28 results on '"Emo M"'
Search Results
2. Effect of Zn on magnetic and magnetocaloric properties in (0.75)La0.62Nd0.05Ba0·33MnO3/(0.25)Ni1-xZnxFe2O4 composites
- Author
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Tillaoui, S., Rabi, B., Sajieddine, M., Essoumhi, A., Emo, M., El Boubekri, A., Lassri, M., Hlil, E.K., Sahlaoui, M., and Razouk, A.
- Published
- 2024
- Full Text
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3. Influence of Al3+ substituted cobalt nano-ferrite on structural, morphological and magnetic properties
- Author
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Ounacer, M., Rabi, B., Essoumhi, A., Sajieddine, M., Costa, B.F.O., Emo, M., Razouk, A., and Sahlaoui, M.
- Published
- 2021
- Full Text
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4. CO2 outperforms KOH as an activator for high-rate supercapacitors in aqueous electrolyte
- Author
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Castro-Gutiérrez, J., primary, Canevesi, R.L.S., additional, Emo, M., additional, Izquierdo, M.T., additional, Celzard, A., additional, and Fierro, V., additional
- Published
- 2022
- Full Text
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5. Nano-diamants purifiés pour des réflecteurs de neutrons lents nouvelle génération
- Author
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Henry, K., Emo, M., Gaudisson, T., Pischedda, V., Floch, S. Le, Nesvizhevsky, V., Zhernenkov, K., Bosak, A., Vigolo, B., Dubois, M., Institut de Chimie de Clermont-Ferrand (ICCF), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national polytechnique Clermont Auvergne (INP Clermont Auvergne), and Université Clermont Auvergne (UCA)-Université Clermont Auvergne (UCA)
- Subjects
[CHIM]Chemical Sciences - Abstract
International audience
- Published
- 2022
6. Selective combustion of detonation nanodiamonds: a useful approach to evaluate the undesired metallic impurities
- Author
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Henry, K., Emo, M., Diliberto, S., Arnault, J.-C., Girard, H.A., Nesvizhevsky, V., Vigolo, B., Dubois, M., Institut de Chimie de Clermont-Ferrand (ICCF), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national polytechnique Clermont Auvergne (INP Clermont Auvergne), and Université Clermont Auvergne (UCA)-Université Clermont Auvergne (UCA)
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[CHIM]Chemical Sciences - Abstract
International audience
- Published
- 2022
7. Unveiling the metallic impurities in detonation nanodiamond by a total oxidation treatment
- Author
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Henry, K., Emo, M., Diliberto, S., Arnault, J.-C., Girard, H.A., Nesvizhevsky, V., Vigolo, B., Dubois, M., Institut de Chimie de Clermont-Ferrand (ICCF), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national polytechnique Clermont Auvergne (INP Clermont Auvergne), and Université Clermont Auvergne (UCA)-Université Clermont Auvergne (UCA)
- Subjects
[CHIM]Chemical Sciences - Abstract
International audience
- Published
- 2022
8. New generation of slow neutron reflectors using purified nanodiamonds
- Author
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Henry, K., EMO, M., GAUDISSON, T., PISCHEDDA, V., FLOCH, S. LE, Nesvizhevsky, V., Bosak, A., VIGOLO, B., Dubois, M., Bonnefoy, Stéphanie, Institut de Chimie de Clermont-Ferrand (ICCF), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national polytechnique Clermont Auvergne (INP Clermont Auvergne), and Université Clermont Auvergne (UCA)-Université Clermont Auvergne (UCA)
- Subjects
[CHIM] Chemical Sciences ,[CHIM]Chemical Sciences ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2021
9. Low-Temperature Growth of AlN Films on Magnetostrictive Foils for High-Magnetoelectric-Response Thin-Film Composites
- Author
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Nguyen, T., Fleming, Y., Bender, P., Grysan, P., Valle, N., El Adib, B., Adjeroud, N., Arl, D., Emo, M., Ghanbaja, J., Michels, Andreas, Polesel-Maris, J., Nguyen, T., Fleming, Y., Bender, P., Grysan, P., Valle, N., El Adib, B., Adjeroud, N., Arl, D., Emo, M., Ghanbaja, J., Michels, Andreas, and Polesel-Maris, J.
