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1.
My-Loan-Phung Le Fannie Alloin Pierre Strobel Jean-Claude Lepr��tre Laure Cointeaux Carlos P��rez del Valle 《Ionics》2011,18(9):817-827
Ionic liquids, ILs, based on fluorinated pyrrolidinium and piperidinium ammonium cations and imide anion were prepared and characterized. The physicochemical and electrochemical properties of these ILs including melting point, glass transition and degradation temperatures, viscosity, ionic conductivity, and electrochemical stability were determined and compared to alkyl pyrrolidinium and piperidinium ILs. The incorporation of a CF3 group instead of a CH3 induces an increase of the IL viscosity, thus a conductivity decrease. However, good ionic conductivity is obtained with fluorinated pyrrolidinium IL. Cyclic amine ILs with propyl alkyl chain or fluorinated ammonium exhibit very high electrochemical stability toward oxidation. The effect of the addition of LiTFSI on the IL properties was studied with the same methodology. 相似文献
2.
R. Arvai F. Toulgoat M. Médebielle B. Langlois F. Alloin J.Y. Sanchez 《Journal of fluorine chemistry》2008,129(10):1029-1035
Several aryl-containing ammonium sulfonates have been prepared either by cationic metathesis from the corresponding lithium sulfonates or from the corresponding sulfonic acids. The latter have been obtained by elution of an Amberlite resin with alcoholic solutions of the lithium sulfonates. These ammonium sulfonates exhibit interesting conductivities and thermal properties which allow them to be promising candidates as electrolytes for electricity storage. 相似文献
3.
Nguyen Quang A. Tucker Melvin P. Keller Fred A. Eddy Fannie P. 《Applied biochemistry and biotechnology》2000,84(1-9):561-576
Whole treechips obtained from softwood forest thinnings were pretreated via single-and two-stage dilute-sulfuric acid pretreatment.
Whole-tree chips were impregnated with dilute sulfuric acid and steam treated in a 4-L steam explosion reactor. In single-stage
pretreatment, wood chips were treated using a wide range of severity. In two-stage pretreatment, the first stage was carried
out at low severity tomaximize hemicellulose recovery. Solubilized sugars were recovered from the first-stage prehydrolysate
by washing with water. In the second stage, water-insoluble solids from first-stage prehydrolysate were impregnated with dilute
sulfuric acid, then steam treated at more severe conditions to hydrolyze a portion of the remaining cellulose to glucose and
to improve the enzyme digestibility. The total sugar yields obtained after enzymatic hydrolysis of two-stage dilute acid-pretreated
samples were compared with sugar yields from single-stage pretreatment. The overall sugar yield from two-stage dilute-acid
pretreatment was approx 10% higher, and the net enzyme requirement was reduced by about 50%. Simultaneous saccharification
and fermentation using an adapted Saccharomyces cerevisiae yeast strain further improved cellulose conversion yield and lowered the enzyme requirement. 相似文献
4.
Tucker Melvin P. Mitri Ragheed K. Eddy Fannie P. Nguyen Q. A. Gedvilas Lynn M. Webb John D. 《Applied biochemistry and biotechnology》2000,84(1-9):39-50
The process of converting renewable lignocellulosic biomass to ethanol requires a number of steps, and pretreatment is one
of the most important. Pretreatment usually in volves a hydrolysis of the easily hydrolyzed hemicellulosic component of biomass
using some form of thermal/chemical/mechanical action that results in a product that can be further hydrolyzed by cellulase
enzymes (the cellulosic portion). The sugars produced can then befermented to ethanol by fermentative microorganisms. If the
pretreatment step is not severe enough, the resultant residue is not as easily hydrolyzed by the cellulase enzyme. More severe
pretreatment conditions result in the production of degradation products that are toxic to the fermentative microorgan ism.
In this article, wereport the quantitative analysis of glucose, mannose, xylose, and acetic acid using Fourier transform infrared
(FTIR) spectroscopy on liquors from dilute-acid-pretreated softwood and hard wood slurries. Comparison of FTIR and high-performance
liquid chromatography quantitative analyses of these liquorsare reported. Recent developments in infrared probe technology
has enabled the rapid quantification of these sugars by FTIR spectroscopy in the batch reactor during optimization of the
pretreatment conditions, or interfaced to the computer controlling a continuous reactor for on-line monitoring and control. 相似文献
5.
