Gibot P.,French National Center for Scientific Research |
Vidal L.,CNRS Mulhouse Institute of Materials Science
Journal of the European Ceramic Society | Year: 2010
Nanosized chromium (Cr2O3) oxide was prepared by the common thermal decomposition of Cr(NO3)3·9H2O chromium (III) nitrate nonahydrate. Prior to the heat treatment at 550 °C, the commercial reagent was first dissolved in a colloidal silica solution and then dried at a low temperature to slowly evaporate the aqueous solvent. The SiO2/Cr(NO3)3·9H2O weight ratio (R) was changed from 0 to 2. The various Cr2O3 powders were characterized by XRD, FTIR, nitrogen adsorption, SEM and TEM techniques. A maximum specific surface area of 113 m2 g-1, associated with a pore volume of 0.72 cm3 g-1, was obtained for the Cr2O3 powder prepared with R = 2. These pristine chromium oxide nanoparticles, with a slightly sintered sphere-shaped morphology, exhibited a 10 nm particle size with a monocrystalline character as demonstrated by the TEM and XRD correlation. © 2009 Elsevier Ltd. All rights reserved.
Pan X.,University of Pittsburgh |
Lacote E.,French National Center for Scientific Research |
Lalevee J.,CNRS Mulhouse Institute of Materials Science |
Curran D.P.,University of Pittsburgh
Journal of the American Chemical Society | Year: 2012
Otherwise sluggish or completely ineffective radical reductions of alkyl and aryl halides by N-heterocyclic carbene boranes (NHC-boranes) are catalyzed by thiols. Reductions and reductive cyclizations with readily available 1,3-dimethylimidazol-2-ylidene borane and a water-soluble triazole relative are catalyzed by thiophenol and tert-dodecanethiol [C 9H 19C(CH 3) 2SH]. Rate constants for reaction of the phenylthiyl (PhS•) radical with two NHC-boranes have been measured to be ∼10 8 M -1 s -1 by laser flash photolysis experiments. An analysis of the available evidence suggests the operation of polarity reversal catalysis. © 2012 American Chemical Society.
Pierre Fouassier J.,Upper Alsace University |
Lalevee J.,CNRS Mulhouse Institute of Materials Science
RSC Advances | Year: 2012
Three-component photoinitiating systems of radical and cationic polymerization are reviewed. The involved mechanisms are described. The design of new promising systems for the photopolymerization of low viscosity monomers under air and low intensity light sources (household lamps, LED bulbs, the sun, LEDs, diode lasers) in the 350-700 nm wavelength range suggest novel applications for Radiation Curing, Laser Imaging, optics, holography or medicine areas. © 2012 The Royal Society of Chemistry.
Alonso B.,Charles Gerhardt Institute |
Marichal C.,CNRS Mulhouse Institute of Materials Science
Chemical Society Reviews | Year: 2013
In this tutorial review we intend to give an overview of the potential of NMR spectroscopy, and in particular solid-state NMR, in characterising micelle-templated mesoporous materials. Different topics are covered including the study of formation mechanisms, the characterisation of structures, textures, surfaces and interfaces, functionalisation, dynamic properties and structure-reactivity correlations. Some selected examples illustrate the variety of information provided by this spectroscopy. Particular attention is paid to recent technological and/or methodological developments. © The Royal Society of Chemistry 2013.
Zhao T.,National University of Ireland |
Zheng Y.,National University of Ireland |
Poly J.,CNRS Mulhouse Institute of Materials Science |
Wang W.,National University of Ireland
Nature Communications | Year: 2013
The three-dimensional structures of hyperbranched materials have made them attractive in many important applications. However, the preparation of hyperbranched materials remains challenging. The hyperbranched materials from addition polymerization have gained attention, but are still confined to only a low level of branching and often low yield. Moreover, the complication of synthesis only allows a few specialized monomers and inimers to be used. Here we report a 'Vinyl Oligomer Combination' strategy; a versatile approach that overcomes these difficulties and allows facile synthesis of highly branched polymeric materials from readily available multi-vinyl monomers, which have long been considered as formidable starting materials in addition polymerization. We report the alteration of the growth manner of polymerization by controlling the kinetic chain length, together with the manipulation of chain growth conditions, to achieve veritable hyperbranched materials, which possess nearly 70% branch ratios as well as numerous vinyl functional groups. © 2013 Macmillan Publishers Limited. All rights reserved.
