摘要
采用表面张力法研究了9种阴-非离子型Gemini表面活性剂在水溶液中胶束化的热力学性质,并考察了温度与分子结构对胶束化的影响。实验结果表明,阴-非离子型Gemini表面活性剂在水溶液中胶束化是一个自发过程,主要来自熵驱动,温度升高不利于胶束化,且标准熵变对标准吉布斯自由能变的贡献有下降趋势,标准焓变对标准吉布斯自由能变的贡献有增大趋势;阴-非离子型Gemini表面活性剂在水溶液中胶束化存在焓熵补偿现象,焓熵补偿温度均在(307±2)K范围内,基本不随阴-非离子型Gemini表面活性剂的分子结构的改变而变化,随联接链增长或氧乙烯结构单元数目的增加,形成胶束的能力与稳定性均提高,随温度的升高,形成胶束的能力与稳定性均下降;临界胶束浓度的对数与联接链长度呈线性关系。
A series of anionic-nonionic Gemini surfactants were synthesized and the thermodynamics of their micellization in aqueous solution was investigated by the surface tension method. The influences of temperature and molecular structure on the micellization were discussed. The results show that the micellization is spontaneous and entropy-driving, and temperature rise is disadvantageous to the micellization. The contribution of the standard entropy change to change of the standard Gibbs free energy tends to decrease, and the contribution of the standard enthglpy change to change of the standard Gibbs free energy tends of increase. There is enthalpy-entropy compensation in the micellization and the compensation temperature is （307±2） K, which is independent of the molecule structures of the anionic-nonionic Gemini surfactants. The formation of the micelles and the stability of the micellization are enhanced when the spacer length or the ethylene oxide unit increase. There is a good linear relationship between the IgCMC（CMC： critical micelle concentration） and spacer length.
出处
《石油化工》
CAS
CSCD
北大核心
2013年第1期39-46,共8页
Petrochemical Technology
基金
"十二五"国家科技重大专项(2011ZX05011)
国家自然科学基金项目(50174033)