Some block copolymers based on polymethacrylonitrile (PMAN) and polyethers or polyacetals were synthesized in an anionic way. To appreciate the salt/polymer interactions, polymer electrolytes were prepared by the dissolution of lithium imide or lithium perchlorate in PMAN homopolymer and copolymers. The investigation of the triblock copolymer complexes allowed the solvating competition between nitrile‐ and ether‐ or acetal‐functional groups to be highlighted. The polydioxolane solvating ability was equivalent to that of PMAN but lower than that of polyoxyethylene or polyoxypropylene. Moreover, we were interested in the salt effect as block compatibilization was concerned. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3665–3673, 2005 相似文献
6.
J. Saunier F. Alloin J. Y. Sanchez B. Barrire 《Journal of Polymer Science.Polymer Physics》2004,42(3):544-552
Some microporous poly(vinylidene fluoride) (PVdF) separators for lithium‐ion batteries, used in liquid organic electrolytes based on a mixture of carbonate solvents and lithium salt LiPF6, were characterized by the study of the swelling phenomena on dense PVdF membranes. Various aspects of the kinetics of the carbonate solvents and the solvent mixture sorption in dense PVdF slabs were studied at different temperatures. Non‐Fickian behavior, characterized by S‐shaped sorption curves, was highlighted, and a salt effect, which resulted in two‐stage sorption, was studied. Diffusion coefficients and activation energies were calculated for the Fickian portions of the sorption curves, that is, at short times and low swelling ratios. A strong influence of the different interaction parameters was shown for the swelling kinetics. This study proved that the swelling of microporous PVdF membranes could be considered instantaneous. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 544–552, 2004 相似文献
7.
J. Saunier F. Alloin J. Y. Sanchez L. Maniguet 《Journal of Polymer Science.Polymer Physics》2004,42(12):2308-2317
Microporous poly(vinylidene fluoride) (PVdF) separators for lithium-ion batteries, used in liquid organic electrolytes, have been characterized with respect to the swelling phenomena on dense PVdF membranes (obtained through hot pressing). In the first and second parts of this study, we have described the swelling equilibria and swelling kinetics of dense PVdF. Here the thermal properties of PVdF gels and their irreversible modifications induced by swelling are characterized. Particular attention is paid to crystallinity modifications, polymer plasticization, and membrane degradation. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2308–2317, 2004 相似文献
8.
Jean-Yves Sanchez Fannie Alloin Cristina Iojoiu 《Journal of fluorine chemistry》2006,127(11):1471-1478
This contribution has been partly adapted from a special lecture intended to commemorate the Nobel prize, awarded one century ago, to Henri Moissan. It, is focused on fluorinated and perfluorinated molecules and macromolecules used in electrochemical energy sources, i.e. storage and conversion of energy. The latter, which figure indisputably among New Energy Technologies, include lithium batteries and fuel cells based on polymeric membranes both of which have tremendous development potential in terms of performances, safety and cost reductions. The advantages inherent in fluorine, in particular its electron-withdrawing effect and the oxidation stability that it provides to the carbon-fluorine bond, make it an asset in the search for new organic molecular and macromolecular anions with extensive delocalization of the negative charge, usable both in lithium batteries and fuel cells. As for fluorinated and perfluorinated macromolecule backbones, they are currently the reference material in fuel cell ionomeric membranes but some of them are also good candidates for use in lithium-ion batteries. This paper, far from being exhaustive, also emphasizes the economic aspects that influence material selection and also govern the future of basic research. 相似文献
9.
10.
The mobilities of lithium, PF6- and solvents in the electrolyte LiPF6-(ethylene carbonate-dimethyl carbonate-diethyl carbonate) were measured using the pulsed gradient spin-echo NMR. They were compared to those of the same electrolyte filling a macroporous poly(vinylidene fluoride) membrane. The conductivity decrease resulting in the incorporation of this macroporous membrane and the cationic transport number were analyzed in terms of (i) solvent/polymer and solvent/salt interactions, (ii) ionic dissociation, and (iii) tortuosity. 相似文献