Chatgilialoglu C.,National Research Council Italy |
Lalevee J.,CNRS Mulhouse Institute of Materials Science
Molecules | Year: 2012
This review article focuses on the recent applications of tris(trimethylsilyl)silane as a radical-based reagent in organic chemistry. Numerous examples of the successful use of (TMS)3SiH in radical reductions, hydrosilylation and consecutive radical reactions are given. The use of (TMS) 3SiH allows reactions to be carried out under mild conditions with excellent yields of products and remarkable chemo-, regio-, and stereoselectivity. The strategic role of (TMS) 3SiH in polymerization is underlined with emphasis on the photo-induced radical polymerization of olefins and photo-promoted cationic polymerization of epoxides. © 2012 by the authors.
Anselme K.,CNRS Mulhouse Institute of Materials Science |
Bigerelle M.,CNRS Roberval Laboratory (Mechanical Research Unit)
International Materials Reviews | Year: 2011
Many approaches are used to modify the surface topography of implant materials. Some produce unordered surfaces using, for example, classical implant surface treatments, whereas others produce ordered surfaces by micro- and nanopatterning techniques. Surface topographies can be characterised by several methods that can acquire two-dimensional profiles or three-dimensional measurements and calculate different roughness parameters. The importance of using systematically several roughness parameters for correlation with biological response, and of consider these parameters at different scales will be demonstrated. Furthermore, it will be described, from a general point of view, how cells are able to identify and respond to surface topography. The role of membrane receptors, cytoskeleton, filopods and intracellular signal transduction in the response to topography will be considered and discussed. A critical review of more than 300 papers provides the basis for illustrating how mammalian cells respond to surface topography and how their rugophilia, the increased cell response to rougher surfaces, is a function of cell phenotype. For the first time, the rugophilia of cells from different tissue origins is compared in a synthetic table. © 2011 Institute of Materials, Minerals and Mining and ASM International.
Lebeau B.,CNRS Mulhouse Institute of Materials Science |
Innocenzi P.,Consortium for Science and Technology of Materials
Chemical Society Reviews | Year: 2011
The interest in organic-inorganic hybrids as materials for optics and photonics started more than 25 years ago and since then has known a continuous and strong growth. The high versatility of sol-gel processing offers a wide range of possibilities to design tailor-made materials in terms of structure, texture, functionality, properties and shape modelling. From the first hybrid material with optical functional properties that has been obtained by incorporation of an organic dye in a silica matrix, the research in the field has quickly evolved towards more sophisticated systems, such as multifunctional and/or multicomponent materials, nanoscale and self-assembled hybrids and devices for integrated optics. In the present critical review, we have focused our attention on three main research areas: passive and active optical hybrid sol-gel materials, and integrated optics. This is far from exhaustive but enough to give an overview of the huge potential of these materials in photonics and optics (254 references). © 2011 The Royal Society of Chemistry.
Anselme K.,CNRS Mulhouse Institute of Materials Science
Osteoporosis International | Year: 2011
In this paper, some examples from the literature or from my own experience will be given to illustrate the influence of surface topography and surface chemistry at the nano-and micro-scale on the cell and tissue response. © International Osteoporosis Foundation and National Osteoporosis Foundation 2011.
Ghimbeu C.M.,CNRS Mulhouse Institute of Materials Science
Nature Materials | Year: 2016
Despite kerogen’s importance as the organic backbone for hydrocarbon production from source rocks such as gas shale, the interplay between kerogen’s chemistry, morphology and mechanics remains unexplored. As the environmental impact of shale gas rises, identifying functional relations between its geochemical, transport, elastic and fracture properties from realistic molecular models of kerogens becomes all the more important. Here, by using a hybrid experimental–simulation method, we propose a panel of realistic molecular models of mature and immature kerogens that provide a detailed picture of kerogen’s nanostructure without considering the presence of clays and other minerals in shales. We probe the models’ strengths and limitations, and show that they predict essential features amenable to experimental validation, including pore distribution, vibrational density of states and stiffness. We also show that kerogen’s maturation, which manifests itself as an increase in the sp2/sp3 hybridization ratio, entails a crossover from plastic-to-brittle rupture mechanisms. © 2016 Nature Publishing Group