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1. Straightforward preparation of supramolecular Janus nanorods by hydrogen bonding of end-functionalized polymers

Author: Shuaiyuan Han, Sandrine Pensec, Dijwar Yilmaz, Cédric Lorthioir, Jacques Jestin, Jean-Michel Guigner, Frédérick Niepceron, Jutta Rieger, François Stoffelbach, Erwan Nicol, Olivier Colombani, and Laurent Bouteiller
Subjects: Science
Abstract: Janus cylinders are useful as building blocks for advanced functional materials but challenging to prepare. Here, the authors describe a robust strategy to form micrometer long Janus nanorods by self-assembly in water of end-functionalized polymers.
Published: 2020
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2. Tunable Multiscale Nanoparticle Ordering by Polymer Crystallization

Author: Dan Zhao, Vianney Gimenez-Pinto, Andrew M. Jimenez, Longxi Zhao, Jacques Jestin, Sanat K. Kumar, Brooke Kuei, Enrique D. Gomez, Aditya Shanker Prasad, Linda S. Schadler, Mohammad M. Khani, and Brian C. Benicewicz
Subjects: Chemistry, QD1-999
Published: 2017
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3. Author Correction: Straightforward preparation of supramolecular Janus nanorods by hydrogen bonding of end-functionalized polymers

Author: Shuaiyuan Han, Sandrine Pensec, Dijwar Yilmaz, Cédric Lorthioir, Jacques Jestin, Jean-Michel Guigner, Frédérick Niepceron, Jutta Rieger, François Stoffelbach, Erwan Nicol, Olivier Colombani, and Laurent Bouteiller
Subjects: Science
Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Published: 2020
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4. Aluminum-induced colloidal destabilization of iron-organic matter nanoaggregates

Author: Anthony Beauvois, Delphine Vantelon, Jacques Jestin, Aurélien Dupont, Valérie Briois, Erwan Paineau, Thomas Bizien, Alice Pradel, Mélanie Davranche, Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), LLB - Matière molle et biophysique (MMB), 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), Biosit : biologie, santé, innovation technologique (SFR UMS CNRS 3480 - INSERM 018), Université de Rennes (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Laboratoire de Physique des Solides (LPS), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), INSU : Initiative Structurante EC2CO – BIOHEFECT, and Dubigeon, Isabelle
Subjects: XAS, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Geochemistry and Petrology, aluminum, [SDU.STU.GC] Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Ferrihydrite, humic acid, SAXS
Abstract: International audience; The structural organization of heterogeneous and multiphase natural aggregates depends on the biophysicochemical conditions prevailing in the environment, with major ions playing a crucial role. In this study, the impact of aluminum (Al) on iron-organic matter (Fe-OM) aggregates was investigated since Al can interact with OM and can be incorporated in Fe-oxyhydroxides or adsorbed on their surface. Mimetic environmental Fe-OM-Al aggregates were synthesized at various [Fe] and [Al] with a constant [OM]. At low [Al+Fe], Fe-OM-Al aggregates exhibit a colloidal behavior. Within the aggregates, Fe is present as Fe(III)-oligomers and ferrihydrite-like nanoparticles whereas Al forms monomers, oligomers and small polymers, all bound to OM. The Al and Fe phases interacted with each other. At high [Fe+Al], the Fe(III)-oligomers and Al monomers/oligomers polymerized which increases the size and quantity of the ferrihydrite-like nanoparticles and Al polymers and then branched out the OM, resulting in a large settling network. The effect of Al on the Fe-OM aggregates structure could also have an impact on the fate of pollutants. The occurrence of Al amorphous hydroxides and the increase in ferrihydrite-like nanoparticles lead to a higher availability of surface reactive sites and subsequently to an increase in the sorption capacity of the Fe-OM aggregates for pollutants that exhibit a greater affinity for minerals than for organics.
Published: 2023
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5. Exchange Lifetimes of the Bound Polymer Layer on Silica Nanoparticles

Author: Kyle Misquitta, Jacques Jestin, Andrew Jimenez, Sanat K. Kumar, Dan Zhao, Department of Chemical Engineering [Columbia], University of Missouri [Columbia] (Mizzou), University of Missouri System-University of Missouri System, LLB - Matière molle et biophysique (MMB), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, and 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)
Subjects: chemistry.chemical_classification, [PHYS]Physics [physics], Materials science, Polymers and Plastics, Polymer nanocomposite, Organic Chemistry, Nanoparticle, 02 engineering and technology, Polymer, Atmospheric temperature range, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Small-angle neutron scattering, 0104 chemical sciences, Inorganic Chemistry, Silica nanoparticles, chemistry, Chemical engineering, Desorption, Materials Chemistry, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Layer (electronics), [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
Abstract: International audience; Understanding the structure and dynamics of the bound polymer layer (BL) that forms on favorably interacting nanoparticles (NPs) is critical to revealing the mechanisms responsible for material property enhancements in polymer nanocomposites (PNCs). Here we use small angle neutron scattering to probe the temporal persistence of this BL in the canonical case of poly(2-vinylpyridine) (P2VP) mixed with silica NPs at two representative temperatures. We have observed almost no long-term reorganization at 150 °C (∼Tg,P2VP + 50 °C), but a notable reduction in the BL thickness at 175 °C. We believe that this apparently strong temperature dependence arises from the polyvalency of the binding of a single P2VP chain to a NP. Thus, while the adsorption–desorption process of a single segment is an activated process that occurs over a broad temperature range, the cooperative nature of requiring multiple segments to desorb converts this into a process that occurs over a seemingly narrow temperature range.
Published: 2022
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6. Self-Assembly of Monodisperse versus Bidisperse Polymer-Grafted Nanoparticles

Author: Dan Zhao, Mohammad M. Khani, Jacques Jestin, Matteo Di Nicola, Sanat K. Kumar, and Brian C. Benicewicz
Subjects: chemistry.chemical_classification, Materials science, Polymers and Plastics, Organic Chemistry, Dispersity, Nanoparticle, 02 engineering and technology, Polymer, 010402 general chemistry, 021001 nanoscience & nanotechnology, Grafting, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, Silica nanoparticles, chemistry.chemical_compound, chemistry, Chemical engineering, Materials Chemistry, Polystyrene, Self-assembly, Composite material, 0210 nano-technology, Dispersion (chemistry)
Abstract: We systematically compare the dispersion and self-assembly of silica nanoparticles (NPs) grafted with either a sparse monomodal long chain length polystyrene (PS) brush or a bimodal brush comprised of a sparse grafting of long PS chains and a dense carpet of short poly(2-vinylpyridine) (P2VP) chains. These two different types of NPs are placed in pure PS matrices of varying molecular weights in a series of experiments. We first show that NP dispersion is generally improved in the case of bimodal brushes. More interestingly, at low PS grafting densities the bimodal brushes give different self-assembled structures relative to the monomodal brushes; we conjecture that the presence of the short P2VP chains in the bimodal brush reduces the effective core-core attractions and thus allows these bidisperse NPs to display self-assembly behavior that is less likely to be kinetically trapped by the strong intercore attractions that control the behavior of monomodal NPs. In this low PS grafting density limit, where we expect the spatial coverage of the brush to be the most nonuniform, we find the formation of "vesicular" structures that are representative of highly asymmetric ("tadpole") surfactants. Our results therefore show that reducing the inter-NP attractions gives rise to a much richer ensemble of NP self-assemblies, apparently with a smaller influence from kinetic traps (or barriers).
Published: 2022

7. Probing Multiscale Structure of Mineral and Nanoporous Kerogen Phase in Organic-Rich Source Rocks: Quantitative Comparison of Small-Angle X-ray and Neutron Scattering

Author: Loïc Barré, Jacques Jestin, Pierre Levitz, Eric Kohler, Gaël J. Cherfallot, and Pauline Michel
Subjects: Mineral, Materials science, Nanoporous, General Chemical Engineering, X-ray, Energy Engineering and Power Technology, Mineralogy, 02 engineering and technology, Neutron scattering, 021001 nanoscience & nanotechnology, chemistry.chemical_compound, Fuel Technology, 020401 chemical engineering, chemistry, Source rock, 13. Climate action, Greenhouse gas, Phase (matter), Kerogen, 0204 chemical engineering, 0210 nano-technology
Abstract: Source rocks are expected to become increasingly important in the upcoming years for oil and gas production as well as for the storage of greenhouse gases. These rocks are bedded and heterogeneous ...
Published: 2020
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8. Tailoring the Proton Conductivity and Microstructure of Block Copolymers by Countercation-Selective Membrane Fabrication

Author: Thi Khanh Ly Nguyen, Huu-Dat Nguyen, Cristina Iojoiu, Jacques Jestin, Emilie Planes, Lionel Porcar, Sandrine Lyonnard, Matériaux Interfaces ELectrochimie (MIEL), Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces (LEPMI), Institut de Chimie du CNRS (INC)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Genèse et Usage d'Interfaces Durables pour l'Energie (GUIDE), LLB - Matière molle et biophysique (MMB), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Institut Laue-Langevin (ILL), ILL, Synthèse, Structure et Propriétés de Matériaux Fonctionnels (STEP ), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Département Interfaces pour l'énergie, la Santé et l'Environnement (DIESE), 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and ANR-16-CE05-0016,NSPEM,Ionomères et membranes nanostructurés avec architectures controlées pour les PEMFC(2016)
Subjects: Materials science, Fabrication, Proton, 02 engineering and technology, Counter cation, Conductivity, 010402 general chemistry, Membrane morphology, 01 natural sciences, 7. Clean energy, enhance membrane conductivity, perfluorosulfonic acid, Copolymer, Physical and Theoretical Chemistry, Lewis acid strength, SANS, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Microstructure, Casting, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, block copolymers, General Energy, Membrane, Chemical engineering, membrane morphology control, polymer electrolyte, 0210 nano-technology
Abstract: International audience; Here we report a simple-but-effective method to control the membrane morphology and transport properties of aromatic multi-block copolymers bearing perfluorosulfonic functions, via casting with different counter-cations. Five monovalent cations with different sizes, polarity, hydrophobicity, i.e., H + , Li + , K + , Cs + , TEA + , and one double-valence cation, i.e., Ca 2+ , were selected for manufacturing block copolymer membranes. We show that the counter-cation has a strong impact on the superstructure long-range order by acting as either block-separator, either block-compatibilizer, therefore tuning the thermodynamics of the self-assembly process. Hence, by selecting the cations, highly ordered or completely disordered phase-separated block morphologies can be created. The effect of counter-cation nature on the morphology is strongly reflected on the proton conductivity of acidified membranes. At 25 °C and 10% relative humidity, the acidified TEA +-cast membranes are 22 times less conductive than the acidified Cs +-cast ones. By combining microscopy and neutron scattering techniques, we reveal the direct correlation between enhanced functional properties and quality of membrane microstructure directed by the nature of cations with beneficial characteristics. Our findings highlight the role and importance of cation selection to tailor the functional properties of multiblock ionomers applicable as solid electrolytes for energy conversion devices.
Published: 2020
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9. Controlling the morphology in epoxy/thermoplastic systems

Author: Eléonore Mathis, Marie-Laure Michon, Claude Billaud, Caroll Vergelati, Nigel Clarke, Jacques Jestin, Didier R. Long, Laboratoire Polymères et Matériaux Avancés (LPMA), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), SOLVAY Res & Innovat Ctr Lyon, Solvay S.A., Solvay (France), Solvay Composite Materials (SCM), Department of Physics and Astronomy [Sheffield], University of Sheffield [Sheffield], Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), LLB - Matière molle et biophysique (MMB), 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), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], [CHIM.POLY]Chemical Sciences/Polymers, Polymers and Plastics, Process Chemistry and Technology, Organic Chemistry
Abstract: International audience; Thermosets are frequently toughened by a high-T g thermoplastic (TP). Blend morphologies, obtained by curing induced phase separation with scales of a few hundreds of nanometers are relevant for highperformance applications, but no quantitative description for obtaining these morphologies exist yet. We propose such a quantitative approach for predicting and controlling the final morphology. The key is the degree of curing and the corresponding T g of the blend and of both phases when phase separation takes place. It is controlled by the Flory interaction parameter  of the constituents and their respective T g 's. We show that if phase separation takes place too early during curing, the T g is too low and morphologies grow to reach sizes of a few micrometers, or more. Our study of different systems allows us to propose the relevant range of Flory interaction parameter  and temperature window T-T g for which the sizes of interest may be obtained. Our work opens the way for devising thermoplasticsthermosets couples with the appropriate affinity and T g s in order to make blends with tailored morphologies.
Published: 2022
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10. In Situ SAXS and SANS Monitoring of Both Nanofillers and Polymer Chain Microstructure under Uniaxial Stretching in a Nanocomposite with a Controlled Anisotropic Structure

