CNRS Materials Sciences and Technologies Laboratory

Lyon, France

CNRS Materials Sciences and Technologies Laboratory

Lyon, France
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Demirci U.B.,CNRS Materials Sciences and Technologies Laboratory | Demirci U.B.,Charles Gerhardt Institute | Miele P.,Charles Gerhardt Institute
Energy and Environmental Science | Year: 2011

Chemical hydrogen storage materials (CHSMs), owing to their high hydrogen content, are presented as having high potential to achieve high gravimetric hydrogen storage capacities in the prospect of technological applications (e.g. vehicle). However, this raises two questions. Is the storage capacity viewed at the material level or at the system level? Do we talk about absolute, excess or net capacities? Being exact in the terms used is all important so the US Department of Energy has set well-defined, precise technical requirements for vehicle application at the system level. This Minireview focuses on the terms that have been used in the open literature to present the storage capacities of the CHSMs. It stands out, through several typical cases, that the terms are generally misused and mislead the reader on the real capacities. For instance, the material level and the system level are often lumped together. Herein, we re-define the much-used terms and expressions, and propose a set of expressions to systematically use in order to avoid any future misuse, misleading terms and misunderstanding. © 2011 The Royal Society of Chemistry.

Canivet J.,CNRS Research on Catalysis and Environment in Lyon | Fateeva A.,CNRS Materials Sciences and Technologies Laboratory | Guo Y.,CNRS Research on Catalysis and Environment in Lyon | Coasne B.,Massachusetts Institute of Technology | Farrusseng D.,CNRS Research on Catalysis and Environment in Lyon
Chemical Society Reviews | Year: 2014

This review article presents the fundamental and practical aspects of water adsorption in Metal-Organic Frameworks (MOFs). The state of the art of MOF stability in water, a crucial issue to many applications in which MOFs are promising candidates, is discussed here. Stability in both gaseous (such as humid gases) and aqueous media is considered. By considering a non-exhaustive yet representative set of MOFs, the different mechanisms of water adsorption in this class of materials are presented: reversible and continuous pore filling, irreversible and discontinuous pore filling through capillary condensation, and irreversibility arising from the flexibility and possible structural modifications of the host material. Water adsorption properties of more than 60 MOF samples are reported. The applications of MOFs as materials for heat-pumps and adsorbent-based chillers and proton conductors are also reviewed. Some directions for future work are suggested as concluding remarks. This journal is © the Partner Organisations 2014.

Lekeufack D.D.,CNRS Materials Sciences and Technologies Laboratory | Brioude A.,CNRS Materials Sciences and Technologies Laboratory
Dalton Transactions | Year: 2012

Red cabbage extract was used as reducing agent and capping agent for the synthesis of gold NPs. The method developed is environmentally friendly and allows the control of NPs shape and size by changing the pH value and the concentration of aqueous red cabbage extract solution. © 2012 The Royal Society of Chemistry.

Demirci U.B.,CNRS Materials Sciences and Technologies Laboratory | Miele P.,CNRS Materials Sciences and Technologies Laboratory
Journal of Power Sources | Year: 2010

Ammonia borane NH3BH3 is a promising hydrogen storage material by virtue of a theoretical gravimetric hydrogen storage capacity (GHSC) of 19.5 wt%. However, stored hydrogen has to be effectively released, one way of recovering this hydrogen being the metal-catalyzed hydrolysis. The present study focuses on CoCl2-catalyzed hydrolysis of NH3BH3 with the concern of improving the effective GHSC of the system NH3BH3-H2O. For that, NH3BH3 is stored as a solid and H2O is provided in stoichiometric amount. By this way, an effective GHSC of 7.8 wt% has been reached at 25 °C. To our knowledge, it is the highest value ever reported. Besides, one of the highest hydrogen generation rates (HGRs, 21 ml(H2) min-1) has been found. In parallel, the increases of the water amount and temperature have been studied and the reaction kinetics has been determined. Finally, it has been observed that some NH3 release, what is detrimental for a fuel cell. To summarize, high performances in terms of GHSCs and HGRs can be reached with NH3BH3 and since research devoted to this boron hydride is at the beginning we may be confident in making it viable in a near future. © 2010 Elsevier B.V. All rights reserved.

Perret F.,CNRS Institute of Molecular and Supramolecular Chemistry and Biochemistry | Coleman A.W.,CNRS Materials Sciences and Technologies Laboratory
Chemical Communications | Year: 2011

This review treats the biological properties of the various anionic calix[n]arenes, both as soluble forms and in the collodal state. The complexation of these molecules with amino-acids, peptides and proteins is discussed, as is their interaction with model membranes. The complexations with various Active Pharmaceutical Ingredients as complexes, for tamoxifen as solid state and colloidal structures, are treated in depth. Two sections deal with the direct biological action of the calix[n]arenes and their use as biosensors. A final section deals with the toxicity, in reality the lack of toxicity of the calix[n]arenes. © 2011 The Royal Society of Chemistry.

