表面活性剂胶束化物理化学性质研究

Study on the Physical and Chemical Properties of Surfactant Micellization

通过电导法考查温度和盐浓度对十二烷基硫酸钠(SDS)临界胶束浓度(CMC)的影响,研究表面活性剂形成胶束过程的物理化学性质。根据拟相分离模型求得胶束化热力学函数,并讨论体系电导活化能随温度和SDS浓度变化关系。结果表明:SDS的CMC随温度升高而增加,随氯化钠浓度增大而减小。在热力学上SDS在水溶液中形成胶束是一个自发、放热、熵增的过程;在动力学上,SDS溶液电导率与温度关系符合Arrhenius公式,通过电导活化能信息可揭示离子型表面活性剂形成胶束的机理特征。

In this paper, the physical and chemical properties of micelle formation process of surfactants were studied by studying the influence of temperature and salt concentration on the critical micelle concentration(CMC) of sodium dodecyl sulfate(SDS) using conductivity method. The thermodynamic parameters of micelle formation were obtained according to the pseudo-phase separation model, and the conductance activation energy of the system dependence of temperature and SDS concentration was discussed. The results showed that CMC of SDS was increased with the increasing of temperature, and decreased with the increasing of sodium chloride concentration, suggesting a spontaneous, exothermic and entropy-increasing process in the micelle formation of SDS in aqueous solution;in kinetics, the relationship between the conductivity of the SDS solution and the temperature conforms to the Arrhenius formula, the activation energy information can reveal the mechanism of ionic surfactants forming micelles.