Author: Anne-Sophie Robbes, Jacques Jestin, Florian Meneau, Florent Dalmas, François Boué, Fabrice Cousin, Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), LLB - Matière molle et biophysique (MMB), 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), Laboratório Nacional de Luz Sìncrotron (LNLS), Centro Nacional de Pesquisa em Energia e Materiais = Brazilian Center for Research in Energy and Materials (CNPEM), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Inorganic Chemistry, Polymers and Plastics, [PHYS.PHYS]Physics [physics]/Physics [physics], Organic Chemistry, Materials Chemistry
Abstract: International audience; We present a combined detailed monitoring of the respective evolutions of the structure of fillers by SAXS and conformation of polymeric chains by SANS under uniaxial stretching at various elongation ratios in a nanocomposite made of spherical magnetic nanoparticles of γFe2O3 dispersed in a matrix of polystyrene (PS) chains. We can make the structure of fillers in the nanocomposite before stretching very anisotropic, as we demonstrated in reference (Macromolecules,2011,44(22), 8858–8865), thanks to the appliance of a magnetic field during the nanocomposite processing that induces the formation of nanoparticle chains aligned along the direction of the field, either parallel or perpendicular to the subsequent stretching. This gives rise to very anisotropic mechanical properties, and the structure of fillers evolves very differently. In the parallel case, there is a rupture of the chains of nanoparticles into smaller subunits that progressively align completely in the stretching direction. In the perpendicular case, the chains first rotate, to eventually reorient along the stretching direction, gradually breaking themselves. Finally, at a very large elongation rate (λ = 6), the organization of nanoparticles in both cases converge toward a common structure made of small chains of nanoparticles completely oriented along the stretching. The chain conformation is directly obtained by SANS as we probed samples containing 25% PSH/75% PSD chains, taking benefit from the fact that the neutron scattering length density of PSD is similar to the one of γFe2O3. Strikingly, the deformation of the polymer chains is the same as in the reference PS matrix without fillers, whatever stretching is parallel and perpendicular to the chains of nanoparticles at λ = 3. The chains scattering exhibit the typical features of those of the former studies of relaxation during or after stretching on pure melts, accounting for the relatively slow deformation rate, the distance from Tg (15 °C) their average masses, and their large polydispersity.
Published: 2022
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11. How does calcium drive the structural organization of iron–organic matter aggregates? A multiscale investigation

Author: Marie-Sousai Appavou, Camille Rivard, Andrea Sorrentino, Delphine Vantelon, Elaheh Lotfi-Kalahroodi, Anthony Beauvois, Anne-Catherine Pierson-Wickmann, Martine Bouhnik-Le Coz, Jacques Jestin, Thomas Bizien, Baohu Wu, Valérie Briois, Aurélien Dupont, Mélanie Davranche, Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), LLB - Matière molle et biophysique (MMB), Laboratoire Léon Brillouin (LLB - UMR 12), 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), European Synchrotron Radiation Facility (ESRF), Département Caractérisation et Elaboration des Produits Issus de l'Agriculture (CEPIA), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Biosit : biologie, santé, innovation technologique (SFR UMS CNRS 3480 - INSERM 018), Université de Rennes (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), ALBA Synchrotron light source [Barcelone], Forschungszentrum Julich, Outstn MLZ, JCNS, D-85747 Garching, Germany, ORPHREA - ARED, Région Bretagne, 'ISAAP' project, Institut national des sciences de l'Univers, ANR-10-EQPX-45, Agence Nationale de la Recherche, ANR-10-EQPX-0045,ROCK,Spectromètre EXAFS Rapide pour Cinétiques Chimiques(2010), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS)
Subjects: chemistry.chemical_classification, Total organic carbon, 010504 meteorology & atmospheric sciences, Absorption spectroscopy, Materials Science (miscellaneous), Dimer, chemistry.chemical_element, 010501 environmental sciences, Calcium, 01 natural sciences, chemistry.chemical_compound, Ferrihydrite, chemistry, Chemical engineering, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, 13. Climate action, ddc:333.7, Leonardite, Humic acid, Organic matter, 0105 earth and related environmental sciences, General Environmental Science
Abstract: International audience; Iron-organic matter (Fe-OM) aggregates are a key factor in the control of pollutant mobility. Their physical and structural organization depends on the prevailing physicochemical conditions during their formation and on subsequent exposure to variations in porewater goechemistry. Among these conditions, calcium (Ca) could be a major parameter given its high concentrations in the environment and its affinity for OM. Mimetic environmental Fe-OM-Ca associations were synthesized at various Fe/organic carbon (OC) and Ca/Fe molar ratios using Leonardite humic acid as OM model. The impact of Ca on Fe-OM aggregates was studied by a combination of X-ray absorption spectroscopy, small angle X-ray and neutron scattering and imaging techniques (TEM, cryo-TEM and cryo-TXM). Iron phases are constituted of Fe(III)-oligomers, Fe(III)-nanoparticles and ferrihydrite (Fh), all bound or embedded by OM. Iron phases exhibit a fractal organization with Fe-primary beads aggregated as Fe-primary aggregates (Fe-PA) which themselves are embedded in an OM aggregates. For Ca/OC (mol/mol) < 0.026, Fe-PA aggregate in a third level as a Fe-secondary aggregate. For Ca/OC ≥ 0.026, OM forms a large Ca-branched network in which Ca is bound as a dimer to OM carboxylic sites. In such conditions, Fe-PA are distributed in the OM network, distant from each other. All these structural transitions are driven by Ca which partially screens the Fe-OM interactions. The formation of such micrometric network should impact both the surface reactivity of the Fe phases as well as the mobility of Fe, OM and associated elements, notably in the soil porosity where they are produced under natural conditions.
Published: 2020
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12. Temperature dependent self-organization of DMPC membranes promoted by intermediate amounts of the saponin aescin

Author: Yvonne Hannappel, Thomas Hellweg, Jacques Jestin, Rajeev Dattani, Oliver Wrede, Carina Dargel, Sylvain Prévost, Ramsia Sreij, Physical and Biophysical Chemistry (PC III), Department of Chemistry, Universität Bielefeld-Universität Bielefeld, LLB - Matière molle et biophysique (MMB), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, European Synchrotron Radiation Facility (ESRF), Institut Laue-Langevin (ILL), ILL, and 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)
Subjects: [SDV]Life Sciences [q-bio], Biophysics, Phospholipid, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Biochemistry, chemistry.chemical_compound, Microscopy, Electron, Transmission, X-Ray Diffraction, Phase (matter), Scattering, Small Angle, [CHIM]Chemical Sciences, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], [PHYS]Physics [physics], Aescin, Escin, Small-angle X-ray scattering, Bilayer, Vesicle, Membranes, Artificial, Cell Biology, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Membrane, chemistry, Transmission electron microscopy, Dimyristoylphosphatidylcholine, 0210 nano-technology
Abstract: International audience; The plant-derived biosurfactant aescin is naturally present in many plants and is used for treatment of disorders such as varicose veins and inflammation of veins. The hemolytic activity of this saponin is attributed to its interaction with cholesterol in the red blood cell membrane. This work investigates the phase and aggregation behavior of saponin-containing model membranes consisting of the phospholipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). The aescin concentrations studied range from 1 mol% to 7 mol% with respect to the total lipid content. The methods of choice to elucidate the structural picture are small-angle scattering of X-rays (SAXS) and neutrons (SANS) and cryogenic transmission electron microscopy (cryo-TEM). SANS and SAXS revealed that at lower aescin contents vesicular structures are conserved and vesicles tend to aggregate already at aescin contents of around 1 mol%. Aggregation and vesicle deformation effects are found to be stronger when the phospholipids are in the L phase. With increasing aescin content, mixed structures, i.e. aggregated and deformed vesicles and solubilized bilayer fragments, are present. This was proven for a sample with 4 mol% aescin by cryo-TEM. An increasing aescin amount leads to membrane decomposition and free standing bilayers which tend to build stacks at high temperature. These stacks are characterized by SAXS using the modified Caillé theory. Analyses and model dependent fitting reveal formation of well-defined structures beginning at 7 mol% aescin.
Published: 2019
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13. Al and Si oxyanions impact on the structural organization of Fe-OM nanoaggregates

Author: Delphine Vantelon, Jacques Jestin, Anthony Beauvois, Mélanie Davranche, Synchrotron SOLEIL (SSOLEIL), 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), Géosciences Rennes (GR), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Structural organization, Materials science, Chemical engineering, 13. Climate action, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry
Abstract: International audience; Natural colloids composed of iron (Fe) and organic matter (OM) are a key factor controlling the mobility of metallic pollutants due to their high adsorption capacity, a consequence of their high density of binding sites. The physico-chemical conditions under which Fe-OM nano-aggregates are formed influence their structural organization, and more particularly the speciation of Fe. In this study, we probe the influence of two major elements of natural systems: aluminum (Al) and silicon (Si). Al is known to have a high affinity with OM but also easily enters the structure of Fe hydroxides. Si, on the other hand, is known to inhibit the growth and crystallinity of Fe hydroxides, although the mechanisms remain unknown. Al and Si are therefore expected to influence the Fe-OM nano-aggregates organization and to have an impact on the Fe speciation.Fe-OM-Al/Si nano-aggregates, mimicking environmental ones, have been synthesized with different Fe/OM and oxyanion/Fe ratios. In these systems, the Fe speciation is complex and variable, depending on the Fe and oxyanion content relative to OM. The Fe phases appear to be composed of oligomers and ferrihydrite-like nanoparticles (Fh-Np), both integrated in the OM matrix. The Fh-Np form a fractal network whose organization is controlled by the OM. As Fe/OM increases, the oligomer content decreases in favor of the Fh-Np, which increases in size. By adding Al or Si, this phenomenon may strongly differ. Al, forming oligomers and bound to both Fe and OM, clearly allows the growth of the Fh-Np/oligomer ratio, the Fh-Np size and the whole nano-aggregates structure. On the contrary, Si, bound to Fe, has the exact opposite effect. These differences result from the different interactions between Al and Si and the components of the Fe-OM nano-aggregates.These results clearly highlight the antagonist effect of the major elements, Al and Si, on the structural organization of Fe-OM colloids. They impact all the levels of organization: the Fe speciation and the OM and Fh-Np arrangement. This structural variability has a direct consequence on the ability of Fe-OM nano-aggregates to trap and transport pollutants in the hydrographic network.
Published: 2021
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14. Coaxial electrospinning process toward optimal nanoparticle dispersion in polymeric matrix

Author: Luc Lenglet, Christopher Y. Leon-Valdivieso, Francisco Sebastian Navarro Oliva, Alejandro Ospina, Fahmi Bedoui, Léo Picart, Jacques Jestin, Ahmed Benalla, Roberval (Roberval), Université de Technologie de Compiègne (UTC), Normafin, Institut Laue-Langevin (ILL), and ILL
Subjects: Fabrication, Materials science, Polymers and Plastics, Nanoparticle, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, dispersions, Materials Chemistry, polymer nanofiber, Fiber, Composite material, electrospinning, chemistry.chemical_classification, [PHYS]Physics [physics], General Chemistry, Polymer, 021001 nanoscience & nanotechnology, Polyvinylidene fluoride, Electrospinning, 0104 chemical sciences, Polymer Composites nanoparticles, chemistry, Chemical engineering, Nanofiber, Ceramics and Composites, 0210 nano-technology, Dispersion (chemistry)
Abstract: International audience; Nano-reinforced polymers have gained popularity in the last decades since they exhibit enhanced properties (compared to pristine polymers) that are useful in a wide range of applications. Unfortunately, dispersion of nanoparticles (NP) into polymeric matrices is a major problem since they tend to form agglomerates, limiting the improvement of properties and further applications. In this work, we propose the use of coaxial electrospinning as onestep method to disperse nanoparticles in a polymeric matrix. Particularly, iron oxide (Fe 3 O 4) NP with a monomodal and bimodal size distributions were dispersed in polyvinylidene fluoride (PVDF), a material that is well-known for its improved piezoelectric properties when it is processed via electrospinning. The results indicate that the incorporation of NP modified the polymeric fiber depending on their surface-to-volume ratio (smaller NP promoted smaller fiber size). Moreover, TEM revealed a good NP dispersion in the polymer, especially for the smallest NP size (monomodal). Finally, each NP size distributions were well preserved in the electrospun mats compared to the initial NP solutions, demonstrating the suitability of this technique for the fabrication of nano-reinforced PVDF structures with tailored NP size. Overall, this method could represent a facile and practical alternative to fabricate materials with piezoelectric/super-paramagnetic properties.
Published: 2021
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15. Morphological changes of silica aged under environmental conditions by three-dimensional nanoscale quantifications