- Published
- 2021
10. Large-magnitude (VEI ≥ 7) ‘wet’ explosive silicic eruption preserved a Lower Miocene habitat at the Ipolytarnóc Fossil Site, North Hungary
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Dávid Karátson, Tamás Biró, Maxim Portnyagin, Balázs Kiss, Jean-Louis Paquette, Zoltán Cseri, Mátyás Hencz, Károly Németh, Pierre Lahitte, Emő Márton, László Kordos, Sándor Józsa, Lilla Hably, Samuel Müller, and Imre Szarvas
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Medicine ,Science - Abstract
Abstract During Earth’s history, geosphere-biosphere interactions were often determined by momentary, catastrophic changes such as large explosive volcanic eruptions. The Miocene ignimbrite flare-up in the Pannonian Basin, which is located along a complex convergent plate boundary between Europe and Africa, provides a superb example of this interaction. In North Hungary, the famous Ipolytarnóc Fossil Site, often referred to as “ancient Pompeii”, records a snapshot of rich Early Miocene life buried under thick ignimbrite cover. Here, we use a multi-technique approach to constrain the successive phases of a catastrophic silicic eruption (VEI ≥ 7) dated at 17.2 Ma. An event-scale reconstruction shows that the initial PDC phase was phreatomagmatic, affecting ≥ 1500 km2 and causing the destruction of an interfingering terrestrial–intertidal environment at Ipolytarnóc. This was followed by pumice fall, and finally the emplacement of up to 40 m-thick ignimbrite that completely buried the site. However, unlike the seemingly similar AD 79 Vesuvius eruption that buried Pompeii by hot pyroclastic density currents, the presence of fallen but uncharred tree trunks, branches, and intact leaves in the basal pyroclastic deposits at Ipolytarnóc as well as rock paleomagnetic properties indicate a low-temperature pyroclastic event, that superbly preserved the coastal habitat, including unique fossil tracks.
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- 2022
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11. Limit of Miscibility and Nanophase Separation in Associated Mixtures
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Artola, P. A., primary, Raihane, A., additional, Crauste-Thibierge, C., additional, Merlet, D., additional, Emo, M., additional, Alba-Simionesco, C., additional, and Rousseau, B., additional
- Published
- 2013
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12. Triblock Siloxane Copolymer Surfactant: Template for Spherical Mesoporous Silica with a Hexagonal Pore Ordering
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Stébé, M. J., primary, Emo, M., additional, Forny-Le Follotec, A., additional, Metlas-Komunjer, L., additional, Pezron, I., additional, and Blin, J. L., additional
- Published
- 2013
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13. New paleomagnetic results from imbricated Adria: Ist Island and related areas
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Emo Marton and Alan Moro
- Subjects
imbricated Adria, paleomagnetism, Late Cretaceous ,Geology ,QE1-996.5 - Abstract
For the purpose of this work samples for palaeomagnetic analysis were taken from Upper Cenomanian and Lower Senonian shallow water limestones, as well as from Senonian pelagic limestones from both Ist and the surrounding islands. This area belongs to Imbricated Adria, which is characterized by gently folded and faulted strata with a Dinaridic (NW–SE) trend. An exception is Premuda island where the beds are strongly folded and are subvertical. A total of 96 samples were drilled from 10 localities distributed between eight islands. The samples were then subjected to standard palaeomagnetic laboratory analysis and statistical evaluation. Eventually, six localities yielded statistically well-defined palaeomagnetic directions, which were shown pre date the folding in age.The overall mean palaeomagnetic direction obtained for the study area, characterizing the Cenomanian–Early Senonian time period had a Declination of 334°, Inclination=+46°, with statistical parameters k=188, a95=4.9°, defining a palaeomagnetic pole at l(N)=63°, f(E)=254°, dp=4.0°, dm=6.2°. This was compared with palaeomagnetic directions obtained for rocks of similar ages from stable Istria and the Kvarner islands. As the three palaeomagnetic directions are statistically identical, we conclude that there was no significant relative movement between the three areas after the Early Senonian. The palaeomagnetic declination for the study area, which characterizes the post-Early Senonian rotation of the Adriatic microplate, is the same as the declination for the Pannonian–Pontian age group from the South Pannonian basin. As the palaeomagnetic signals in both cases are primary, the results of the present paper not only support the conclusion that the rotating Adriatic microplate triggered rotations in the South Pannonian basin, but also suggest that the Adriatic platform did not change its orientation between the late Cretaceous and the Early Pontian.