Dupont C.,French Atomic Energy Commission | Chiriac R.,CNRS Materials Sciences and Technologies Laboratory | Gauthier G.,French Atomic Energy Commission | Toche F.,CNRS Materials Sciences and Technologies Laboratory
Fuel | Year: 2014

This study aims at measuring heat capacity on a large range of biomass types and on pyrolysis chars obtained under conditions representative of industrial reactors for further use of these data in thermal conversion models. As expected, linear increase could be observed with temperature for the 21 biomasses tested between 313 K and 353 K. The relative difference of heat capacity between the different biomasses was significant but lower than 20%, with values ranging from 1300 to 2000 J kg-1 K-1. The sample form, either in block or powder, did not seem to have any influence. Values of about 1000 J kg-1 K-1 were measured on chars, whatever the pyrolysis temperature. These values are in the same order of magnitude as those extrapolated from literature correlations. As expected, linear increase could be observed with temperature, except in the range 353-513 K, in which an exothermal phenomenon of recombination seems to occur inside the char. © 2013 Elsevier Ltd. All rights reserved.

Ferro G.,CNRS Materials Sciences and Technologies Laboratory
Critical Reviews in Solid State and Materials Sciences | Year: 2015

For a long time now, 3C-SiC has attracted attention of the semiconductor community due to its very interesting properties. The lack of commercial 3C-SiC seeds for epitaxy has forced researchers to prospect for different host materials in order to grow heteroepitaxial thin layers. Because of the obvious economical and technical advantages, silicon is a very attractive substrate so that more than 90% of the thin 3C-SiC heteroepitaxial films are grown on such seed. However, the obstacles to overcome, mainly lattice and thermal mismatch, are challenging. This article reviews the numerous attempts for growing high quality 3C-SiC heteroepitaxial layers on silicon substrate. The various aspects of the heteroepitaxial growth, from substrate carbonization to epitaxy, are discussed as a function of growth parameters. The difficulties encountered and the proposed solutions are described. Perspectives of this heteroepitaxial system are proposed. Copyright © 2014 Taylor & Francis Group, LLC.

Ferro G.,CNRS Materials Sciences and Technologies Laboratory
Materials Science Forum | Year: 2010

The objective of this review is to set the present state of the art of 3C-SiC crystalline growth by emphasizing the new and promising trends related to this polytype elaboration. The need of high quality 3C seed is showed to be more important than for other polytypes, in order to avoid β→α transformation during high temperature bulk growth. The effect of various parameters, such as supersaturation, gas phase composition, strain or impurities, is discussed. Recent results obtained using vapour-liquid-solid mechanism and continuous feed vapour phase transport are bringing new insight on 3C-SiC stability and setting new standards of material quality. © (2010) Trans Tech Publications.

Novel boron nitride (BN) fibers have been developed with diameters ranging from the nano- to microscale by thermal conversion of as-electrospun fibers from polyacrylonitrile and poly[B-(methylamino)borazine] blend solutions. Such a new class of ceramic fibers is seen as potential candidate for thermal management applications and filtration systems in harsh environments.

Hu L.,CNRS Materials Sciences and Technologies Laboratory | De Montferrand C.,University of Paris 13 | Lalatonne Y.,University of Paris 13 | Lalatonne Y.,Service Route | And 2 more authors.
Journal of Physical Chemistry C | Year: 2012

In this work, we investigate the effect of cobalt substitution on the size evolution, crystal structure, and magnetic properties of Fe 3O 4 nanoparticles. Monodisperse Co xFe 3-xO 4 nanoparticles were prepared, using a one-step method, by direct heating process of iron(III) and cobalt(II) acetylacetonates in high-boiling-point inert organic solvent. The quantities of precursors added were based on stoichiometric Fe/Co ratio of desired ferrite. Elemental analyses ICP-AES evidenced successful cobalt doping. The doped particles showed a cobalt-deficient composition. Transmission electron microscopy demonstrated the large changes of particle size as a function of cobalt doping. The magnetization measurements showed an unchanged saturation magnetization only up to x = 0.24, beyond which it significantly decreased. To make the as-synthesized nanoparticles suitable for biomedical applications, oleic acid ligands are exchanged with caffeic acid molecules leading to stable nanoparticles in physiological conditions. © 2012 American Chemical Society.

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