Author: Guilhem P. Baeza, Karine Masenelli-Varlot, Jacques Jestin, Geneviève Foray, Lucian Roiban, Bernard Yrieix, Bruno Chal, Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), ILL, Matériaux et Mécanique des Composants (EDF R&D MMC), EDF R&D (EDF R&D), and EDF (EDF)-EDF (EDF)
Subjects: Length scale, Superinsulation, Nanostructure, Materials science, Renewable Energy, Sustainability and the Environment, Nanotechnology, 02 engineering and technology, General Chemistry, Energy consumption, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 7. Clean energy, 0104 chemical sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Thermal conductivity, Electron tomography, Natural rubber, visual_art, visual_art.visual_art_medium, General Materials Science, 0210 nano-technology, Nanoscopic scale
Abstract: In recent decades, nanostructured silica has become a key component in several materials developed at the industrial length scale. Used for its outstanding ability to structure food, drugs, and rubber, to fulfil specific needs in numerous applications, it has also led to the widespread development of sustainable energy-based materials. Superinsulation materials endowed with an exceptionally low thermal conductivity are a major goal regarding energy consumption and carbon dioxide emission. However, because the properties of insulation materials greatly depend on their nanostructures, it is crucial to ensure their hygrothermal stability, by limiting ageing phenomena. Here, we thoroughly characterize the hygrothermal ageing of a fractal industrially relevant silica using a complementary set of experimental techniques, providing local (TEM and electron tomography) and statistical indicators of structural evolution. For the first time, we unambiguously evidence the smoothing of elementary particles and quantify their growth (from 4.3 to 10.0 nm), which results in the densification of aggregates at the upper length scale.
Published: 2021
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16. Impact of the protein composition on the structure and viscoelasticity of polymer-like gluten gels

Author: Paul Menut, Zhendong Fu, Jacques Jestin, Marie-Sousai Appavou, Ameur Louhichi, Laurence Ramos, Justine Pincemaille, Marie-Hélène Morel, Amélie Banc, Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Ingénierie des Agro-polymères et Technologies Émergentes (UMR IATE), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association, Paris-Saclay Food and Bioproduct Engineering (SayFood), AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ANR-18-CE06-0012,ELASTOBIO,Gels élastomériques de biopolymères soumis à des déformations extrêmes(2018), ANR-10-LABX-0020,NUMEV,Digital and Hardware Solutions and Modeling for the Environement and Life Sciences(2010), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), LLB - Matière molle et biophysique (MMB), and 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)
Subjects: Glutens, Polymers, FOS: Physical sciences, 02 engineering and technology, Condensed Matter - Soft Condensed Matter, Neutron scattering, 01 natural sciences, Gliadin, Viscoelasticity, chemistry.chemical_compound, 0103 physical sciences, General Materials Science, ddc:530, 010306 general physics, chemistry.chemical_classification, Viscosity, Scattering, Proteins, Polymer, Protein composition, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Gluten, Solvent, Monomer, chemistry, Chemical engineering, Soft Condensed Matter (cond-mat.soft), 0210 nano-technology, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft], Gels
Abstract: We investigate the structure of gluten polymer-like gels in a binary mixture of water/ethanol, $50/50$ v/v, a good solvent for gluten proteins. Gluten comprises two main families of proteins, monomeric gliadins and polymer glutenins. In the semi-dilute regime, scattering experiments highlight two classes of behavior, akin to standard polymer solution and polymer gel, depending on the protein composition. We demonstrate that these two classes are encoded in the structural features of the proteins in very dilute solution, and are correlated with the presence of proteins assemblies of typical size tens of nanometers. The assemblies only exist when the protein mixture is sufficiently enriched in glutenins. They are found directly associated to the presence in the gel of domains enriched in non-exchangeable H-bonds and of size comparable to that of the protein assemblies. The domains are probed in neutron scattering experiments thanks to their unique contrast. We show that the sample visco-elasticity is also directly correlated to the quantity of domains enriched in H-bonds, showing the key role of H-bonds in ruling the visco-elasticity of polymer gluten gels., accepted for publication in Journal of Physics: Condensed Matter, Special issue on "Glasses and gels: a crossroad of molecular liquids, polymers and colloids"
Published: 2021
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17. How crucial is the impact of calcium on the reactivity of iron-organic matter aggregates? Insights from arsenic

Author: Martine Bouhnik-Le Coz, Jacques Jestin, Anthony Beauvois, Charlotte Catrouillet, Thomas Bizien, Valérie Briois, Delphine Vantelon, Mélanie Davranche, Géosciences Rennes (GR), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, French administrative region of Brittany, France, SOLEIL synchrotron-LLB, France, 'Institut national des sciences de l′Univers' (INSU), France, ANR-10-EQPX-45, French National Research Agency (ANR), France, ANR-10-EQPX-0045,ROCK,Spectromètre EXAFS Rapide pour Cinétiques Chimiques(2010), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-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), Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Environmental Engineering, Health, Toxicology and Mutagenesis, 0211 other engineering and technologies, chemistry.chemical_element, 02 engineering and technology, 010501 environmental sciences, Calcium, 01 natural sciences, ferrihydrite, Metal, Ferrihydrite, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Environmental Chemistry, Organic matter, Reactivity (chemistry), Waste Management and Disposal, Arsenic, 0105 earth and related environmental sciences, chemistry.chemical_classification, 021110 strategic, defence & security studies, Sorption, SAXS, Ca interactions, Pollution, EXAFS, chemistry, Chemical engineering, 13. Climate action, Ionic strength, visual_art, visual_art.visual_art_medium, Fe-OM colloid, s adsorption isotherms, Fe-oligomers
Abstract: International audience; Environmental iron-organic matter (Fe-OM) aggregates play a major role in the dynamic of pollutants. Nowadays, there is a lack of information about the control exerted by their structural organization on their reactivity towards metal(loid)s and in particular, the impact of major ions, such as calcium. The sorption capacity of mimetic environmental Fe-OM-Ca aggregates was investigated relative to the Fe/organic carbon (OC) and Ca/Fe ratios using As as a probe. It was shown that Fe speciation is the key factor controlling the reactivity of Fe-OM-Ca aggregates regarding the high affinity of Fe(III)-oligomers towards As and the high sorption capacity of ferrihydrite-like nanoparticles. Moreover, when it occurs at high concentration, Ca competes with Fe for OM binding leading to an increase in the amount of ferrihydrite-like nanoparticles and binding site availability. As a consequence, Ca not only impacts the ionic strength but it also has a dramatic impact on the structural organization of Fe-OM aggregates at several scales of organization, resulting in an increase of their sorption capacity. In the presence of high amounts of Ca, Fe-OM-Ca aggregates could immobilize pollutants in the soil porous media as they form a micrometric network exhibiting a strong sorption capacity.
Published: 2021
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18. The desalting/salting pathway: a route to form metastable aggregates with tuneable morphologies and lifetimes

Author: Jean-François Berret, Fabrice Cousin, Sumit Mehan, Jacques Jestin, Jean-Paul Chapel, Laure Herrmann, Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Matière et Systèmes Complexes (MSC (UMR_7057)), Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre de Recherche Paul Pascal (CRPP), Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-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), Matière et Systèmes Complexes (MSC), Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and ANR-13-BS08-0015,PANORAMA,Assemblage Macromoléculaire Hors-équilibre Compréhension, Contrôle & nouvelles structures(2013)
Subjects: chemistry.chemical_classification, Aqueous solution, Chemistry, Mixing (process engineering), Salt (chemistry), Nanoparticle, FOS: Physical sciences, 02 engineering and technology, General Chemistry, Condensed Matter - Soft Condensed Matter, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electrostatics, 01 natural sciences, 0104 chemical sciences, [CHIM.POLY]Chemical Sciences/Polymers, Chemical engineering, Ionic strength, Metastability, Soft Condensed Matter (cond-mat.soft), 0210 nano-technology, Dissolution, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
Abstract: We investigate the formation/re-dissociation mechanisms of hybrid complexes made from negatively charged PAA2k coated {\gamma}-Fe2O3 nanoparticles (NP) and positively charged polycations (PDADMAC) in aqueous solution in the regime of very high ionic strength (I). When the building blocks are mixed at large ionic strength (1M NH4Cl), the electrostatic interaction is screened and complexation does not occur. If the ionic strength is then lowered down to a targeted ionic strength Itarget, there is a critical threshold Ic = 0.62 M at which complexation occurs, that is independent on the charge ratio Z and the pathway used to reduce salinity (drop-by-drop mixing or fast mixing). If salt is added back up to 1M, the transition is not reversible and persistent out-of-equilibrium aggregates are formed. The lifetimes of such aggregates depends on Itarget: the closer Itarget to Ic is, the more difficult it is to dissolve the aggregates. Such peculiar behavior is driven by the inner structure of the complexes that are formed after desalting. When Itarget is far below Ic, strong electrostatic interactions induce the formation of dense, compact and frozen aggregates. Such aggregates can only poorly reorganize further on with time, which makes their dissolution upon resalting almost reversible. Conversely, when Itarget is close to Ic more open aggregates are formed due to weaker electrostatic interactions upon desalting. System can thus rearrange with time to lower its free energy and reach more stable out-of-equilibrium states which are very difficult to dissociate back upon resalting, even at very high ionic strength., Comment: 15 pages, 6 figures
Published: 2021
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19. Adhesive Sponge Based on Supramolecular Dimer Interactions as Scaffolds for Neural Stem Cells

Author: Florence Wianny, Jacques Jestin, Watson Loh, Luanda C. Lins, Colette Dehay, Institut cellule souche et cerveau (U846 Inserm - UCBL1), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)
Subjects: Tissue Engineering, Tissue Scaffolds, Polymers and Plastics, biology, Polymers, Chemistry, Dimer, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, Supramolecular chemistry, Biocompatible Materials, Bioengineering, biology.organism_classification, Neural stem cell, Biomaterials, Sponge, chemistry.chemical_compound, Neural Stem Cells, Tissue engineering, Adhesives, Materials Chemistry, Biophysics, High surface area, Adhesive, ComputingMilieux_MISCELLANEOUS
Abstract: Improving cell-material interactions of nonadhesive scaffolds is crucial for the success of biomaterials in tissue engineering. Due to their high surface area and open pore structure, sponges are widely reported as absorbent materials for biomedical engineering. The biocompatibility and biodegradability of polysaccharide sponges, coupled with the chemical functionalities of supramolecular dimers, make them promising combinations for the development of adhesive scaffolds. Here, a supramolecular tactic based on (UPy)-modified polysaccharide associated with three-dimensional structure of sponges was developed to reach enhanced cellular adhesion. For this purpose, three approaches were examined individually in order to accomplish this goal. In the first approach, the backbone polysaccharides with noncell adhesive properties were modified via a modular tactic using UPy-dimers. Hereupon, the physical-chemical characterizations of the supramolecular sponges were performed, showing that the presence of supramolecular dimers improved their mechanical properties and induced different architectures. In addition, small-angle neutron scattering (SANS) measurements and rheology experiments revealed that the UPy-dimers into agarose backbone are able to reorganize in thinning aggregates. It is also demonstrated that the resulted UPy-agarose (AGA-UPy) motifs in surfaces can promote cell adhesion. Finally, the last approach showed the great potential for use of this novel material in bioadhesive scaffolds indicating that neural stem cells show a spreading bias in soft materials and that cell adhesion was enhanced for all UPy-modified sponges compared to the reference, i.e. unmodified sponges. Therefore, by functionalizing sponge surfaces with UPy-dimers, an adhesive supramolecular scaffold is built which opens the opportunity its use neural tissues regeneration.
Published: 2020
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20. Polymer grafting from 10-nm individual particles: proving control by neutron scattering

