine nanoparticles in solution, instead of amorphous precipitates obtained from the oxidation of dopamine. Herein, we demonstrate that size-controlled and colloidally stable PDA-based nanoparticles can be obtained in acidic conditions, where spontaneous auto-oxidation of dopamine is suppressed, using sodium periodate as the oxidant and a protein, like alkaline phosphatase (ALP), as a templating agent. The size of the PDA@ALP nanoparticles depends on the dopamine/enzyme ratio and the obtained particles display enzymatic activity of alkaline phosphatase, with an activity extending up to two weeks after particle synthesis. The PDA@ALP nanoparticles can be engineered in polyelectrolyte multilayered films to potentially design model biosensors. Keywords: enzymatic activity; layer-by-layer films; melanin-like nanoparticles; sodium periodate.
Published: 2018
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42. Unravelling the Thermal Decomposition Parameters for The Synthesis of Anisotropic Iron Oxide Nanoparticles

Author: Christophe Lefevre, Simona Moldovan, Céline Kiefer, Sylvie Begin-Colin, Cristina Blanco-Andujar, Dris Ihiawakrim, Ovidiu Ersen, Benoit P. Pichon, Damien Mertz, Geoffrey Cotin, Francis Perton, Moldovan, Simona, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Groupe de physique des matériaux (GPM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), and Normandie Université (NU)
Subjects: Materials science, synthesis, General Chemical Engineering, precursor, Iron oxide, Nucleation, Nanoparticle, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Article, lcsh:Chemistry, 03 medical and health sciences, chemistry.chemical_compound, Stearate, [CHIM] Chemical Sciences, [CHIM]Chemical Sciences, General Materials Science, shape control, thermal decomposition, 030304 developmental biology, 0303 health sciences, nanotechnology, 030302 biochemistry & molecular biology, Thermal decomposition, iron oxide nanoparticles, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Oleic acid, Magnetic hyperthermia, chemistry, Chemical engineering, lcsh:QD1-999, 0210 nano-technology, Iron oxide nanoparticles
Abstract: Iron oxide nanoparticles are widely used as a contrast agent in magnetic resonance imaging (MRI), and may be used as therapeutic agent for magnetic hyperthermia if they display in particular high magnetic anisotropy. Considering the effect of nanoparticles shape on anisotropy, a reproducible shape control of nanoparticles is a current synthesis challenge. By investigating reaction parameters, such as the iron precursor structure, its water content, but also the amount of the surfactant (sodium oleate) reported to control the shape, iron oxide nanoparticles with different shape and composition were obtained, in particular, iron oxide nanoplates. The effect of the surfactant coming from precursor was taking into account by using in house iron stearates bearing either two or three stearate chains and the negative effect of water on shape was confirmed by considering these precursors after their dehydration. Iron stearates with three chains in presence of a ratio sodium oleate/oleic acid 1:1 led mainly to nanocubes presenting a core-shell Fe1&minus, xO@Fe3&minus, xO4 composition. Nanocubes with straight faces were only obtained with dehydrated precursors. Meanwhile, iron stearates with two chains led preferentially to the formation of nanoplates with a ratio sodium oleate/oleic acid 4:1. The rarely reported flat shape of the plates was confirmed with 3D transmission electronic microscopy (TEM) tomography. The investigation of the synthesis mechanisms confirmed the major role of chelating ligand and of the heating rate to drive the cubic shape of nanoparticles and showed that the nanoplate formation would depend mainly on the nucleation step and possibly on the presence of a given ratio of oleic acid and chelating ligand (oleate and/or stearate).
Published: 2018
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43. A high pressure pathway toward boron-based nanostructured solids