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- 2009
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14. Miocene to Quaternary deformation, stratigraphy and paleogeography in Northeastern Slovenia and Southwestern Hungary
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Laszlo Fodor, Bogoljub Jelen, Emo Marton, Helena Rifelj, Marijan Kraljić, Renata Kervić, Peter Marton, Balazs Koroknai, and Maria Baldi-Beke
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faulting ,folding ,subsidence ,uplift ,paleomagnetism ,rotation ,paleostress ,depositional environment ,Neogene ,Pannonian basin ,Slovenia ,SW Hungary ,Geology ,QE1-996.5 - Abstract
The Mura-Zala basin was formed due to ENE-WSW trending crustal extension in the late early and middle Miocene (19 – 11 Ma). Marine sedimentation occurred in several more or less confined depressions (half grabens), then in a unified basin. The rifting phasewas probably connected to uplift and brittle-ductile deformation of metamorphic basement at the eastern part of the Pohorje and Kozjak hills. During the late Miocene thermal subsidence, deltaic to fluvial sediments were deposited.After sedimentation, the southernmost Haloze-Budafa sub-basin was inverted. Mapscale folds, reverse and strike-slip faults were originated by NNW-SSE compression during the latest Miocene(?)–Pliocene. After this folding, Karpatian sediments of theHaloze acquired magnetization. During the late(?)Pliocene to Quaternary(?), the whole Mura-Zala basin, including the folded Haloze, suffered 30° counterclockwise rotation as a relatively rigid block. This rotation affected a wider area from Slovenia to western Hungary and northern Croatia.
- Published
- 2002
15. Paleomagnetic, Tectonic and Stratigraphic Correlation of Tertiary Formations in Slovenia and Hungary along the Periadriatic and Mid-Hingarian Tectonic Zone (Preliminary Communication)
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Bogomir Jelen, Emo Marton, Laszlo Fodor, Maria Baldi, Jože Čar, Helena Rifelj, Dragomir Skaberne, and Marko Vrabec
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Palemagnetism ,structural geology ,tectonics ,stratigraphy ,Tertiary ,Slovenia ,Hungary ,Geology ,QE1-996.5 - Published
- 1997
16. Inequalities in neighbourhood socioeconomic characteristics: potential evidence-base for neighbourhood health planning
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Hutchison Brian, Birch Stephen, Emo Marion, Wray Ron, Odoi Agricola, Eyles John, and Abernathy Tom
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Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
Abstract Background Population health planning aims to improve the health of the entire population and to reduce health inequities among population groups. Socioeconomic factors are increasingly being recognized as major determinants of many aspects of health and causes of health inequities. Knowledge of socioeconomic characteristics of neighbourhoods is necessary to identify their unique health needs and enhance identification of socioeconomically disadvantaged populations. Careful integration of this knowledge into health planning activities is necessary to ensure that health planning and service provision are tailored to unique neighbourhood population health needs. In this study, we identify unique neighbourhood socioeconomic characteristics and classify the neighbourhoods based on these characteristics. Principal components analysis (PCA) of 18 socioeconomic variables was used to identify the principal components explaining most of the variation in socioeconomic characteristics across the neighbourhoods. Cluster analysis was used to classify neighbourhoods based on their socioeconomic characteristics. Results Results of the PCA and cluster analysis were similar but the latter were more objective and easier to interpret. Five neighbourhood types with distinguishing socioeconomic and demographic characteristics were identified. The methodology provides a more complete picture of the neighbourhood socioeconomic characteristics than when a single variable (e.g. income) is used to classify neighbourhoods. Conclusion Cluster analysis is useful for generating neighbourhood population socioeconomic and demographic characteristics that can be useful in guiding neighbourhood health planning and service provision. This study is the first of a series of studies designed to investigate health inequalities at the neighbourhood level with a view to providing evidence-base for health planners, service providers and policy makers to help address health inequity issues at the neighbourhood level. Subsequent studies will investigate inequalities in health outcomes both within and across the neighbourhood types identified in the current study.