Author: Jacques Jestin, Julian Oberdisse, Géraldine Carrot, François Boué, and A. El Harrak
Subjects: chemistry.chemical_classification, Materials science, Atom-transfer radical-polymerization, Scattering, Dispersity, General Chemistry, Polymer, Neutron scattering, Condensed Matter Physics, Small-angle neutron scattering, Crystallography, Polymerization, Chemical engineering, chemistry, Particle
Abstract: The core-shell structure of nanoparticles (5 nm radius) of silica grafted with polymer growing from the particle ("grafting from") is characterized by small angle neutron scattering (SANS), to our knowledge for the first time. This is made possible by a good control of the colloidal dispersion at each step of the synthesis. With this aim, we have improved our chemical procedure based on atom transfer radical polymerization (ATRP), which allows a good control of kinetics and polydispersity: the reaction takes place in a polar solvent, and the reaction medium remains always crystal clear. For such small particles, in contrary to direct space imaging, SANS is appropriate for characterization of the polymer corona as well as of the silica core using contrast matching provided by mixing normal and deuterated solvent. This allows checking of the level of aggregation at the nanoscale, which is found to be limited to a few percent of the particles in the reaction batch. After an initial slight increase, it is reduced by further polymerization, while the polymer layer grows progressively. After purification, grafted silica can be characterized accurately: its scattering can be fitted by a model of a silica core containing three to five particles surrounded by a polymer shell of thickness 7 nm. This is in good agreement with chain length and grafting density (214 sites per particle) evaluated by chemical analysis; hence SANS provides quantitative insight on chemical synthesis.
Published: 2020

21. Unexpected thermo-responsiveness of bisurea-functionalized hydrophilic polymers in water

Author: Gaëlle Mellot, Jacques Jestin, Jutta Rieger, Laurent Bouteiller, François Stoffelbach, Jean-Michel Guigner, Institut Parisien de Chimie Moléculaire (IPCM), Chimie Moléculaire de Paris Centre (FR 2769), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), 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)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-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), LLB - Matière molle et biophysique (MMB), Laboratoire Léon Brillouin (LLB - UMR 12), 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), Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU), ANR-17-CE09-0031,PISAForFilms,Revêtements acryliques aqueux aux propriétés renforcées(2017), Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay
Subjects: Materials science, supramacromolecular assemblies, Supramolecular chemistry, supramolecular bottlebrushes, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Micelle, Lower critical solution temperature, Biomaterials, Hydrophobic effect, Colloid and Surface Chemistry, LCST, Thermoresponsive polymers in chromatography, Reversible addition−fragmentation chain-transfer polymerization, cloud point, cylindrical micelles, Thermoresponsive, chemistry.chemical_classification, Cloud point, Polymer, 021001 nanoscience & nanotechnology, hydrogen bonding, 6. Clean water, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, nanoDSC, bisurea, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Chemical engineering, 0210 nano-technology
Abstract: International audience; Hypothesis: Thermoresponsive polymers are important materials for various applications. However, the number of polymers that exhibit this property in the temperature range of interest remains limited. The development of novel rational design strategies through the understanding of the thermal transition’s origin is therefore of utmost importance.Experiments: Bisurea-functionalized water-soluble polymers were synthesized by RAFT polymerization. After direct dissolution in water, the supramolecular assemblies were analyzed by cryo-TEM and SANS. Their temperature-dependent water-solubility was characterized by various techniques, namely DLS, SANS, DSC, IR, to understand the origin of the temperature sensitivity.Findings: The supramolecular assemblies exhibit an unexpected temperature-dependent solubility. For instance, a cloud point of only 39 °C was measured for poly(N,N-dimethylacrylamide) assemblies. This property is not restricted to one specific polymer but is rather a general feature of bisurea-functionalized polymers that form supramacromolecular bottlebrushes in water. The results highlight the existence of two distinct transitions; the first one is a visually perceptible cloud point due to the aggregation of individual micelles, presumably driven by the hydrophobic effect. The second transition is related to the dissociation of intermolecular bisurea hydrogen bonds. Finally, we show that it is possible to widely tune the cloud point temperature through the formation of co-assemblies.
Published: 2020
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22. The dramatic variability of cations impacts on Fe speciation in Fe-OM nanoaggregates

Author: Jacques Jestin, Delphine Vantelon, Anthony Beauvois, Mélanie Davranche, Dubigeon, Isabelle, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), LLB - Matière molle et biophysique (MMB), 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), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Chemistry, Environmental chemistry, [SDU.STU.GC] Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Genetic algorithm, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, [SDU.ENVI] Sciences of the Universe [physics]/Continental interfaces, environment
Abstract: Natural colloids composed of iron (Fe) and organic matter (OM) are a key factor controlling metallic pollutants mobility according to their high adsorption capacities, consequence of their high binding sites density. The physico-chemical condition in which the Fe-OM nanoaggregates are formed influences their structural organization, and more specifically the Fe speciation. In this study, we probe the influence of three major cations, present in high quantity in natural systems: Calcium (Ca), Aluminum (Al) and Silicon (Si). Ca is known to have a huge affinity toward OM, as well as Al which also easily get into Fe hydroxides structure. For its part, Si is known to restrain Fe oxides growth and crystallinity, despite mechanisms remain unknown. Ca, Al and Si are thus expected to modify Fe-OM nanoaggregates organization and impact Fe speciation.Mimetic environmental Fe-OM-cation nanoaggregates were synthesized with different Fe/OM and cation/Fe ratios. They were observed by TEM. The Fe speciation was characterized by XAS as well as the cations interactions with the components of the Fe-OM colloids. The size and arrangement of Fe-nanoparticles were determined by SAXS. Results show that Fe speciation is complex and variable according to Fe and cation contents relative to OM. Fe phases appear to be composed of oligomers and ferrihydrite nanoparticles, both embedded in the OM matrix. The Fe-nanoparticles are forming a fractal network which organization is controlled by the OM. When the Fe/OM ratio increases, oligomers content decreases to the benefit of Fe-nanoparticles which size increases. Adding cations, this phenomenon is strongly modified, either increased, with the addition of Ca and Al, or decreased, with the addition of Si. These modifications result from the different interactions we could evidence between the cations and the different Fe-OM network components.These results clearly highlight the dramatic effect of Al, Si and Ca cations on the Fe-OM colloidal network, impacting both Fe speciation and OM organization. These structural modifications directly impact the capabilities of Fe-OM nanoaggregates to trap and transport pollutants.
Published: 2020
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23. How does Ca modify the surface reactivity of Fe-OM aggregates against Arsenic binding?

Author: Valérie Briois, Thomas Bizien, Aurélien Dupont, Charlotte Catrouillet, Camille Rivard, Anthony Beauvois, Martine Bouhnik-Le Coz, Jacques Jestin, Mélanie Davranche, and Delphine Vantelon
Subjects: Surface reactivity, Chemistry, Inorganic chemistry, chemistry.chemical_element, Arsenic
Abstract: Iron-Organic Matter (Fe-OM) aggregates produced by redox alternation in wetlands are a key factor in the control of metallic pollutants mobility. Their ability to adsorb metal(loid)s depends on the size, morphology and structural arrangement between Fe and OM phases, which are mainly controlled by the OM occurrence. The physical, chemical and morphological organization of such aggregates is influenced by the physico-chemical conditions prevailing in the environment. Calcium (Ca) is a common major ion in natural waters which exhibits high affinity for OM. It can thus modify the size and the structural organization of Fe-OM aggregates and, subsequently, their ability to bind metal(loid)s. Among metal(loids), arsenic (As) is of major importance because of its high toxicity and its high affinity towards Fe(III)-oxyhydroxides. Moreover, Fe-OM aggregates are an important factor controlling the mobility of arsenic (As) in the environment.Mimetic natural Fe-OM aggregates were synthesized at various Fe/OM and Ca/Fe ratios. After a fine characterization of the size and structural organization, Fe-OM-Ca associations were used to perform As binding sorption experiments at 2 As/Fe ratios. The suspensions were stirred during 24h and subsequently filtrated ant ultra-filtrated.Our study demonstrates that Ca strongly influences the Fe-OM aggregates physical organisation. For low Ca/Fe ratio, Fe phases exhibit a fractal organization in which Fe phases are composed of oligomers, and primary nano-aggregates (around 6 nm) which aggregate in larger Fe secondary aggregates (>200 nm). Both are embedded in the OM matrix composed of isolated molecules and OM aggregates. For high Ca/Fe ratios, OM, Fe oligomers and primary nano-aggregates form a large continuous network where Fe phases are connected by OM large molecules. With the increasing Ca/Fe ratio, the amount of Fe oligomers decreases to the benefit of larger primary nano-aggregates (increase of their geometrical radius). Ultrafiltration experiments demonstrated that DOC, Fe, Ca and As follow the same size distribution. Surprisingly, As sorption increases with the increasing size and amount of primary nano-aggregates and the formation of the large network. SAXS analyses revealed that in such network, the distance between primary nano-aggregates increases as compared to their distance in secondary aggregates. All this results suggest that, with the increasing Ca/Fe ratio, although the primary nano-aggregates size increase, their structural distance allows to rise the availability of their binding site for As.This study demonstrates that Ca not only controls the Fe-OM structural organization but also its subsequent capacity to bind toxic elements such as As. These results are of major importance since such parameter was never so clearly evidence. They show that the actual representation of the physical organisation of Fe-OM aggregates and its reactivity have to be renewed as well as the geochemical models.
Published: 2020
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24. Insight into kinetics and mechanisms of AOT vesicle adsorption on silica in unfavorable conditions

Author: Julie Wolanin, Didier Frot, Hubert Perrot, Loïc Barré, Jacques Jestin, Christine Dalmazzone, Daniela Bauer, IFP Energies nouvelles (IFPEN), LLB - Matière molle et biophysique (MMB), Laboratoire Léon Brillouin (LLB - UMR 12), 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), Laboratoire Interfaces et Systèmes Electrochimiques (LISE), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay
Subjects: neutron reflectivity, Kinetics, 02 engineering and technology, QCM-D, 010402 general chemistry, 01 natural sciences, symbols.namesake, Adsorption, Pulmonary surfactant, NaCl, Electrochemistry, [CHIM]Chemical Sciences, General Materials Science, Surfactant adsorption, AOT, Spectroscopy, vesicle, Chemistry, Vesicle, Bilayer, structural rearrangement, Surfaces and Interfaces, Quartz crystal microbalance, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Chemical engineering, Ionic strength, silica, symbols, van der Waals force, 0210 nano-technology, adsorption kinetics
Abstract: International audience; The structure of adsorbed surfactant layers at the equilibrium state has already been investigated using various experimental techniques. However, the comprehension of the formation of structural intermediates in nonequilibrium states and the resulting adsorption kinetics still remain a challenging task. The temporal characterization of these intermediate structures provides further understanding of the layer structure at equilibrium and of the main interactions involved in the adsorption process. In this article, we studied the adsorption kinetics of AOT vesicles on silica at different pHs at ambient temperature. The AOT vesicles were formed in a brine solution. Quartz crystal microbalance with dissipation monitoring (QCM-D) was used to obtain information on the kinetics of surfactant adsorption and on the structure of the adsorbed layer at the equilibrium state. Additionally, neutron reflectivity experiments were performed to provide a detailed description of the mean surfactant concentration profile normal to the surface at equilibrium. Results suggest that vesicles in the bulk influence the adsorption mechanisms. In acidic conditions, after a time-dependent structural rearrangement step, followed by the rupture of initially adsorbed vesicles, the formation of a bilayer was observed. At an intermediate and basic pH, in spite of the electrostatic repulsion between the negatively charged surfactants and silica, results demonstrated the existence of an adsorbed layer composed of AOT vesicles. Vesicles are more or less closely packed depending on the pH of the solution. Results show a non-negligible influence of NaCl addition at pH values where adsorption is initially inhibited. Vesicle adsorption at the intermediate and basic pH is probably due to the combination of attractive van der Waals interactions promoted in high ionic strength systems and the formation of hydrogen bonds. Interpretation of adsorption kinetics gave insight into adsorption mechanisms in an electrostatic repulsion environment.
Published: 2020
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25. Location of Imbibed Solvent in Polymer-Grafted Nanoparticle Membranes