Author: Guillaume Gouget, David Portehault, Yann Le Godec, Oleksandr O. Kurakevych, Dris Ihiawakrim, Ovidiu Ersen, Simon Delacroix, Rémi Grosjean, Patricia Beaunier, Corinne Chanéac, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Réactivité de Surface (LRS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Christophe Calers from the Centre of Institute of Materials of Paris Centre is acknowledged for XPS measurements. The authors thank the Centre National de la Recherche Scientifique its Energy Unit and French state funds managed by the ANR within the Investissements d'Avenir programme ANR-11-IDEX-0004-02, more specifically within the Cluster of Excellence MATISSE, for funding. The Agence Nationale de la Recherche (project ANR-2011-BS08-018), Sorbonne Universités-UPMC, Collège de France and the METSA (Microscopie Electronique et Sonde Atomique) network are also acknowledged for financial support., ANR-11-IDEX-0004,SUPER,Sorbonne Universités à Paris pour l'Enseignement et la Recherche(2011), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Diffraction, Nanocomposite, Materials science, chemistry.chemical_element, Nanoparticle, Heterojunction, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, law.invention, Inorganic Chemistry, chemistry, Chemical engineering, Nanocrystal, FOS: Chemical sciences, Transmission electron microscopy, law, Crystallization, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Boron
Abstract: International audience; Inorganic nanocomposites made of an inorganic matrix containing nanoparticle inclusions provide materials of advanced mechanical, magnetic, electrical properties and multifunctionality. The range of compounds that can be implemented in nanocomposites is still narrow and new preparation methods are required to design such advanced materials. Herein, we describe how the combination of nanocrystal synthesis in molten salts with subsequent heat treatment at a pressure in the GPa range gives access to a new family of boron-based nanocomposites. With the case studies of HfB2/β-HfB2O5 and CaB6/CaB2O4(IV), we demonstrate by X-ray diffraction and through (scanning) transmission electron microscopy the crystallization of borate matrices into rare compounds and unique nanostructured solids, while metal boride nanocrystals remain dispersed in the matrix and maintain small sizes below 30 nm, thus demonstrating a new multidisciplinary approach toward nanoscaled heterostructures.
Published: 2018
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44. Polymer-free electrospinning of tannic acid and cross-linking in water for hybrid supramolecular nanofibres

Author: Pascal Hébraud, Dris Ihiawakrim, Guy Schlatter, Anne Hébraud, Domitille Mailley, Florent Meyer, Manon Allais, Vincent Ball, Biomatériaux et Bioingénierie (BB), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Biomatériaux : Processus biophysiques et biologiques aux interfaces, Université Louis Pasteur - Strasbourg I-Faculté de Chirurgie Dentaire-Institut National de la Santé et de la Recherche Médicale (INSERM), Laboratoire d'Ingenierie des Polymères pour les Hautes Technologies, and Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)
Subjects: chemistry.chemical_classification, Chemical substance, Materials science, Molar mass, Sodium periodate, Supramolecular chemistry, 02 engineering and technology, Polymer, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Electrospinning, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Dynamic light scattering, Chemical engineering, Tannic acid, [CHIM]Chemical Sciences, General Materials Science, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract: Electrospinning is the process of choice allowing the preparation of nanofibrous materials from a solution usually based on a high molar mass polymer. The solution must bring enough chain entanglements to avoid any breaking or Rayleigh instability of the electrospun jet resulting thus in the deposition of a continuous and regular solid nanofibre. It has been however shown that some few non-polymeric molecules can be electrospun without using a carrier polymer. We demonstrate here the case of tannic acid. Indeed, it was possible to electrospin this molecule solubilised in a mixture of water and ethanol as well as in pure water. Rheology, dynamic light scattering and cryo-TEM highlight the formation of tannic acid aggregates in solution. Above a critical concentration, these aggregates form a supramolecular interconnected network strong enough to allow the electrospinning of a continuous and regular nanofibre. The resulting nanoweb is mechanically stable and can be handled and wrapped. Furthermore, as opposed to the other small molecules for which polymer-free electrospinning was also demonstrated, tannic acid nanowebs can be efficiently cross-linked in water either by oxidative reaction with sodium periodate or, most interestingly, with FeIII by a combination of oxidative reaction and the formation of coordination complexes. The proposed electrospinning and cross-linking strategy is easy, of low cost, and scalable and uses non-toxic solvents as well as biocompatible and biofunctional molecules. Furthermore, thanks to the chelation capacity of tannic acid having the ability to coordinate with a wide variety of metals, hybrid smart nanowebs can be envisaged for diverse applications such as biomedical, catalysis as well as environment.
Published: 2018
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45. Studying Electrocatalyts in Operando Conditions: Correlating TEM Imaging and X-Ray Spectroscopies

Author: Dris Ihiawakrim, Ovidiu Ersen, David Portehault, Sophie Carenco, Clément Sanchez, Nathaly Ortiz Peña, and Christel Laberty-Robert
Subjects: Materials science, X-ray, Analytical chemistry, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 0210 nano-technology, 01 natural sciences, Instrumentation, 0104 chemical sciences
Published: 2019
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46. Three-Dimensional Tomographic Analyses of CeO2 Nanoparticles

