Fragility of Ionic Liquids Measured by Flash Differential Scanning Calorimetry

摘要

Ionic liquids are a class of materials that possess attractive properties. They generally have low rates of crystallization and are often considered as good glass-forming materials. In this work, a series of imidazolium-based ionic liquids with varying functionalities from aliphatic to aromatic groups and a fixed anion are characterized using a commercial rapid scanning nanocalorimetry instrument, the Mettler Toledo Flash DSC. The limiting fictive temperature T_f' is measured on heating as a function of cooling rate. The dynamic fragility is obtained for the series of ionic liquids, and using this data along with a compilation of data from the literature reveals the relationship between molecular structure and fragility for ionic liquids.