Author: Jacques Jestin, Eileen Buenning, Brian C. Benicewicz, Yucheng Huang, Sanat K. Kumar, and Christopher J. Durning
Subjects: chemistry.chemical_classification, Materials science, Nanocomposite, Polymers and Plastics, Organic Chemistry, Nanoparticle, 02 engineering and technology, Polymer, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, Solvent, Membrane, chemistry, Chemical engineering, Permeability (electromagnetism), Materials Chemistry, Thin film, Small-angle scattering, 0210 nano-technology
Abstract: Membranes made purely from nanoparticles (NPs) grafted with polymer chains show increased gas permeability relative to the analogous neat polymer films, with this effect apparently being tunable with systematic variations in polymer graft density and molecular weight. To explore the structural origins of these unusual transport results, we use small angle scattering (neutron, X-ray) on the dry nanocomposite film and to critically examine in situ the structural effects of absorbed solvent. The relatively low diffusion coefficients of typical solvents (∼10–12 m2/s) restricts us to thin films (≈1 μm in thickness) if solute concentration profiles are to equilibrate on the 1 s time scale. The use of such thin films, however, renders them as weak scatterers. Inspired by our nearly two decades old previous work, we address these conflicting requirements through the use of a custom designed flow cell, where stacks of 10 individual ≈1 μm thick supported films are used, while ensuring that each film is individually...
Published: 2018
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26. Melt Chain Conformation in Nanoparticles/Polymer Nanocomposites Elucidated by the SANS Extrapolation Method: Evidence of the Filler Contribution

Author: Fabrice Cousin, Florian Meneau, Anne-Sophie Robbes, and Jacques Jestin
Subjects: chemistry.chemical_classification, Nanocomposite, Materials science, Polymers and Plastics, Polymer nanocomposite, Organic Chemistry, Nanoparticle, Maghemite, 02 engineering and technology, Polymer, engineering.material, 021001 nanoscience & nanotechnology, 01 natural sciences, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Chemical engineering, 0103 physical sciences, Materials Chemistry, engineering, Magnetic nanoparticles, Polystyrene, 010306 general physics, 0210 nano-technology, Dispersion (chemistry)
Abstract: We probe by SANS the conformation of polymer chains of the matrix in various nanocomposites based on the same building blocks, namely spherical magnetic nanoparticles of maghemite (γ-Fe2O3) as fillers and polystyrene (PS) for the matrix. Given that the nanoparticles can be arranged in oriented chains during the processing by an external magnetic field and/or grafted by tethered PS chains with a grafting density of ∼0.15 chains/nm2, very different organizations of the nanofillers were tested according to different particle–polymer interactions: (i) homogeneous isotropic dispersion of aggregates of bare nanoparticles; (ii) chains of bare nanoparticles oriented along one direction over the whole sample; (iii) perfect dispersion of grafted nanoparticles; (iv) homogeneous isotropic dispersion of large aggregates of grafted nanoparticles; and (v) chains of large aggregates of grafted nanoparticles objects oriented along one direction over the whole sample. Measurements were performed by the extrapolation to the...
Published: 2018
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27. Preparation of water-soluble graphene nanoplatelets and highly conductive films

Author: Xuezhu Xu, Jacques Jestin, Veronica Colombo, Jian Zhou, and Gilles Lubineau
Subjects: Aqueous solution, Fullerene, Materials science, Graphene, Nanotechnology, 02 engineering and technology, General Chemistry, Carbon nanotube, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, law.invention, symbols.namesake, X-ray photoelectron spectroscopy, law, symbols, General Materials Science, 0210 nano-technology, Dispersion (chemistry), Raman spectroscopy, Graphene nanoribbons
Abstract: This paper tackles the challenge of preparation stable, highly concentrated aqueous graphene dispersions. Despite tremendous recent interest, there has been limited success in developing a method that ensures the total dispersion of non-oxidized, defect-free graphene nanosheets in water. This study successfully demonstrates that few-layer graphene nanoplatelets (GNPs) can form highly concentrated aqueous colloidal solutions after they have been pretreated in a low-concentration inorganic sodium-hypochlorite and sodium-bromide salted aqueous solvent. This method retains the graphitic structure as evidenced by nuclear magnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. Vacuum-filtrated freestanding films demonstrate an electrical conductivity as high as 3000 S m −1 . This dispersion technique is believed to be applicable not only for GNPs, but also for dispersing other types of graphitic materials, including fullerenes, single/double/multi-walled carbon nanotubes, graphene nanoribbons and etc.
Published: 2017
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28. Crucial Role of the Spacer in Tuning the Length of Self-Assembled Nanorods

Author: François Stoffelbach, Jacques Jestin, Laurent Bouteiller, Gaëlle Mellot, Shuaiyuan Han, Jutta Rieger, Olivier Colombani, Sandrine Pensec, Erwan Nicol, Institut Parisien de Chimie Moléculaire (IPCM), Chimie Moléculaire de Paris Centre (FR 2769), Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), 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)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Sorbonne Université (SU)-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), LLB - Matière molle et biophysique (MMB), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Université Pierre et Marie Curie - Paris 6 (UPMC)-ESPCI ParisTech-Ecole Nationale Supérieure de Chimie de Paris- Chimie ParisTech-PSL (ENSCP)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-ESPCI ParisTech-Ecole Nationale Supérieure de Chimie de Paris- Chimie ParisTech-PSL (ENSCP)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: Tris, inorganic chemicals, Aromatic compounds, Materials science, Polymers and Plastics, Polymers, Supramolecular chemistry, 02 engineering and technology, macromolecular substances, 010402 general chemistry, 01 natural sciences, Self assembled, Inorganic Chemistry, chemistry.chemical_compound, Polymer chemistry, Materials Chemistry, [CHIM]Chemical Sciences, Self organization, Alkyl, chemistry.chemical_classification, Organic Chemistry, technology, industry, and agriculture, 021001 nanoscience & nanotechnology, Toluene, Hydrocarbons, 0104 chemical sciences, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Urea, Nanorods, lipids (amino acids, peptides, and proteins), Nanorod, Polystyrene, 0210 nano-technology
Abstract: International audience; Polymeric supramolecular nanorods were prepared in toluene by self-assembly of tris(urea) stickers connected on both sides through alkyl spacers of different lengths to short polystyrene (PS) arms. Several tris(urea) initiators or chain transfer agents were synthesized straightforwardly and used to grow well-defined PS arms via atom transfer radical polymerization (ATRP) or reversible addition fragmentation chain transfer (RAFT) polymerization. Self-assembly was investigated by means of Fourier-transform infrared (FTIR) spectroscopy and light/neutron scattering. A dramatic impact of the spacer separating the tris(urea) sticker from the PS arms on the extent of self-assembly was observed in toluene as long as the degree of polymerization of the PS arms (x) was kept short (x ∼ 10). Indeed, supramolecular nanorods several hundreds of nanometers in length for a few nanometers in radius were obtained with a spacer consisting of nine atoms, whereas five times shorter nanorods were obtained for a spacer of only five atoms, and spherical particles were found in the absence of any spacer, all other parameters remaining unchanged. These results reveal the possibility to tune the length of polymer-decorated supramolecular nanorods with minimal modification of the assembling sticker and without affecting the functionality of the rods.
Published: 2020
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29. Tuning Selectivities in Gas Separation Membranes Based on Polymer-Grafted Nanoparticles

Author: Daniele Parisi, Christopher J. Durning, Michael Rubinstein, Yucheng Huang, Marcel Dickmann, Ferruccio Doghieri, Brian C. Benicewicz, Zaid M. Abbas, Arash Nikoubashman, Dimitris Vlassopoulos, Matteo Minelli, Connor Bilchak, Jacques Jestin, Sanat K. Kumar, Francesco M. Benedetti, Jiarul Midya, Zachary P. Smith, Ludwik Leibler, Mayank Jhalaria, Werner Egger, Bilchak C.R., Jhalaria M., Huang Y., Abbas Z., Midya J., Benedetti F.M., Parisi D., Egger W., Dickmann M., Minelli M., Doghieri F., Nikoubashman A., Durning C.J., Vlassopoulos D., Jestin J., Smith Z.P., Benicewicz B.C., Rubinstein M., Leibler L., and Kumar S.K.
Subjects: Materials science, heterogeneous transport media, improved selective transport, Synthetic membrane, General Physics and Astronomy, Nanoparticle, gas separation membrane, Context (language use), 02 engineering and technology, 010402 general chemistry, 01 natural sciences, General Materials Science, Gas separation, free volume distribution, chemistry.chemical_classification, polymer-grafted nanoparticles, General Engineering, Polymer, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Membrane, chemistry, Chemical engineering, Volume (thermodynamics), mixed matrix membrane, 0210 nano-technology, Selectivity
Abstract: Polymer membranes are critical to many sustainability applications that require the size-based separation of gas mixtures. Despite their ubiquity, there is a continuing need to selectively affect the transport of different mixture components while enhancing mechanical strength and hindering aging. Polymer-grafted nanoparticles (GNPs) have recently been explored in the context of gas separations. Membranes made from pure GNPs have higher gas permeability and lower selectivity relative to the neat polymer because they have increased mean free volume. Going beyond this ability to manipulate the mean free volume by grafting chains to a nanoparticle, the conceptual advance of the present work is our finding that GNPs are spatially heterogeneous transport media, with this free volume distribution being easily manipulated by the addition of free polymer. In particular, adding a small amount of appropriately chosen free polymer can increase the membrane gas selectivity by up to two orders of magnitude while only moderately reducing small gas permeability. Added short free chains, which are homogeneously distributed in the polymer layer of the GNP, reduce the permeability of all gases but yield no dramatic increases in selectivity. In contrast, free chains with length comparable to the grafts, which populate the interstitial pockets between GNPs, preferentially hinder the transport of the larger gas and thus result in large selectivity increases. This work thus establishes that we can favorably manipulate the selective gas transport properties of GNP membranes through the entropic effects associated with the addition of free chains.
Published: 2020

30. Effects of Hairy Nanoparticles on Polymer Crystallization Kinetics

Author: Dan Zhao, Jacques Jestin, Sanat K. Kumar, Ricardo A. Pérez-Camargo, Brian C. Benicewicz, Alejandro J. Müller, Alejandro A. Krauskopf, Julia Pribyl, Andrew Jimenez, Department of Chemical Engineering, Columbia University, Columbia University [New York], Departamento de Ciencia y Tecnologıa de Polımeros e Instituto de Materiales Polimericos (POLYMAT), Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), Department of Chemistry and Biochemistry [Columbia, South Carolina], University of South Carolina [Columbia], LLB - Matière molle et biophysique (MMB), Laboratoire Léon Brillouin (LLB - UMR 12), 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), Department of Chemistry and Biochemistry [South Carolina Columbia], and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay
Subjects: Materials science, Polymers and Plastics, Crystallization of polymers, Crystal growth, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Article, law.invention, Inorganic Chemistry, Crystal, Crystallinity, law, Materials Chemistry, Lamellar structure, Crystallization, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], [PHYS]Physics [physics], Organic Chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Amorphous solid, Chemical engineering, Melting point, 0210 nano-technology, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
Abstract: International audience; We previously showed that nanoparticles (NPs) could be ordered into structures by using the growth rate of polymer crystals as the control variable. In particular, for slow enough spherulitic growth fronts, the NPs grafted with amorphous polymer chains are selectively moved into the interlamellar, interfibrillar, and interspherulitic zones of a lamellar morphology, specifically going from interlamellar to interspherulitic with progressively decreasing crystal growth rates. Here, we examine the effect of NP polymer grafting density on crystallization kinetics. We find that while crystal nucleation is practically unaffected by the presence of the NPs, spherulitic growth, final crystallinity, and melting point values decrease uniformly as the volume fraction of the crystallizable polymer, poly(ethylene oxide) or PEO, ϕPEO, decreases. A surprising aspect here is that these results are apparently unaffected by variations in the relative amounts of the amorphous polymer graft and silica NPs at constant ϕ, implying that chemical details of the amorphous defect apparently only play a secondary role. We therefore propose that the grafted NPs in this size range only provide geometrical confinement effects which serve to set the crystal growth rates and melting point depressions without causing any changes to crystallization mechanisms.
Published: 2019
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31. Morphologies of Polyisoprene-Grafted Silica Nanoparticles in Model Elastomers

