Encyclopedia of Ionic Liquids : Conversion of Chitin in Ionic Liquids

International audienc

Encyclopedia of Ionic Liquids : Conversion of Chitin in Ionic Liquids

International audienc

New iodide-based amino acid molecules for more sustainable electrolytes in dye-sensitized solar cells

International audienceThe electrolyte is the second key component governing at once the power conversion performances and the stability of dye-sensitized solar cells. Towards the integration of more sustainable materials, we have focused on the replacement of the major constituent of the electrolyte, namely the 1,3-di-alkyl imidazolium iodide. We synthesized two new iodide molecules derived from the natural amino acid L-proline: (S)-2-(methoxycarbonyl)-1,1-dimethylpyrrolidinium iodide (PMeI) and (S)-2-(ethoxycarbonyl)-1,1-ethylpyrrolidinium iodide (PEtI). In combination with the C106 polypyridyl ruthenium(+II) sensitizer, power conversion efficiencies of 7.1% for PMeI and 6.5% for PEtI were obtained under standard Air Mass 1.5G conditions in conjunction with the low-volatile 3-methoxypropionitrile-based solvent. The relationships between these iodide molecules with the power conversion efficiencies and the interfacial charge transfer processes are herein discussed, and the new iodide molecules are systematically compared to the best standard 1,3-di-methylimidazolium iodide

Towards Renewable Iodide Sources for Electrolytes in Dye-Sensitized Solar Cells

A novel family of iodide salts and ionic liquids based on different carbohydrate core units is herein described for application in dye-sensitized solar cell (DSC). The influence of the molecular skeleton and the cationic structure on the electrolyte properties, device performance and on interfacial charge transfer has been investigated. In combination with the C106 polypyridyl ruthenium sensitizer, power conversion efficiencies lying between 5.0% and 7.3% under standard Air Mass (A.M.) 1.5G conditions were obtained in association with a low volatile methoxypropionitrile (MPN)-based electrolyte

Synthesis of High Molecular Weight Chitosan from Chitin by Mechanochemistry and Aging

Chitosan can be obtained from the deacetylation of chitin. This process is however difficult and usually accompanied by depolymerization, affording low molecular weight chitosan. We report a novel path, relying on a combination of mechanochemitry and aging, to afford high molecular weight chitosan with minimal use of energy and solvent. This method is versatile and applicable to a number of chitin sources, including crude crustaceans and insect shells, yielding deacetylation up to 98% and remarkably high molecular weights. Chitin deacetylation was measured by magic angle spinning nuclear magnetic resonance and molecular weight by viscometry. This process affords chitosan in a safer fashion and with less materials and energy usage than the classic hydrothermal one

Fundamental insight into the interaction between a lithium salt and an inorganic filler for ion mobility using a synergic theoretical-experimental approach

International audienc

Syntheses and characterisation of hydrophobic ionic liquids containing trialkyl(2-ethoxy-2-oxoethyl)ammonium or N-(1-methylpyrrolidyl-2-ethoxy-2-oxoethyl)ammonium cations.

International audienceA series of salts based on ethyl ester betaine derivatives [trialkyl(2-ethoxy-2-oxoethyl)ammonium or N-(1-methylpyrrolidyl-2-ethoxy-2-oxoethyl)ammonium cations] with alkyl chains [ethyl, n-propyl and n-butyl] have been synthesized. These cations generate hydrophobic ionic liquids with bis(trifluoromethylsulfonyl)imide, tetrafluoroborate or dicyanamide anions. The influence of the alkyl chain length and the chemical nature of the counteranion on physicochemical properties such as density, melting point, glass transition and decomposition temperatures, viscosity, and electrochemical window have been investigated