哌啶季铵盐双子表面活性剂的合成及聚集行为

Synthesis and Aggregation Behavior of Gemini Surfactants with Piperidinium Structure

通过两步法合成了一系列基于哌啶的新型阳离子双子表面活性剂Fn(其中n代表疏水尾链所含碳原子个数,n=10,12,14,16),并通过表面张力法、电导法、稳态荧光法研究了他们在水溶液中的吸附和胶束化行为.研究发现随着疏水尾链增长,临界胶束浓度的值降低,最小单分子占有面积的值增大.热力学参数表明Fn系列双子表面活性剂体系的聚集是一个自发的过程,且随着疏水尾链增长,聚集趋势变强.摩尔电导率的研究表明在F14和F16两个体系中形成了预胶束的结构.动态光散射和透射电镜技术证实4种双子表面活性剂的水溶液中形成了曲率较小的囊泡结构.

A series of novel cationic Gemini surfactants Fn based on piperidine were synthesized in two steps （n is the carbon numbers of hydrophobic tails, n=10, 12, 14, 16）. Their adsorption and micellization in aqueous solutions were investigated by methods of surface tension, conductivity and steady state fluorescence. It was found that the values of low critical micelle concentration decrease and the values of minium surface area per molecule increase with the hydrophobic chain increasing. The thermodynamic parameters suggest that the aggregating of Fn series Gemini surfactants is a spontaneous process. And the tendency of aggregating becomes stronger with the increase of hydrophobic chain. The study of molar conductivity demonstrates that premicellar structures form in F14 and F,6 system, and small curvature radius vesicles form in the aqueous solutions of the four Gemini surfactants by dynamic light scattering and transmission electron microscopy.