Author: Didier Gigmes, Deboleena Dhara, Jacques Jestin, Sanat K. Kumar, Brian C. Benicewicz, Marc Couty, Zaid M. Abbas, Marine Bonnevide, Nicolas Malicki, Trang N. T. Phan, Andrew Jimenez, Institut de Chimie Radicalaire (ICR), Aix Marseille Université (AMU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), LLB - Matière molle et biophysique (MMB), Laboratoire Léon Brillouin (LLB - UMR 12), 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), Department of Chemical Engineering [Columbia], University of Missouri [Columbia] (Mizzou), University of Missouri System-University of Missouri System, Centre de Technologie de Ladoux, Société Michelin, Department of Chemistry and Biochemistry [Columbia, South Carolina], University of South Carolina [Columbia], Department of Chemical Engineering, Columbia University, Columbia University [New York], Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, and Department of Chemistry and Biochemistry [South Carolina Columbia]
Subjects: [PHYS]Physics [physics], Work (thermodynamics), Materials science, Polymers and Plastics, Pi system, Organic Chemistry, Nanoparticle, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Microstructure, Elastomer, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, Matrix (mathematics), Chemical physics, Materials Chemistry, Copolymer, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Dispersion (chemistry), [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
Abstract: International audience; We control nanoparticle (NP) dispersion by leveraging the entropic and enthalpic effects associated with mixing silica NPs grafted with polyisoprene (PI) chains into matrices of varying degrees of chemical dissimilarity. Previous work in this area has primarily focused on entropic factors alone, and hence, this work represents a significant advance over the current state-of-the-art. We show using a combination of transmission electron microscopy/small-angle X-ray scattering that mixing grafted particles with PI matrices of identical microstructure yields dispersion states as found in the literature for such entropic systems. However, replacing the PI matrix chains with dissimilar matrices leads to an introduction of enthalpic interactions that, in some cases, can drastically change the resulting morphology. In particular, while slightly different PI microstructures for the grafted and free chains only yield moderated differences, using styrene–butadiene copolymers as a matrix leads to a completely different behavior. In the last case, phase separation becomes more likely with the increasing graft length, while the PI system (whose behavior is dominated by entropic factors) shows the opposite behavior. Tuning the relative importance of enthalpic versus entropic factors is thus another tool in controlling the self-assembled structure of NPs, which gives rise to enhanced macroscopic properties in the composite.
Published: 2019
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32. Accelerated Local Dynamics in Matrix-Free Polymer Grafted Nanoparticles

Author: Mayank Jhalaria, Yucheng Huang, Victoria Garcia-Sakai, Eileen Buenning, Jacques Jestin, Sanat K. Kumar, Michaela Zamponi, Madhusudan Tyagi, Reiner Zorn, Brian C. Benicewicz, Department of Chemical Engineering, Columbia University, Columbia University [New York], Department of Chemistry and Biochemistry [Columbia, South Carolina], University of South Carolina [Columbia], NIST Center for Neutron Research, National Institute of Standards and Technology [Gaithersburg] (NIST), Forschungszentrum Jülich, JCNS-1/ICS-1, 52428 Jülich, Germany, Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association, ISIS Neutron and Muon Source (ISIS), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC)-Science and Technology Facilities Council (STFC), LLB - Matière molle et biophysique (MMB), Laboratoire Léon Brillouin (LLB - UMR 12), 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), Department of Chemistry and Biochemistry [South Carolina Columbia], and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay
Subjects: chemistry.chemical_classification, [PHYS]Physics [physics], Quantitative Biology::Biomolecules, Materials science, Jump diffusion, General Physics and Astronomy, Nanoparticle, Polymer, Polymer brush, 01 natural sciences, Solvent, Condensed Matter::Soft Condensed Matter, Chain length, Membrane, chemistry, Chemical physics, 0103 physical sciences, Quasielastic neutron scattering, ddc:530, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
Abstract: International audience; The tracer diffusion coefficient of six different permanent gases in polymer-grafted nanoparticle (GNP) membranes, i.e., neat GNP constructs with no solvent, show a maximum as a function of the grafted chain length at fixed grafting density. This trend is reproduced for two different NP sizes and three different polymer chemistries. We postulate that nonmonotonic changes in local, segmental friction as a function of graft chain length (at fixed grafting density) must underpin these effects, and use quasielastic neutron scattering to probe the self-motions of polymer chains at the relevant segmental scale (i.e., sampling local friction or viscosity). These data, when interpreted with a jump diffusion model, show that, in addition to the speeding-up in local chain dynamics, the elementary distance over which segments hop is strongly dependent on graft chain length. We therefore conclude that transport modifications in these GNP layers, which are underpinned by a structural transition from a concentrated brush to semidilute polymer brush, are a consequence of both spatial and temporal changes, both of which are likely driven by the lower polymer densities of the GNPs relative to the neat polymer.
Published: 2019
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33. A Competing Hydrogen Bonding Pattern to Yield Thermo-Thickening Supramolecular Polymer

Author: Benjamin Isare, Matthieu Raynal, Virgile Ayzac, Laurent Bouteiller, Jacques Jestin, Quentin Sallembien, Chimie des polymères (LCP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Parisien de Chimie Moléculaire (IPCM), Chimie Moléculaire de Paris Centre (FR 2769), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), 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)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Chimie Moléculaire de Paris Centre (FR 2769), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Léon Brillouin (LLB - UMR 12), 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)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Chimie Moléculaire de Paris Centre (FR 2769), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay
Subjects: Materials science, urea, 010402 general chemistry, pathway complexity, 01 natural sciences, Catalysis, Rod, Viscosity, [CHIM]Chemical Sciences, Fourier transform infrared spectroscopy, supramolecular polymers, chemistry.chemical_classification, 010405 organic chemistry, Scattering, Hydrogen bond, General Chemistry, General Medicine, self-assembly, 0104 chemical sciences, Supramolecular polymers, Crystallography, chemistry, Chemical engineering, Yield (chemistry), hydrogen bonds, Self-assembly, Thickening
Abstract: International audience; Introduction of competing interactions in the design of a supramolecular polymer (SP) creates pathway complexity. Ester–bis‐ureas contain both a strong bis‐urea sticker that is responsible for the build‐up of long rod‐like objects by hydrogen bonding and ester groups that can interfere with this main pattern in a subtle way. Spectroscopic (FTIR and CD), calorimetric (DSC), and scattering (SANS) techniques show that such ester–bis‐ureas self‐assemble into three competing rod‐like SPs. The previously unreported low‐temperature SP is stabilized by hydrogen bonds between the interfering ester groups and the urea moieties. It also features a weak macroscopic alignment of the rods. The other structures form isotropic dispersions of rods stabilized by the more classical urea‐urea hydrogen bonding pattern. The transition from the low‐temperature structure to the next occurs reversibly by heating and is accompanied by an increase in viscosity, a rare feature for solutions in hydrocarbons.
Published: 2019
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34. Robust supramolecular nanocylinders of naphthalene diimide in water

Author: Marc Sallé, Jacques Jestin, Olivier Colombani, Frédérick Niepceron, David Canevet, Thomas Choisnet, Erwan Nicol, 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), MOLTECH-Anjou, Université d'Angers (UA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Léon Brillouin (LLB - UMR 12), 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)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS), MOLTECH-ANJOU (MOLTECH-ANJOU), and Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA)
Subjects: Materials science, Aspect ratio, Ethylene oxide, 010405 organic chemistry, Hydrogen bond, Metals and Alloys, Supramolecular chemistry, General Chemistry, 010402 general chemistry, 01 natural sciences, Catalysis, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry.chemical_compound, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Chemical engineering, Materials Chemistry, Ceramics and Composites, Urea, Naphthalene diimide, Solubility, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; Naphthalene-diimide (NDI)-containing nanocylinders were formed by supramolecular self-assembly in water through cooperative hydrogen bonds between bis(urea) units, reinforced by hydrophobic and aromatic-stacking interactions. The nanocylinders, decorated with poly(ethylene oxide) arms ensuring their solubility in water, exhibit a huge aspect ratio (diameter 13 nm, length 300 nm) and are extremely stable.
Published: 2019
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35. Structure of alumina-silica nanoparticles grafted with alkylphosphonic acids in poly(ethylacrylate) nanocomposites

Author: Céline Schmitt Pauly, Michael Sztucki, Johan G. Alauzun, P. Hubert Mutin, Jacques Jestin, Julian Oberdisse, Anne-Caroline Genix, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Physique des Verres, Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), and Matière Molle
Subjects: Materials science, Polymers and Plastics, Polymer nanocomposite, education, Nanoparticle, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, Colloid, Polymer chemistry, Materials Chemistry, Alkyl, chemistry.chemical_classification, Aqueous solution, Nanocomposite, Organic Chemistry, technology, industry, and agriculture, Diethylene glycol, Polymer, 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, Chemical engineering, 0210 nano-technology, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
Abstract: Alumina-coated silica nanoparticles (NPs) grafted with phosphonic acids of different hydrophobicity were used as filler in poly(ethylacrylate) nanocomposites. Phosphonic acids bearing short alkyl chains or a diethylene glycol group have been grafted at densities up to 3.2 P/nm 2 on NPs (20 nm) dispersed in water. Nanocomposites at particle fractions up to 10 vol% have been formulated by casting from the colloidal mixtures of modified NPs and nanolatex in water. The dispersion of the NPs in the polymer matrix has been studied by TEM combined with small-angle scattering, evidencing aggregation of NPs. TEM shows micrometer-scale inhomogeneities depending on the surface/polymer matrix compatibility. For the local interparticle correlations, a quantitative analysis of the intensity based on the mapping onto the effective structure factor of polydisperse hard spheres is developed. This mapping allows the model-free determination of the internal volume fraction of aggregates, termed compacity κ, to between 10% and 30%, compatible with the TEM analysis. κ is found to increase for the higher particle volume fractions, to decrease with grafting density, and to be mostly independent of the nature and mass of the graft. Preliminary evidence for an improved compatibility of grafted with respect to bare NPs is found, as opposed to their aqueous precursor suspensions where some pre-aggregation is induced by grafting.
Published: 2016
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36. Polymer Chain Behavior in Polymer Nanocomposites with Attractive Interactions

Author: Changzai Chi, Michael Crawford, Jacques Jestin, Sanat K. Kumar, William Guise, Yuri B. Melnichenko, Robert J. Smalley, Nicolas Jouault, Lilin He, and Barbara A. Wood
Subjects: chemistry.chemical_classification, Materials science, Polymers and Plastics, Polymer nanocomposite, Organic Chemistry, 02 engineering and technology, Polymer, Neutron scattering, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Spectral line, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Chain (algebraic topology), Chemical engineering, Materials Chemistry, Radius of gyration, Methyl methacrylate, Composite material, 0210 nano-technology, Layer (electronics)
Abstract: Chain behavior has been determined in polymer nanocomposites (PNCs) comprised of well-dispersed 12 nm diameter silica nanoparticles (NPs) in poly(methyl methacrylate) (PMMA) matrices by Small-Angle Neutron Scattering (SANS) measurements under the Zero Average Contrast (ZAC) condition. In particular, we directly characterize the bound polymer layer surrounding the NPs, revealing the bound layer profile. The SANS spectra in the high-q region also show no significant change in the bulk polymer radius of gyration on the addition of the NPs. We thus suggest that the bulk polymer conformation in PNCs should generally be determined using the high q region of SANS data.
Published: 2016
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37. Author Correction: Straightforward preparation of supramolecular Janus nanorods by hydrogen bonding of end-functionalized polymers

Author: Erwan Nicol, Laurent Bouteiller, Jacques Jestin, Dijwar Yilmaz, Sandrine Pensec, Cédric Lorthioir, François Stoffelbach, Olivier Colombani, Shuaiyuan Han, Jutta Rieger, Jean-Michel Guigner, and Frédérick Niepceron
Subjects: chemistry.chemical_classification, Multidisciplinary, Materials science, Hydrogen bond, Science, Supramolecular chemistry, General Physics and Astronomy, Nanotechnology, General Chemistry, Polymer, General Biochemistry, Genetics and Molecular Biology, chemistry, Nanorod, lcsh:Q, Janus, lcsh:Science
Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Published: 2020