- Published
- 2005
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17. NiCo2O4 nanostructures loaded onto pencil graphite rod: An advanced composite material for oxygen evolution reaction
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Zafar Hussain Ibupoto, Aneela Tahira, Aqeel Ahmed Shah, Umair Aftab, Muhammad Yameen Solangi, Jaleel Ahmed Leghari, Abdul Hanan Samoon, Adeel Liaquat Bhatti, Muhammad Ali Bhatti, Raffaello Mazzaro, Vittorio Morandi, Muhammad Ishaq Abro, Ayman Nafady, Abdullah M. Al-Enizi, Mélanie Emo, Brigitte Vigolo, Ibupoto Z.H., Tahira A., Shah A.A., Aftab U., Solangi M.Y., Leghari J.A., Samoon A.H., Bhatti A.L., Bhatti M.A., Mazzaro R., Morandi V., Abro M.I., Nafady A., Al-Enizi A.M., Emo M., Vigolo B., and University of Sindh Jamshoro
- Subjects
Metal oxide ,Oxygen evolution reaction ,Renewable Energy, Sustainability and the Environment ,MgO ,Energy Engineering and Power Technology ,[CHIM.MATE]Chemical Sciences/Material chemistry ,[CHIM.CATA]Chemical Sciences/Catalysis ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,7. Clean energy ,Pencil graphite rod ,0104 chemical sciences ,Fuel Technology ,SiO ,0210 nano-technology ,ComputingMilieux_MISCELLANEOUS - Abstract
Driving oxygen evolution reaction (OER) at extremely low overpotential and the blockage of oxygen gas inside the catalytic material leads to the deactivation of catalytic activity, therefore it is an essential step in electrochemical energy conversion systems, but still very challenging task. The clay minerals including bentonite and kaolinite are rich with plenty of active centers and favorable chemical composition for the catalysis applications but limited by the insulating properties, thus they cannot be used as an electrode material for the water splitting. The unique presence of clay minerals in the form of pencil graphite rod (PGR) and its attractive architecture enabled us to exploit advantageous features and use them as an in situ electrode for growth of metal oxide nanostructures for the electrolysis applications. The naturally inherent presence of SiO2 favors the catalytic properties and durability of the electrode whereas the MgO produces the abundant oxygen vacancies and Co3+ ions for OER process. Herein, we present a facile approach of using PGR as host substrate and co-catalyst for the loading of Co3O4, NiCo2O4 and NiO nanostructures and the modified electrode carried high porosity for easily bubbling of oxygen gas, plenty of intrinsic active centers coming from both clay minerals and metal oxides for excellent OER process. The fabricated electrode is physically well-characterized, and it has a natural ability to sustain a long term stability even at higher current densities and industrial electrolyzer conditions. The NiCo2O4/PGR, Co3O4/PGR, and NiO/PGR electrodes exhibit an overpotential of 234, 242 and 272 mV respectively at a current density of 100 mAcm−2 in 1.0 M KOH electrolytic solution. The presence of large number of oxygen vacancies through SiO2 and MgO, high Ni2+/Ni3+ and Co3+/Co2+ ratios, multi metal centers, large specific surface area, high pore volume, high electrochemical active surface area and fast charge transport within the NiCo2O4/PGR are the main reasons for its superfast OER kinetics. Thus, the proposed method of electrode design will pave a potential way for high performance electrochemical devices like metal air batteries, fuel cell and supercapacitors.
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- 2022
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18. Modulating the Iron Microenvironment for a Cooperative Interplay Between Fe-N-C Single Atoms and Fe 3 C Nanoclusters on the Oxygen Reduction Reaction.
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Dessalle A, Quílez-Bermejo J, Hounfodji JW, Badawi M, Zitolo A, Emo M, Izquierdo MT, Xu F, Fierro V, and Celzard A
- Abstract
The coexistence of single atoms and nanoparticles is shown to increase the oxygen reduction performance in Fe-N-C electrocatalysts, but the mechanisms underlying this synergistic effect remain elusive. In this study, model Fe-N-C electrocatalysts with controlled ratios of FeN
4 sites and Fe3 C nanoclusters is systematically designed and synthesized. Experiments and density functional theory (DFT) computations reveal that Fe3 C nanoclusters near FeN4 sites modulate the electron density of the Fe single-atom microenvironment through an electron withdrawing effect. This substantially alters the oxygen reduction reaction (ORR) mechanisms and boosts the catalytic performance of FeN4 sites. This study provides fundamental insights into the dynamic catalytic impact of single atoms and nanoparticle coexistence in advanced Fe-N-C electrocatalysts for the ORR, paving the way for further refinement through various combinations., (© 2024 Wiley‐VCH GmbH.)- Published
- 2025
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19. Transforming NiCo 2 O 4 nanorods into nanoparticles using citrus lemon juice enhancing electrochemical properties for asymmetric supercapacitor and water oxidation.