Author: Dris Ihiawakrim, Cédric Feral-Martin, Jérôme Majimel, Ovidiu Ersen, Ileana Florea, Charles Hirlimann, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB)
Subjects: Surface (mathematics), Materials science, business.industry, Solvothermal synthesis, Nanoparticle, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Dark field microscopy, Molecular physics, 0104 chemical sciences, Optics, Electron tomography, Octahedron, Transmission electron microscopy, General Materials Science, Nanorod, 0210 nano-technology, business
Abstract: International audience; A detailed morphological and structural analysis of CeO2 nanoparticles has been performed using electron tomography in scanning transmission mode in high angle annular dark field. The nanoparticles have been prepared through a solvothermal synthesis assisted by microwave heating. An adequate choice of the synthesis parameters leads to particles with various well-defined morphologies: cubes, octahedrons, and nanorods. In the case of cubic CeO2 nanoparticles, the three-dimensional analysis allowed us to precisely calculate the type and the proportion of the minor facets exposed at the nanoparticle surface. For the CeO2 nanoparticles with an octahedron shape, it has been demonstrated that the ambiguous interpretation of the objects giving triangular views in classical transmission electron microscopy can be prevented; furthermore, precise assignments of their external shape, surface crystallography, and type of minor facets were realized. In the case of nanorods, it was shown that the external shape and the transversal symmetry are strongly dependent on the nanorod sizes. The presence of a well-defined porosity inside the rods was also evidenced thanks to the ability of the electron tomography to solve the internal structure of a nano-object.
Published: 2013
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47. Synthesis engineering of iron oxide raspberry-shaped nanostructures

Author: Simona Moldovan, D. Begin, Ovidiu Ersen, Sylvie Begin-Colin, Sébastien Lemonnier, Elodie Barraud, Dris Ihiawakrim, Olivier Gerber, Benoit P. Pichon, Ileana Florea, Jean-Marc Greneche, Institut de biologie et chimie des protéines [Lyon] (IBCP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut des Molécules et Matériaux du Mans (IMMM), Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut franco-allemand de recherches de Saint-Louis (ISL), DGA-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Materials science, Nanostructure, Iron oxide, Nanoparticle, Nanotechnology, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Nanocrystal, Phase (matter), Alkoxide, General Materials Science, Lamellar structure, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Magnetite
Abstract: Magnetic porous nanostructures consisting of oriented aggregates of iron oxide nanocrystals display very interesting properties such as a lower oxidation state of magnetite, and enhanced saturation magnetization in comparison with individual nanoparticles of similar sizes and porosity. However, the formation mechanism of these promising nanostructures is not well understood, which hampers the fine tuning of their magnetic properties, for instance by doping them with other elements. Therefore the formation mechanism of porous raspberry shaped nanostructures (RSNs) synthesized by a one-pot polyol solvothermal method has been investigated in detail from the early stages by using a wide panel of characterization techniques, and especially by performing original in situ HR-TEM studies in temperature. A time-resolved study showed the intermediate formation of an amorphous iron alkoxide phase with a plate-like lamellar structure (PLS). Then, the fine investigation of PLS transformation upon heating up to 500 °C confirmed that the synthesis of RSNs involves two iron precursors: the starting one (hydrated iron chlorides) and the in situ formed iron alkoxide precursor which decomposes with time and heating and contributes to the growth step of nanostructures. Such an understanding of the formation mechanism of RSNs is necessary to envision efficient and rational enhancement of their magnetic properties.
Published: 2017
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48. Structural, optical, and magnetic properties of polycrystalline Co-doped TiO2 synthesized by solid-state method

Author: Dris Ihiawakrim, A. Derory, Abdelhamid Bouaine, and Guy Schmerber
Subjects: Materials science, Band gap, Mechanical Engineering, Doping, Aucun, Analytical chemistry, Physics::Optics, Magnetic semiconductor, Condensed Matter Physics, Condensed Matter::Materials Science, Tetragonal crystal system, Magnetization, Paramagnetism, Ferromagnetism, Mechanics of Materials, Condensed Matter::Superconductivity, Physics::Atomic and Molecular Clusters, Condensed Matter::Strongly Correlated Electrons, General Materials Science, Crystallite
Abstract: We have used a solid-state method to synthesize polycrystalline Co-doped TiO 2 diluted magnetic semiconductors (DMSs) with Co concentrations of 0, and 0.5 at.%. X-ray diffraction patterns reveal that Co doped TiO 2 crystallizes in the rutile tetragonal structure with no additional peaks. Transmission electron microscopy (TEM) did not indicate the presence of magnetic parasitic phases and confirmed that Co ions are uniformly distributed inside the samples. Optical absorbance measurements showed an energy band gap which decreases after doping with the Co atoms into the TiO 2 matrix. Magnetization measurements revealed a paramagnetic behavior for the as-prepared Co-doped TiO 2 and a ferromagnetic behavior for the same samples after annealed under a mixture of H 2 /N 2 atmosphere.
Published: 2012
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49. 3D Analysis of the Morphology and Spatial Distribution of Nitrogen in Nitrogen-Doped Carbon Nanotubes by Energy-Filtered Transmission Electron Microscopy Tomography