38. Iron speciation in iron–organic matter nanoaggregates: a kinetic approach coupling Quick-EXAFS and MCR-ALS chemometrics

Author: Mélanie Davranche, Jacques Jestin, Anthony Beauvois, Hélène Guénet, Valérie Briois, Camille La Fontaine, Rémi Marsac, Grace Campaore, Delphine Vantelon, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), LLB - Matière molle et biophysique (MMB), Laboratoire Léon Brillouin (LLB - UMR 12), 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), ANR-10-EQPX-45, Agence Nationale de la Recherche, ANR-10-EQPX-0045,ROCK,Spectromètre EXAFS Rapide pour Cinétiques Chimiques(2010), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)
Subjects: chemistry.chemical_classification, Materials Science (miscellaneous), Inorganic chemistry, 02 engineering and technology, 010501 environmental sciences, 021001 nanoscience & nanotechnology, 01 natural sciences, Oligomer, Metal, chemistry.chemical_compound, Hydrolysis, Ferrihydrite, chemistry, Polymerization, 13. Climate action, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, visual_art, visual_art.visual_art_medium, Humic acid, Organic matter, Metalloid, 0210 nano-technology, 0105 earth and related environmental sciences, General Environmental Science
Abstract: International audience; Iron–organic matter (Fe–OM) nanoaggregates are highly abundant in wetlands. Iron oxyhydroxides and natural OM are strong sorbents for metals and metalloids due to their high density of binding sites. They are thus considered as a major vector for the transport of metallic pollutants in this type of aquatic system. However, their structural organization is complex and varies under physico-chemical environmental conditions. The goal of this present study is to characterize these various iron phases and their growth processes. The formation of Fe-species was followed by Quick-EXAFS during oxidation/hydrolysis kinetics of pre-formed Fe(II)–humic acid complexes. Data were then processed using the MCR-ALS chemometric method. It demonstrated that, in the presence of OM, Fe(II) oxidation/hydrolysis leads to the synthesis of Fe-oligomers and ferrihydrite-like nanoparticles, both being bound to OM. The formation of the oligomers is the result of the inhibition of ferrihydrite polymerization by OM. Ferrihydrite and oligomers grow concomitantly during Fe(II) oxidation. When Fe(II) is completely oxidized, ferrihydrite forms at the expense of oligomers. For a given Fe/OM ratio, the ferrihydrite/oligomer ratio depends on the oxidation/hydrolysis kinetics which is strongly influenced by O2 and OH− availability. The organization of these structures constrains their binding site density and availability, which induces dramatic environmental implications regarding their capacity to trap metallic pollutants.
Published: 2019
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39. Synthesis of polyisoprene, polybutadiene and Styrene Butadiene Rubber grafted silica nanoparticles by nitroxide-mediated polymerization

Author: Marine Bonnevide, Sanat K. Kumar, Didier Gigmes, Nicolas Malicki, Jacques Jestin, Marc Couty, and Trang N. T. Phan
Subjects: chemistry.chemical_classification, Nitroxide mediated radical polymerization, Styrene-butadiene, Materials science, Polymers and Plastics, Organic Chemistry, 02 engineering and technology, Polymer, 010402 general chemistry, 021001 nanoscience & nanotechnology, Elastomer, 01 natural sciences, 0104 chemical sciences, Styrene, chemistry.chemical_compound, Monomer, Polybutadiene, chemistry, Chemical engineering, Polymerization, Materials Chemistry, 0210 nano-technology
Abstract: We present a new application of nitroxide mediated polymerization (NMP) for grafting of various elastomers onto the surfaces of silica nanoparticles (NPs) while ensuring colloidal stability and thus avoiding particle aggregation. While NMP has been used to graft chains from NP surfaces, our novel contributions are thus two-fold. We show for the first time that this methodology, initially demonstrated for styrene polymerization, can be extended to a variety of other relevant polymer chemistries, i.e., to isoprene, butadiene and styrene-butadiene rubber. We optimize the synthesis conditions for the different monomers under critical pressure conditions and characterize the grafted chains in solution by a combination of small angle x-ray and neutron scattering (with deuterated solvent labelling) to quantitatively describe the grafted chain composition. Second, crucially, we characterized the colloidal stability of the particles during the different steps of the grafting process. We have found that particle aggregation can (and does) occur at a variety of points during synthesis, and hence we have performed a detailed refined characterization of NP agglomeration and then found methods to mitigate it at each stage. These steps ensure that we can begin the preparation of composite materials from a well-defined starting point.
Published: 2020
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40. Bisurea-Functionalized RAFT Agent: A Straightforward and Versatile Tool toward the Preparation of Supramolecular Cylindrical Nanostructures in Water

Author: Laurent Bouteiller, Jacques Jestin, Jean-Michel Guigner, Gaëlle Mellot, Jutta Rieger, François Stoffelbach, Chimie des polymères (LCP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Parisien de Chimie Moléculaire (IPCM), Chimie Moléculaire de Paris Centre (FR 2769), Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), 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)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Chimie Moléculaire de Paris Centre (FR 2769), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-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 Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, LLB - Matière molle et biophysique (MMB), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Chimie Moléculaire de Paris Centre (FR 2769), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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), 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), ANR-17-CE09-0031,PISAForFilms,Revêtements acryliques aqueux aux propriétés renforcées(2017), Institut Parisien de Chimie Moléculaire (IPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-ESPCI ParisTech-Ecole Nationale Supérieure de Chimie de Paris- Chimie ParisTech-PSL (ENSCP)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-ESPCI ParisTech-Ecole Nationale Supérieure de Chimie de Paris- Chimie ParisTech-PSL (ENSCP)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), LLB - Nouvelles frontières dans les matériaux quantiques (NFMQ), and École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Nationale Supérieure de Chimie de Paris- Chimie ParisTech-PSL (ENSCP)-ESPCI ParisTech-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Nationale Supérieure de Chimie de Paris- Chimie ParisTech-PSL (ENSCP)-ESPCI ParisTech-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: chemistry.chemical_classification, Materials science, Polymers and Plastics, Organic Chemistry, Polyacrylamide, Supramolecular chemistry, 02 engineering and technology, Polymer, Raft, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Micelle, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Polymerization, Chemical engineering, Materials Chemistry, Ethyl acrylate, [CHIM]Chemical Sciences, 0210 nano-technology, Acrylic acid
Abstract: International audience; We report a versatile and simple approach to produce cylindrical micelles by the direct dissolution of polymers in water. The developed strategy relies on a RAFT agent functionalized by a bisurea sticker that allowed to synthesize a series of α-bisurea-functionalized poly(N,N-dimethylacrylamide) (PDMAc), poly(acrylic acid) (PAA), polyacrylamide (PAM), and poly(2-(N,N-dimethylamino)ethyl acrylate) (PDMAEA) with number-average degrees of polymerization (DPn) varying from about 10 to 50. Their spontaneous self-assembly in water was studied by electron microscopy (cryo-TEM), neutron scattering (SANS), and calorimetry (ITC) analyses which showed that long cylindrical micelles are spontaneously formed in water. The crucial role of the bisurea sticker end-groups was established by comparison with the corresponding bisurea-free model polymers that only formed spherical micelles. Finally, we have shown that it is possible to trigger reversibly the assembly/disassembly of the nanofibers by pH changes.
Published: 2018
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41. Ionic PMMA/nanosilica interfaces from grafting ionic liquids under supercritical CO2 conditions

Author: Sébastien Livi, Jean-François Gérard, Jannick Duchet, Clarice Fedosse Zornio, Jacques Jestin, Ingénierie des Matériaux Polymères (IMP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet [Saint-Étienne] (UJM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: chemistry.chemical_classification, Thermogravimetric analysis, Supercritical carbon dioxide, Nanocomposite, Materials science, Polymers and Plastics, Organic Chemistry, General Physics and Astronomy, Nanoparticle, 02 engineering and technology, Polymer, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Supercritical fluid, 0104 chemical sciences, chemistry.chemical_compound, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Chemical engineering, Ionic liquid, Materials Chemistry, 0210 nano-technology, Alkyl
Abstract: International audience; Supercritical carbon dioxide (scCO2) was considered as an environmental friendly medium for grafting the surface of silica nanoparticles with a series of reactive imidazolium-based ionic liquids (IL), denoted as IL-silanes. The effects of the reaction conditions on the resulting IL-grafted layers on the silica surface were characterized from thermogravimetric (TGA) and transmission electronic microscopy (TEM) analyses. The IL-grafted nanoparticles were introduced into poly(methyl methacrylate) (PMMA) via melt mixing in order to design nanocomposites and to demonstrate the ability of IL-grafted nanoparticles to be dispersed into a polymer medium. The role of the IL-grafted surfaces on the morphology of PMMA-based nanocomposites was evidenced by TEM and small angle neutron scattering (SANS). It was demonstrated that longer the alkyl chain length of the IL-silane, better the state of dispersion of nanoparticles within PMMA. In addition, better thermal stabilities and mechanical performances, as well as new surface properties were observed for the designed PMMA-based nanocomposites.
Published: 2018
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42. Experimental evidence of REE size fraction redistribution during redox variation in wetland soil

Author: Delphine Vantelon, Martine Bouhnik-Le Coz, Emilie Jardé, Anne-Catherine Pierson-Wickmann, Aline Dia, Mélanie Davranche, Hélène Guénet, Edwige Demangeat, Elaheh Lotfi, Jacques Jestin, Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ANR-JC-11-JS56-0010, ANR, IUFIUF, ANR-11-JS56-0010,ARSENORG,Interactions entre arsenic, matière organique et oxydes de fer. Les zones humides sont-elles des sources d'arsenic pour les aquifères ?(2011), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), ANR-JC-11-JS56-0010, ANRANR, Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)
Subjects: Environmental Engineering, Iron, Redox alternation, Fractionation, 010501 environmental sciences, 010502 geochemistry & geophysics, 01 natural sciences, Redox, GEOF, Colloid, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Environmental Chemistry, Organic matter, Waste Management and Disposal, Dissolution, Rare earth elements, 0105 earth and related environmental sciences, chemistry.chemical_classification, Chemistry, Rare-earth element, Trace element, 15. Life on land, Particulates, Pollution, Environmental chemistry, Wetland, Nanoparticles
Abstract: International audience; The evolution of rare earth element (REE) speciation between reducing and oxidizing conditions in a riparian wetland soil was studied relative to the size fractionation of the solution. In all size fractions obtained from the reduced and oxidized soil solutions, the following analyses were carried out: organic matter (OM) characterization, transmission electron microscopy (TEM) observations as well as major and trace element analyses. Significant REE redistribution and speciation evolution between the various size fractions were observed. Under reducing conditions, the REEs were bound to colloidal and dissolved OM (2 μm size fraction), colloidal (
Published: 2018
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43. Aromatic Copolymer/Nafion Blends Outperforming the Corresponding Pristine Ionomers