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Kumar S, Tahira A, Bhatti AL, Bhatti MA, Mari RH, Shaikh NM, Solangi MY, Nafady A, Emo M, Vigolo B, Infantes-Molina A, Vomiero A, and Ibupoto ZH
- Abstract
Recently, the nanostructured nickel-cobalt bimetallic oxide (NiCo
2 O4 ) material with high electrochemical activity has received intensive attention. Beside this, the biomass assisted synthesis of NiCo2 O4 is gaining popularity due to its advantageous features such as being low cost, simplicity, minimal use of toxic chemicals, and environment-friendly and ecofriendly nature. The electrochemical activity of spinel NiCo2 O4 is associated with its mixed metal oxidation states. Therefore, much attention has been paid to the crystal quality, morphology and tunable surface chemistry of NiCo2 O4 nanostructures. In this study, we have used citrus lemon juice consisting of a variety of chemical compounds having the properties of a stabilizing agent, capping agent and chelating agent. Moreover, the presence of several acidic chemical compounds in citrus lemon juice changed the pH of the growth solution and consequently we observed surface modified and structural changes that were found to be very effective for the development of energy conversion and energy storage systems. These naturally occurring compounds in citrus lemon juice played a dynamic role in transforming the nanorod morphology of NiCo2 O4 into small and well-packed nanoparticles. Hence, the prepared NiCo2 O4 nanostructures exhibited a new surface-oriented nanoparticle morphology, high concentration of defects on the surface (especially oxygen vacancies), sufficient ionic diffusion and reaction of electrolytic ions, enhanced electrical conductivity, and favorable reaction kinetics at the interface. The electrocatalytic properties of the NiCo2 O4 nanostructures were studied in oxygen evolution reaction (OER) at a low overpotential of 250 mV for 10 mA cm-2 , Tafel slope of 98 mV dec-1 , and durability of 40 h. Moreover, an asymmetric supercapacitor was produced and the obtained results indicated a high specific capacitance of ( Cs ) of 1519.19 F g-1 , and energy density of 33.08 W h kg-1 at 0.8 A g-1 . The enhanced electrochemical performance could be attributed to the favorable structural changes, surface modification, and surface crystal facet exposure due to the use of citrus lemon juice. The proposed method of transformation of nanorod to nanoparticles could be used for the design of a new generation of efficient electrocatalyst materials for energy storage and conversion uses., Competing Interests: Authors declare no conflict of interest in this research work., (This journal is © The Royal Society of Chemistry.)- Published
- 2023
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20. A green approach for the preparation of ZnO@C nanocomposite using agave americana plant extract with enhanced photodegradation.
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Jakhrani MA, Tahira A, Bhatti MA, Shah AA, Shaikh NM, Mari RH, Vigolo B, Emo M, Albaqami MD, Nafady A, and Ibupoto ZH
- Subjects
- Carbon, Catalysis, Photolysis, Plant Extracts chemistry, Rosaniline Dyes, Agave, Nanocomposites, Zinc Oxide chemistry
- Abstract
The present study demonstrates the crucial role of agave americana extract in enhancing the optical properties of zinc oxide (ZnO) through thermal treatment method. Various analytical and surface science techniques have been used to identify the morphology, crystalline structure, chemical composition, and optical properties, including scanning electron microscopy, x-ray diffraction, high resolution transmission electron microscopy (HRTEM), x-ray spectroscopy (EDS) and UV-visible spectroscopy techniques. The physical studies revealed the transformation of ZnO nanorods into nanosheets upon addition of an optimized amount of agave americana extract, which induced large amount of amorphous carbon deposited onto ZnO nanostructures as confirmed by HRTEM analysis. The use of increasing amount of americana extract has significantly reduced the average crystallite size of ZnO nanostructures. The resultant hybrid system of C@ZnO has produced a significant effect on the ultraviolet light-assisted photodegradation of malachite green (MG) dye. The photocatalyst dose was fixed at 10 mg for each study whereas the amount of agave americana extract and MG dye concentration are varied. The functionality of hybrid system was greatly enhanced when the amount of agave americana extract increased while dye concentration kept at lower level. Ultimately, almost 100% degradation efficiency was achieved via the prepared hybrid material, revealing combined contribution from synergy, stabilization of ZnO due to excess of carbon together with the high charge separation rate. The obtained results suggest that the driving role of agave americana extract for surface modification of photocatalyst can be considered for other nanostructured photocatalysts., (© 2022 IOP Publishing Ltd.)
