Lithium solvation in a PMMA membrane plasticized by a lithium-conducting ionic liquid based on 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide

• Published in: Journal of Raman spectroscopy Vol. 39; no. 9; pp. 1189 - 1194
• Main Authors: Duluard, Sandrine, Grondin, Joseph, Bruneel, Jean-Luc, Campet, Guy, Delville, Marie-Hélène, Lassègues, Jean-Claude
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01-09-2008; Wiley
• Subjects: Analytical chemistry; Anions; bis(trifluoromethanesulfonyl)imide; Chemical Sciences; Esters; Infrared; ionic liquid; Ionic liquids; Lithium; Material chemistry; Membranes; poly(methyl methacrylate) 1-butyl-3-methylimidazolium; Polymers; Polymethyl methacrylates; Raman spectroscopy; Spectra; Raman spectroscopy; Bis(trifluoromethanesulfonyl)imide; Poly(methyl methacrylate) 1-butyl-3-methylimidazolium; Ionic liquid
• ISSN: 0377-0486; 1097-4555
• DOI: 10.1002/jrs.1962

The Raman and Infrared (IR) spectra of poly(methyl methacrylate) (PMMA) membranes plasticized by ionic liquids of the (1 − x)[1‐butyl‐3‐methylimidazolium bis(trifluoromethanesulfonyl)imide (BMITFSI)],xLiTFSI type, where BMI+ is the 1‐butyl‐3‐methylimidazolium cation and TFSI− the bis(trifluoromethanesulfonyl)imide anion, are analyzed for a lithium bis(trifluoromethane sulfone)imide (LiTFSI) mole fraction x = 0.23 and PMMA contents from 0 to 50 wt%. The lithium is found to have an average coordination of about three CO groups and less than one TFSI− anion. It plays the role of a cross‐linker between the ester groups of PMMA and the nonvolatile ionic liquid. Addition of PMMA to the (1 − x)(BMITFSI),xLiTFSI ionic liquid lowers the conductivity but might improve the lithium transference number by transforming the [Li(TFSI)2]− anionic clusters present in the pure ionic liquid into a mixed coordination by ester groups and TFSI− anions. Copyright © 2008 John Wiley & Sons, Ltd.