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Synthesis and Properties of Room‐Temperature Choline Carboxylate Zwitterionic Ionic Liquids as Potential Electrolytes
Author(s) -
Rocha Ângelo,
Carvalho Tânia,
Vidinha Pedro,
Lourenço Nuno M. T.
Publication year - 2012
Publication title -
chempluschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.801
H-Index - 61
ISSN - 2192-6506
DOI - 10.1002/cplu.201200247
Subject(s) - ionic liquid , carboxylate , electrolyte , thermal stability , chemistry , ionic conductivity , imide , glass transition , dissociation (chemistry) , atmospheric temperature range , ionic bonding , inorganic chemistry , conductivity , choline , ion , lithium (medication) , polymer chemistry , organic chemistry , polymer , thermodynamics , medicine , biochemistry , physics , electrode , endocrinology , catalysis
Choline carboxylate zwitterions were prepared by two different synthetic routes through esterification of choline salts with a range of anhydrides. Their conjugation with lithium bis(trifluoromethylsulfonyl)imide resulted in the formation of stable room‐temperature ionic liquids. In view of their use as potential electrolytes the physicochemical characterization of these attractive ionic liquids was performed. These compounds presented a glass transition temperature between −43 and −34 °C, good thermal stability up to 224 °C, densities above 1.44 g cm −3 at 25 °C, and viscosities between 3.56 and 12.27 Pa s at 25 °C. In terms of conductivity the most promising ionic liquid showed an excellent conductivity between 8.66×10 −5 S cm −1 at 25 °C and 1.80×10 −3 S cm −1 at 90 °C. These zwitterionic ionic liquids maintained a liquid state, and no dissociation was observed even after six months of storage at room temperature.