- Published
- 2022
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21. Optimized ICPCVD-Based TiO 2 for Photonics.
- Author
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Andrieux A, Mennemanteuil MM, Geoffroy N, Emo M, Markey L, and Hammani K
- Abstract
We propose obtaining TiO
2 films by ICPCVD for the fabrication of low-loss waveguides. The challenge is to produce a dense and homogeneous layer with a high refractive index and low absorption in the visible range. Crystallized layers with features such as grains and amorphous layers have a rather low index for the application targeted, so we aimed for an intermediate state. We investigated the influence of plasma power, pressure, deposition time and annealing temperature on the structural, crystalline, and optical properties in order to tailor them. We showed that crystallization into rutile at the nanoscale occurred during deposition and under wisely chosen conditions, we reached a refractive index of 2.5 at 630 nm without creating interfaces or inhomogeneity in the layer depth. Annealing permits one to further increase the index, up to 2.6. TEM analysis on one sample before and after annealing confirmed the nano-polycrystallization and presence of both anatase and rutile phases and we considered that this intermediate state of crystallization was the best compromise for guided optics.- Published
- 2022
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22. Physical and Chemical Activation of Graphene-Derived Porous Nanomaterials for Post-Combustion Carbon Dioxide Capture.
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Firdaus RM, Desforges A, Emo M, Mohamed AR, and Vigolo B
- Abstract
Activation is commonly used to improve the surface and porosity of different kinds of carbon nanomaterials: activated carbon, carbon nanotubes, graphene, and carbon black. In this study, both physical and chemical activations are applied to graphene oxide by using CO
2 and KOH-based approaches, respectively. The structural and the chemical properties of the prepared activated graphene are deeply characterized by means of scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectrometry and nitrogen adsorption. Temperature activation is shown to be a key parameter leading to enhanced CO2 adsorption capacity of the graphene oxide-based materials. The specific surface area is increased from 219.3 m2 g-1 for starting graphene oxide to 762.5 and 1060.5 m2 g-1 after physical and chemical activation, respectively. The performance of CO2 adsorption is gradually enhanced with the activation temperature for both approaches: for the best performances of a factor of 6.5 and 9 for physical and chemical activation, respectively. The measured CO2 capacities are of 27.2 mg g-1 and 38.9 mg g-1 for the physically and chemically activated graphene, respectively, at 25 °C and 1 bar.- Published
- 2021
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23. Low-Temperature Growth of AlN Films on Magnetostrictive Foils for High-Magnetoelectric-Response Thin-Film Composites.
- Author
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Nguyen T, Fleming Y, Bender P, Grysan P, Valle N, El Adib B, Adjeroud N, Arl D, Emo M, Ghanbaja J, Michels A, and Polesel-Maris J
- Abstract
This study reports a strong ME effect in thin-film composites consisting of nickel, iron, or cobalt foils and 550 nm thick AlN films grown by PE-ALD at a (low) temperature of 250 °C and ensuring isotropic and highly conformal coating profiles. The AlN film quality and the interface between the film and the foils are meticulously investigated by means of high-resolution transmission electron microscopy and the adhesion test. An interface (transition) layer of partially amorphous Al
x Oy /AlOx Ny with thicknesses of 10 and 20 nm, corresponding to the films grown on Ni, Fe, and Co foils, is revealed. The AlN film is found to be composed of a mixture of amorphous and nanocrystalline grains at the interface. However, its crystallinity is improved as the film grew and shows a highly preferred (002) orientation. High self-biased ME coefficients (αME at a zero-bias magnetic field) of 3.3, 2.7, and 3.1 V·cm-1 ·Oe-1 are achieved at an off-resonance frequency of 46 Hz in AlN/Ni thin-film composites with different Ni foil thicknesses of 7.5, 15, and 30 μm, respectively. In addition, magnetoelectric measurements have also been carried out in composites made of 550 nm thick films grown on 12.5 μm thick Fe and 15 μm thick Co foils. The maximum magnetoelectric coefficients of AlN/Fe and AlN/Co composites are 0.32 and 0.12 V·cm-1 ·Oe-1 , measured at 46 Hz at a bias magnetic field ( Hdc ) of 6 and 200 Oe, respectively. The difference of magnetoelectric transducing responses of each composite is discussed according to interface analysis. We report a maximum delivered power density of 75 nW/cm3 for the AlN/Ni composite with a load resistance of 200 kΩ to address potential energy harvesting and electromagnetic sensor applications.- Published
- 2021
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24. Investigation of mixed ionic/nonionic building blocks for the dual templating of macro-mesoporous silica.