Author: Ovidiu Ersen, Dris Ihiawakrim, Cédric Messaoudi, Kambiz Chizari, Raul Arenal, Ileana Florea, Izabela Janowska, and Cuong Pham-Huu
Subjects: Analytical chemistry, chemistry.chemical_element, General Chemistry, Iterative reconstruction, Carbon nanotube, Biochemistry, Nitrogen, Catalysis, law.invention, Condensed Matter::Materials Science, Colloid and Surface Chemistry, chemistry, Transmission electron microscopy, law, Ionization, Energy filtered transmission electron microscopy, Tomography, Carbon
Abstract: We present here the application of the energy-filtered transmission electron microscopy (EFTEM) in the tomographic mode to determine the precise 3D distribution of nitrogen within nitrogen-doped carbon nanotubes (N-CNTs). Several tilt series of energy-filtered images were acquired on the K ionization edges of carbon and nitrogen on a multiwalled N-CNT containing a high amount of nitrogen. Two tilt series of carbon and nitrogen 2D maps were then calculated from the corresponding energy-filtered images by using a proper extraction procedure of the chemical signals. Applying iterative reconstruction algorithms provided two spatially correlated C and N elemental-selective volumes, which were then simultaneously analyzed with the shape-sensitive reconstruction deduced from Zero-Loss recordings. With respect to the previous findings, crucial information obtained by analyzing the 3D chemical maps was that, among the two different kind of arches formed in these nanotubes (transversal or rounded ones depending on their morphology), the transversal arches contain more nitrogen than do the round ones. In addition, a detailed analysis of the shape-sensitive volume allowed the observation of an unexpected change in morphology along the tube axis: close to the round arches (with less N), the tube is roughly cylindrical, whereas near the transversal ones (with more N), its shape changes to a prism. This relatively new technique is very powerful in the material science because it combines the ability of the classical electron tomography to solve 3D structures and the chemical selectivity of the EFTEM imaging.
Published: 2012
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50. Hexahistidine-Tagged Single-Walled Carbon Nanotubes (His6-tagSWNTs): A Multifunctional Hard Template for Hierarchical Directed Self-Assembly and Nanocomposite Construction

Author: Dris Ihiawakrim, Rachid Baati, Céline Dietlin, Rodrigue R. Mafouana, Guy Duportail, and Ovidiu Ersen
Subjects: Materials science, Nanocomposite, Supramolecular chemistry, Rational design, Stacking, Nanotechnology, Carbon nanotube, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, law.invention, Biomaterials, Nanoelectronics, law, Electrochemistry, Surface modification, Self-assembly
Abstract: While a hexahistidine affinity tag can be introduced at protein termini or internal sites by standard molecular biology procedures for purification, immobilization, or labeling of proteins, here the versatility of this concept is exploited for the chemical preparation of novel hexahistidine-tagged single-walled carbon nanotubes (His6-tagSWNTs), a novel hard template useful for solubilizing, assembling, processing, and interfacing SWNTs in aqueous conditions. Water-soluble and exfoliated His6-tagSWNTs are prepared and fully characterized. This functional molecular module is able to interact via robust physisorption (π−π stacking) with the sidewall of SWNTs and combines the versatility of small, water-soluble reporters (His6) for hierarchical directed self-assembly (HDSA) and construction of nanocomposites. It is demonstrated that metal coordination bonds with Ni(II) can be used for the supramolecular self assembly of His6-tagSWNTs, generating complex reticulated networks and architectures. The His6-tagSWNTs hard template nanohybrid is further utilized for directed self-assembly with silica nanoparticles. The versatility of the novel hybrids opens a new era for the rational design, smart (bio)functionalization, processing, interfacing, and self assembling of carbon nanotubes for the construction of multicomposites and more complex systems with controllable spatial organization and programmable properties for a wide range of applications in biology, nanoelectronics, and catalysis.
Published: 2012
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