多季铵盐表面活性剂的表面性能及胶束化热力学研究

Study on Surface Properties and Micellization Thermodynamics of Multi-Quaternary Ammonium Surfactant

以二乙胺盐酸盐、环氧氯丙烷及十二烷基二甲基叔胺为原料合成了多季铵盐表面活性剂CD3N-12,并对其结构进行了表征,采用滴体积法测定其表面性能,采用电导率法探讨其胶束化热力学过程。结果表明,CD3N-12的临界胶束浓度为1.00×10-3 mol·L-1,表面张力γCMC为36.34mN·m-1;随着无机盐NaCl、CaCl2的加入,反离子压缩了CD3N-12的双电层,CD3N-12水溶液的表面活性升高;随着温度的升高,CD3N-12的电导率升高,反离子结合度降低,其胶束化过程由熵驱动逐渐向焓驱动转变。

Using diethylamine hydrochloride,epichlorohydrin and dodecyl dimethylamine as raw materials,a multi-quaternary ammonium surfactant CD3N-12 was synthesized.The chemical structure of CD3N-12 was characterized.The surface property of CD3N-12 was measured by drop volume method,and the micellization thermodynamic process was investigated by conductivity method.Results showed that,the critical micelle concentration of CD3N-12 was 1.00×10-3 mol·L-1,the surface tension was 36.34 mN·m-1.With addition of NaCl,CaCl2 into CD3N-12 aqueous solution,the surface activity increased with Cl-compressing micelle electric double layer.Moreover,with the increasing of temperature,the conductivity of CD3N-12 was increased,while the binding force with the counter ion was decreased,and its process of micellization driven by the entropy was gradually transformed into enthalpy.