- Author
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Roucher A, Emo M, Vibert F, Stébé MJ, Schmitt V, Jonas F, Backov R, and Blin JL
- Abstract
Traditional porous monoliths Si(HIPE) (High Internal Phase Emulsion), prepared from the Tetradecyltrimethylammonium Bromide (TTAB)/dodecane/water system, offer high specific surface area, mainly due to microporosity. Aside, mesoporous materials SBA-15, prepared from Pluronic P123, have a high specific surface area, but are obtained as powder, which limits their applications. Starting from the mixed TTAB-P123 surfactant, it is expected to tune the mesoporosity of Si(HIPE), while keeping their monolithic character. The ternary TTAB/P123/water phase diagram was established by varying the weight ratio between these two surfactants. The micellar structure as well as the structural parameters of the liquid crystal domains were determined by SAXS (Small Angle X-ray Scattering). The effect of dodecane solubilization was also investigated and concentrated emulsions were formulated from the (P123/TTAB)/dodecane/water systems. After this soft matter dedicated study, the acquired knowledge was transferred toward the hierarchical porous silica generations, where the sol-gel process is involved. Mixing P123 with TTAB, macro-mesoporous monolithic silica with an enhanced contribution of the specific surface area due to mesoporosity can be prepared. The variation of the TTAB/P123 weight ratio allows controlling the porosity at the mesoscale. Moreover, the macroporosity can be tuned by changing the preparation method, by mixing either the two micellar solutions or directly the two surfactants prior the emulsification process., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2019
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25. Investigation of a novel fluorinated surfactant-based system for the design of spherical wormhole-like mesoporous silica.
- Author
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Riachy P, Lopez G, Emo M, Stébé MJ, Blin JL, and Ameduri B
- Abstract
In contrast to hydrogenated based systems that led to many studies, fluorinated surfactants have been little reported. Thanks to their high chemical and thermal stability, these compounds are considered as suitable candidates for the synthesis of porous materials with an enhanced hydrothermal stability. This study reports the synthesis of a new fluorinated surfactant, 2-trifluoromethyl-7,7,8,8,9,9,10,10,11,11,12,12,12-tridecafluoro-4-thia-1-dodecanoic acid (FSC) obtained from the thiol-ene radical addition of 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-1-octanethiol onto 2-trifluoromethyl acrylic acid in 85% yield. In the aim of achieving micelles in water to design mesoporous materials according to the cooperative templating mechanism, FSC was modified with water-soluble telechelic diamine (Jeffamine) ED-600. The modified surfactant was deeply characterized by spectroscopic methods and the FSC-Jeffamine ED-600 micellar system was used as porogen to prepare mesoporous materials via the cooperative templating mechanism. Spherical wormhole-like mesostructured silica materials of high specific surface area (850m
2 /g) and homogeneous pore size distribution (ca. 3.4nm) were obtained by conveniently adjusting the porogen/silica molar ratio and the hydrothermal conditions., (Copyright © 2016 Elsevier Inc. All rights reserved.)- Published
- 2017
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26. Monoolein Cubic Phase Gels and Cubosomes Doped with Magnetic Nanoparticles-Hybrid Materials for Controlled Drug Release.
