Abstract: Micellar properties of ionic liquid surfactant, 1tetradecyl3methylimidazolium bromide (C14mimBr) were investigated by means of electrical conductometry with emphasis on the influence of cosolventwater content and temperature. The critical micelle concentration (CMC) and the degree of counterion association (g) were calculated from the electrical data. The thermodynamic parameters applied an equilibrium model for micelle formation were obtained. It turned out that the standard Gibbs energies of micellization (ΔGm) was always negative indicating the spontaneity of micelle formation, but it is roughly independent of temperature. In EGpoor mixtures, the micelle formation is affected by entropyenthalpy compensation, whereas it is driven by enthalpy in EGrich mixtures.

Key words: Ionic liquid,    ,  Micellization,    , Critical micelle concentration,    ,  EGwater mixed solvent,   , Thermodynamic parameters

摘要： 暋利用电导法研究了离子液体表面活性剂溴代灢1灢十四烷基灢3灢甲基咪唑在混合溶剂以及不同温度下的胶团化行为。通过电导率数据计算了临界胶束浓度(CMC)和反离子缔合度(g)。应用相平衡模型估算了表面活性剂胶团形成的热力学参数。标准摩尔吉布斯自由能(殼G熯m )总是负值,表明了胶团化行为的自发性,而且与温度无关。当乙二醇(EG)体积分数在10%、15%的时候,胶团形成是焓灢熵补偿效应,相反在乙二醇体积分数20%的时候胶团化行为是焓驱动的。

关键词: 离子液体 , 胶团化 , 临界胶束浓度 , 乙二醇灢水混合溶剂 , 热力学参数