Slow molecular mobility in the amorphous solid and the metastable liquid states of three 1-alkyl-3-methylimidazolium chlorides

摘要

The slow molecular mobility in three ionic liquids, 1-alkyl-3- methylimidazolium chlorides with alkyl tails C_4, C_6 and C_8, has been investigated by thermally stimulated depolarization currents (TSDC) and differential scanning calorimetry (DSC), in a temperature interval including the amorphous solid and the supercooled liquid state. A specific feature of these ionic liquids, compared with typical molecular liquids, is the existence of a slow relaxation close to the main relaxation but above T_g, which is cooperative and shows a high dielectric strength.