Author: Jacques Jestin, Sandrine Lyonnard, Cristina Iojoiu, Huu-Dat Nguyen, Lionel Porcar, Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces (LEPMI ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), LLB - Matière molle et biophysique (MMB), Laboratoire Léon Brillouin (LLB - UMR 12), 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 Laue-Langevin (ILL), Synthèse, Structure et Propriétés de Matériaux Fonctionnels (STEP), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, ILL, Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: Materials science, Arylene, Energy Engineering and Power Technology, 02 engineering and technology, Conductivity, 010402 general chemistry, 021001 nanoscience & nanotechnology, Microstructure, 01 natural sciences, Casting, 0104 chemical sciences, chemistry.chemical_compound, Membrane, chemistry, Chemical engineering, Nafion, Materials Chemistry, Electrochemistry, Copolymer, Chemical Engineering (miscellaneous), Polymer blend, Electrical and Electronic Engineering, 0210 nano-technology, polymer blend aromatic ionomers block copolymers Nafion blend poly(arylene ether sulfone) PEMFCs proton-exchange membranes SANS, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
Abstract: International audience; In this work we investigated the impact of Nafion as a percolating agent of aromatic copolymer ionic channels. Membranes based on a blend of Nafion and copoly(arylene ether sulfone)s bearing perfluorosulfonic acid pendant chains (InX/Y) were prepared by casting. We demonstrated that, despite the partial immiscibility of flexible random Nafion and rigid aromatic ionomers, high-performance mechanically robust blend membranes could be obtained, exhibiting higher proton conductivities than those of the corresponding pristine ionomers. Thermal annealing reduced the water uptake while the proton conductivity was further enhanced, especially at low relative humidity. The best-performing blends were obtained with the annealed membranes containing 20 wt % Nafion; e.g., the proton conductivity reaches 3 times that of pristine Nafion cast in the same condition. These properties were correlated to the microstructure of the blend membranes, which was investigated by small-angle neutron scattering as a function of the blending ratio and the block lengths. The two ionomers were found to form phase-separated nanodomains, a morphology that is homogenized via applying thermal annealing. Nafion molecules are incorporated into the ion conducting phase of the aromatic ionomer, where they serve to better connect ionic channels, therefore providing facilitated pathways for a much more efficient long-range charge transfer.
Published: 2018
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44. Nanocomposites: general discussion

Author: Ramanan Krishnamoorti, Ajeet K. Srivastav, G. V. Pavan Kumar, Guruswamy Kumaraswamy, Jacques Jestin, Marc Couty, Madivala G. Basavaraj, Sanat K. Kumar, Himani Medhi, Bijai Prasad, Siddharth Kulkarni, Daan Frenkel, Vandana Shinde, Rajdip Bandyopadhyaya, Yogesh M. Joshi, Nicholas A. Kotov, Michael R. Bockstaller, Nagaraj P. Shetti, Erika Eiser, Neena S. John, Alison J. Edwards, Priyadarshi Roy Chowdhury, and Charusita Chakravarty
Subjects: Nanocomposite, Materials science, 0205 materials engineering, 020502 materials, Nanotechnology, 02 engineering and technology, Physical and Theoretical Chemistry
Published: 2016
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45. Modeling and Theory: general discussion

Author: Hima Bindu Kolli, Madivala G. Basavaraj, Ajeet K. Srivastav, G. V. Pavan Kumar, Alison J. Edwards, Priyadarshi Roy Chowdhury, Guruswamy Kumaraswamy, Bijai Prasad, Nirmalya Bachhar, Debdas Dhabal, Mohamed Laradji, Rajdip Bandyopadhyaya, Ranjini Bandyopadhyay, Jacques Jestin, Charusita Chakravarty, Mukta Tripathy, Sanat K. Kumar, Yogesh M. Joshi, Sudeep N. Punnathanam, Vimala Sridurai, Sunil Kumar, Jayant K. Singh, Oleg Gang, Vinothan N. Manoharan, Robert Botet, Daan Frenkel, Lynn M. Walker, Pedro A. Sánchez, Siddharth Kulkarni, Hari O. S. Yadav, Sofia S. Kantorovich, Nicholas A. Kotov, Vandana Shinde, and Erika Eiser
Subjects: Text mining, 010304 chemical physics, Computer science, business.industry, 0103 physical sciences, Physical and Theoretical Chemistry, 010402 general chemistry, business, 01 natural sciences, Data science, 0104 chemical sciences
Published: 2016
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46. From nanopores to macropores: Fractal morphology of graphite

Author: Wim G. Bouwman, Zhou Zhou, Catherine Pappas, Jacques Jestin, Sylvain Desert, Stefan Hartmann, and H. Schut
Subjects: Condensed Matter - Materials Science, Materials science, Condensed matter physics, Orders of magnitude (temperature), Neutron imaging, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, Nanotechnology, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Small-angle neutron scattering, Fractal dimension, 0104 chemical sciences, Characterization (materials science), Fractal, Spin echo, General Materials Science, Neutron, 0210 nano-technology
Abstract: We present a comprehensive structural characterization of two different highly pure nuclear graphites that compasses all relevant length scales from nanometers to sub-mm. This has been achieved by combining several experiments and neutron techniques: Small Angle Neutron Scattering (SANS), high-resolution Spin Echo SANS (SESANS) and neutron imaging. In this way it is possible to probe an extraordinary broad range of 6 orders of magnitude in length from microscopic to macroscopic length scales. The results reveal a fractal structure that extends from ∼0.6 nm to 0.6 mm and has surface and mass fractal dimensions both very close to 2.5, a value found for percolating clusters and fractured ranked surfaces in 3D.
Published: 2016
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47. Role of Filler Shape and Connectivity on the Viscoelastic Behavior in Polymer Nanocomposites

Author: Erkan Senses, Dan Zhao, Pinar Akcora, Shufan Ge, Jacques Jestin, and Sanat K. Kumar
Subjects: chemistry.chemical_classification, Materials science, Polymers and Plastics, Polymer nanocomposite, Colloidal silica, Organic Chemistry, technology, industry, and agriculture, Nanoparticle, Percolation threshold, Polymer, respiratory system, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Chemical engineering, Polymer chemistry, Materials Chemistry, Particle, Polystyrene, Fumed silica
Abstract: We compare the rheological behavior of three classes of polymer nanocomposites (PNCs) to understand the role of particle shape and interactions on mechanical reinforcement. The first two correspond to favorably interacting composites formed by mixing poly(2-vinylpyridine) with either fumed silica nanoparticles (NPs) or colloidal spherical silica NPs. We show that fumed silica NPs readily form a percolated network at low NP volume fractions. We deduce that the NPs act as network junctions with the effectively irreversibly bound polymer chains serving as the connecting bridges. By comparing with colloidal spherical silica, which has a significantly higher percolation threshold, we conclude that the fractal shape of the fumed silica is responsible for its unusually low percolation threshold. The third system corresponds to polystyrene grafted colloidal silica nanoparticles (PGNPs) in a polystyrene matrix. These PNCs have an even lower percolation threshold probably because the grafted chains increase the eff...
Published: 2015
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48. On the design and experimental realization of a multislit-based very small angle neutron scattering instrument at the European Spallation Source

Author: Sylvain Desert, Pascal Lavie, Jacques Jestin, Patrice Permingeat, Vincent Thevenot, Sohrab Abbas, and Annie Brûlet
Subjects: Physics, Scattering, business.industry, Collimator, Neutron radiation, Neutron scattering, Small-angle neutron scattering, General Biochemistry, Genetics and Molecular Biology, Neutron time-of-flight scattering, law.invention, Optics, law, Spallation, business, Scaling
Abstract: This article reports the design of a versatile multislit-based very small angle neutron scattering (VSANS) instrument working either as a dedicated instrument or as an add-on for any small-angle neutron scattering machine like the proposed SANS instrument, SKADI, at the future European Spallation Source. The use of multiple slits as a VSANS collimator for the time-of-flight techniques has been validated using McStas simulations. Various instrument configurations to achieve different minimum wavevector transfers in scattering experiments are proposed. The flexibility of the multislit VSANS instrument concept is demonstrated by showing the possibility of instrument length scaling for the first time, allowing access to varying minimum wavevector transfers with the same multislit setup. These options can provide smooth access to minimum wavevector transfers lower than ∼4 × 10−5 Å−1 and an overlapping of wavevector coverage with normal SANS mode, e.g. with the SKADI wavevector range of 10−3–1.1 Å−1. Such an angularly well defined and intense neutron beam will allow faster SANS studies of objects larger than 1 µm. Calculations have also been carried out for a radial collimator as an alternative to the multislit collimator setup. This extends the SANS Q range by an order of magnitude to 1 × 10−4 Å−1 with much simpler alignment. The multislit idea has been realized experimentally by building a prototype at Laboratoire Leon Brillouin, Saclay, with cross-talk-free geometry. Feasibility studies were carried out by making VSANS measurements with single- and multislit collimators, and the results are compared with multiple-pinhole geometry using classical SANS analysis tools.
Published: 2015
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49. Characterization of iron–organic matter nano- aggregate networks through a combination of SAXS/SANS and XAS analyses: impact on As binding

Author: Sebastian Jaksch, Delphine Vantelon, Vincent Dorcet, Julien Gigault, Hélène Guénet, Mathieu Pédrot, Sylvain Prévost, Mélanie Davranche, Jacques Jestin, Olivier Taché, Antoine Boutier, Géosciences Rennes (GR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), 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), Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), 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), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: chemistry.chemical_classification, X-ray absorption spectroscopy, Chemistry, Small-angle X-ray scattering, Materials Science (miscellaneous), Nanoparticle, Mineralogy, Sorption, [CHIM.MATE]Chemical Sciences/Material chemistry, 010501 environmental sciences, 010502 geochemistry & geophysics, 01 natural sciences, Metal, Adsorption, Chemical engineering, Dynamic light scattering, 13. Climate action, visual_art, visual_art.visual_art_medium, Organic matter, 0105 earth and related environmental sciences, General Environmental Science
Abstract: International audience; Nanoparticles play an important role in controlling the mobility of pollutants such as arsenic (As) in the environment. In natural waters, aggregates of nanoparticles can be constituted of organic matter (OM) associated with iron (Fe). However, little is known about their network structure, especially the role of each component in the resulting aggregate morphology. This network structure can be of major importance for the metal and metalloid sorption processes. We synthesized an aggregate model of nanoparticles by varying the Fe/organic carbon (OC) ratio (R). By coupling small-angle neutron and X-ray scattering (SANS, SAXS), dynamic light scattering (DLS), transmission electron microscopy (TEM) and X-ray absorption spectroscopy (XAS), we revealed the fractal organization of Fe (i.e. primary beads forming a nanoparticle called an intermediate aggregate and then forming a secondary aggregate of nanoparticles). As the aggregate size increases with R, the As adsorption rate increases at a constant As/Fe ratio. Two hypotheses were considered: with increasing R, i) the repulsion interactions between the nanoparticles increase, inducing a structure opening, and ii) the Fe part size increases more strongly and is more ramified than the OM part, leading to a decrease of the coating by OM. Both hypotheses involve an increase in the number of available As binding sites. This study offers new perspectives on the impact of the network structure of heterogeneous nano-aggregates on their sorption capacity and could explain some metal/metalloid sorption variations observed in natural samples with variations in Fe/OC ratios.
Published: 2017
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50. Effect of aging and alkali activator on the porous structure of a geopolymer

Author: Jacques Jestin, Prune Steins, Sylvie Rossignol, David Lambertin, Arnaud Poulesquen, Fabien Frizon, Olivier Diat, Jérémy Causse, Département d'études du Traitement et du Conditionnement des Déchets (DTCD), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Laboratoire d'Etudes de l'Enrobage des Déchets (L2ED), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'energie Atomique et aux Energies Alternatives, Ions aux Interfaces Actives (L2IA), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Nanomatériaux pour l'Energie et le Recyclage (LNER), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: porosity, Materials science, Mineralogy, small- and wide-angle X-ray scattering, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, alkali activators, General Biochemistry, Genetics and Molecular Biology, geopolymers, Aluminosilicate, Specific surface area, Porosity, Metakaolin, nitrogen sorption, small-angle neutron scattering, aging, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Alkali metal, Microstructure, Small-angle neutron scattering, 0104 chemical sciences, Geopolymer, Chemical engineering, 0210 nano-technology
Abstract: International audience; Nitrogen sorption and small- and wide-angle X-ray and neutron scattering techniques were used to study the porous structure of geopolymers, inorganic polymers synthesized by reaction of a strongly alkaline solution and an aluminosilicate source (metakaolin). The effects of aging and the use of alkali activators (Na+, K+) of different sizes were investigated at room temperature. The influence of aging time on the microstructure of both geopolymer matrixes was verified in terms of pore volume and specific surface area. The results suggested a refinement of the porosity and therefore a reduction in the pore volume over time. Regardless of the age considered, some characteristics of the porous network such as pore size, shape and distribution depend on the alkali activator used. Whatever the technique considered, the potassium geopolymer has a greater specific surface area than the sodium geopolymer. According to the scattering results, the refinement of the porosity can be associated with, first, a densification of the solid network and, secondly, a partial closure of the porosity at the nanometre scale. The kinetics are much slower for the sodium geopolymer than for the potassium geopolymer in the six months of observation. © 2014 International Union of Crystallography.
Published: 2014
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