摘要
利用电导法研究了离子液体表面活性剂溴代-1-十四烷基-3-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(ΔGm)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-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。
Micellar properties of ionic liquid surfactant, 1-tetradecyl-3-methylimidazolium bromide （C14 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 miceUization （AGmG ） 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.
出处
《石油化工高等学校学报》
CAS
2013年第2期12-16,共5页
Journal of Petrochemical Universities
基金
辽宁省科学技术厅项目资助(2009402004)
关键词
离子液体
胶团化
临界胶束浓度
乙二醇-水混合溶剂
热力学参数
Ionic liquid
Micellization
Critical micelle concentration
EG-water mixed solvent
Thermodynamic parameters
