二酯基连接链乙基头基季铵盐Gemini表面活性剂的合成及性质

Synthesis and Properties of Ammonium Salt Gemini Surfactants with Diethylammonium Headgroups and Diester Spacer

以长链溴代烷、二乙胺、氯乙酰氯和乙二醇为原料合成了5种新型二酯基连接链乙基头基季铵盐双子表面活性剂Gemini C10,Gemini C12,Gemini C14,Gemini C16,Gemini C18(尾链碳原子数依次为10,12,14,16,18),并研究了它们的表面性能和聚集体形态.结果显示,Gemini C10的临界胶束浓度(cmc)在20～40℃间随着温度升高而减小,而其他4种Gemini表面活性剂的cmc却随温度升高而增大;25℃时Gemini C10～C18在cmc时的表面张力随疏水链长度的增加呈降低趋势;Gemini产物在较高浓度下有囊泡聚集体形成,尺寸为40～200nm.

A series of ammonium salt Gemini surfactants（Gemini C10,Gemini C12,Gemini C14,Gemini C16,Gemini C18 whose hydrophobic chain numbers are 10,12,14,16,18）with diethylammonium headgroups and diester spacer were synthesized by using bromoalkane,diethylamine,chloroacetyl chloride and ethanediol.The surface activities and aggregate morphology were studied.When the temperature went up,the critical micelle concentration（cmc） of Gemini C10 decreased,but the cmc of the rest four Gemini surfactants increased.The surface tension of the five Gemini surfactants over 25 ℃ reveals that the cmc of those Gemini surfactants will decrease as the hydrophobic chain length increases.Vesicle whose size distribution is approximately forty nanometer to two hundred nanometer formed above their cmc in this series of compounds.