关键词: 离子液体, 甲醇, 局部组成模型, 溶液, 微观结构

Abstract: The 1H NMR of three ionic liquids-methanol (ILs-methanol) systems was measured over the whole range of mole fraction from 0 to 1. The three ILs-methanol systems were 1-ethyl-3-methylimidazolium tetrafluoroborate-methanol system，1-butyl-3-methylimidazolium tetrafluoroborate-methanol system and 1-hexyl-3-methylimidazolium tetrafluoroborate-methanol system. The local composition model was used to correlate 1H NMR chemical shifts values of ILs and methanol. The obtained local mole fraction was used to analyze the local structure of three ILs-methanol systems. The effect of alkyl chain length in cations was studied. The difference between local composition and macroscopic composition of the ionic liquids was very small in three ILs-methanol systems. Methanol molecules preferred to self-associate in the imidazolium-based ILs with a long alkyl chain.

Key words: ionic liquid, methanol, local composition model, solution, structure