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Le Cloirec P.,National Graduate School of Chemistry, Rennes
Chinese Journal of Chemical Engineering | Year: 2012

A general research program, focusing on activated carbon fiber cloths (ACFC) and felt for environmental protection was performed. The objectives were multiple: (i) a better understanding of the adsorption mechanisms of these kinds of materials; (ii) the specification and optimization of new processes using these adsorbents; (iii) the modeling of the adsorption of organic pollutants using both the usual and original approaches; (iv) applications of ACFC in industrial processes. The general question was: how can activated carbon fiber cloths and felts be used in air treatment processes for the protection of environment. In order to provide an answer, different approaches were adopted. The materials (ACFC) were characterized in terms of macro structure and internal porosity. Specific studies were performed to get the air flow pattern through the fabrics. Head loss data were generated and modeled as a function of air velocity. The performances of ACF to remove volatile organic compounds (VOCs) were approached with the adsorption isotherms and breakthrough curves in various operating conditions. Regeneration by Joule effect shows a homogenous heating of adsorber modules with rolled or pleated layers. Examples of industrial developments were presented showing an interesting technology for the removal of VOCs, such as dichloromethane, benzene, isopropyl alcohol and toluene, alone or in a complex mixture. © 2012 Chemical Industry and Engineering Society of China (CIESC) and Chemical Industry Press (CIP). Source

Kluciar M.,University of Warsaw | Grela K.,University of Warsaw | Mauduit M.,National Graduate School of Chemistry, Rennes
Dalton Transactions | Year: 2013

Two ruthenium-based pre-catalysts containing an ionic tag covalently connected to a N-heterocyclic carbene (NHC) ligand are reported. These novel complexes, bearing a polar benzimidazolium group, are air-stable and can be easily prepared from commercially available reagents. The quaternary benzimidazolium tag allows the efficient separation of ruthenium waste from the metathesis product after reaction. Application in several olefin metathesis transformations leads to desired products of high purity, which exhibit ruthenium contamination levels as low as 1 ppm after simple filtration through a pad of silica gel. © 2013 The Royal Society of Chemistry. Source

Giraudet S.,National Graduate School of Chemistry, Rennes | Giraudet S.,European University of Brittany | Zhu Z.,University of Queensland
Carbon | Year: 2011

Ordered mesoporous carbons were enriched with nitrogen, then loaded with nickel nanoparticles and the effects on hydrogen storage were investigated. Firstly, a comparative characterization was carried out using transmission electronic microscopy, X-ray diffraction, nitrogen adsorption isotherm and thermogravimetric analysis. It was shown that the nickel was interacting with the nitrogen functional groups on the surface of the carbon support and even led to the formation of particles of different sizes. Secondly, hydrogen storage was studied. Hydrogen adsorption by volumetric method at 77, 298 and 373 K and high pressures (3 MPa) exhibited two distinct behaviors. At 77 K, the textural properties are critical and the adsorption capacities decreased with the nickel loading. On the contrary, at ambient and higher temperatures, the contribution of nickel nanoparticles was positive and marked by increased amounts of hydrogen reversibly adsorbed. Furthermore, the electrosorption of hydrogen was examined. It consists of the electrolysis of water that causes the formation and the diffusion of hydrogen on the adsorbent surface. In that particular application, the combination of nickel doping and nitrogen enrichment was detrimental to the adsorption capacities. However, nickel doped on pure carbons enhanced the amount of hydrogen electrosorbed. © 2010 Elsevier Ltd. All rights reserved. Source

Loyer P.,University of Rennes 1 | Cammas-Marion S.,National Graduate School of Chemistry, Rennes
Journal of Drug Targeting | Year: 2014

The field of specific drug delivery is an expanding research domain. Besides the use of liposomes formed from various lipids, natural and synthetic polymers have been developed to prepare more efficient drug delivery systems either under macromolecular prodrugs or under particulate nanovectors. To ameliorate the biocompatibility of such nanocarriers, degradable natural or synthetic polymers have attracted the interest of many researchers. In this context, poly(malic acid) (PMLA) extracted from microorganisms or synthesized from malic or aspartic acid was used to prepare water-soluble drug carriers or nanoparticles. Within this review, both the preparation and the applications of PMLA derivatives are described emphasizing the in vitro and in vivo assays. The results obtained by several groups highlight the interest of such polyesters in the field of drug delivery. © 2014 Informa UK Ltd. Source

National Graduate School of Chemistry, Rennes and French National Center for Scientific Research | Date: 2013-04-19

A process for enzymatically converting a furanoside substrate in a product of interest, includes contacting the substrate with an enzyme in presence of an alcohol acceptor, wherein the enzyme is preferably Araf51, and wherein the product is preferably an alkyl furanoside. The mutant Araf51 enzyme showing improved transglycosylation activity in comparison with the native wild-type (wt) Araf51 enzyme, and a method for screening the mutants are also described.

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