- Author
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Szlezak M, Nieciecka D, Joniec A, Pękała M, Gorecka E, Emo M, Stébé MJ, Krysiński P, and Bilewicz R
- Subjects
- Drug Liberation, Gels, Glycerides, Scattering, Small Angle, X-Ray Diffraction, Magnetite Nanoparticles
- Abstract
Hybrid materials consisting of a monoolein lipidic cubic phase (LCP) incorporating two types of magnetic nanoparticles (NP) were designed as addressable drug delivery systems. The materials, prepared in the form of a gel, were subsequently used as a macroscopic layer modifying an electrode and, after dispersion to nanoscale, as magnetocubosomes. These two LCPs were characterized by small-angle X-ray scattering (SAXS), cross-polarized microscopy, magnetic measurements, and phase diagrams. The magnetic dopants were hydrophobic NP
oleic and hydrophilic NPcitric , characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM), and their influence on the properties of the cubic phases was investigated. The removal of the anticancer drug, Doxorubicin (Dox) from the hybrid cubic phase gels was studied by electrochemical methods. The advantages of incorporating magnetic nanoparticles into the self-assembled lipid liquid crystalline phases include the ability to address the cubic phase nanoparticle containing large amounts of drug and to control the kinetics of the drug release.- Published
- 2017
- Full Text
- View/download PDF
27. Role of Solvent and Effect of Substituent on Azobenzene Isomerization by Using Room-Temperature Ionic Liquids as Reaction Media.
- Author
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Angelini G, Canilho N, Emo M, Kingsley M, and Gasbarri C
- Subjects
- Imidazoles chemistry, Oxidation-Reduction, Temperature, Azo Compounds chemistry, Ionic Liquids chemistry, Solvents chemistry
- Abstract
The effects of a para substituent, as the electron-donating -OCH3 and -OtBu groups and the electron-withdrawing -Br and -F atoms, on azobenzene isomerization have been investigated in a series of imidazolium ionic liquids (BMIM PF6, BMIM BF4, BMIM Tf2N, EMIM Tf2N, BM2IM Tf2N, and HMIM Tf2N). The thermal cis-trans conversion tends to be improved in the presence of the substituent, as pointed out by the first-order rate constants measured at 25 °C. Both the rotation and the inversion mechanisms occur in BMIM Tf2N, EMIM Tf2N, and HMIM Tf2N, as highlighted by typical V-shape Hammett plots, but only rotation takes place in BMIM PF6, BMIM BF4, and BM2IM Tf2N. The possible interactions between the cation and the anion of the solvent and both the isomers of the azobenzene derivatives have been studied by small-wide-angle X-ray scattering (SWAXS). The calculated cis population in the photostationary state and the hardness parameter η of the trans isomer show that azobenzene and F-azobenzene are the less reactive molecules for the trans-cis conversion in all the investigated ionic liquids.
- Published
- 2015
- Full Text
- View/download PDF
28. Investigation of mixed fluorinated and triblock copolymer liquid crystals: imprint for mesostructured bimodal silica.
- Author
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Assaker K, Naboulsi I, Stébé MJ, Emo M, and Blin JL
- Subjects
- Adsorption, Ether chemistry, Halogenation, Microscopy, Electron, Scanning, Microscopy, Electron, Transmission, Poloxalene chemistry, Polyethylene Glycols chemistry, Porosity, Scattering, Small Angle, Surface Properties, Surface-Active Agents chemistry, X-Ray Diffraction, Hydrocarbons, Fluorinated chemistry, Liquid Crystals chemistry, Molecular Imprinting, Polymers chemistry, Silicon Dioxide chemistry
- Abstract
Due to the difference in «mutual phobicity» between fluorocarbon and hydrocarbon chains, mixtures of fluorinated and hydrogenated surfactants are excellent candidates to design bimodal systems having two types of mesopores. In literature, only a few papers deal with these bimodal systems. Here hexagonal liquid crystal mixtures of the polyoxyethylene fluoroalkyl ether [R(F)8(EO)9] and the Pluronic [P123] have been used to template this kind of mesostructure through the liquid crystal mechanism, which is barely considered. After the detailed investigation of the R(F)8(EO)9/P123/water liquid crystal domain, materials have been synthesized and characterized by small angle X-ray scattering, transmission electron microscopy and nitrogen adsorption-desorption analysis. Our results show that this system provides two separate pore sizes in the materials over the mesoporous range. The ratio between the small mesopores and the large ones depends on the proportion between the porogens in the mixture. Nonetheless, we also outline that a minimum quantity of silica is required to recover the two hexagonal networks., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
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