两性孪联表面活性剂的合成及其协同效应

Synthesis and Synergism of Zwitterionic Gemini Surfactant

通过月桂醇与2-氯-2-氧-1,3,2-二氧磷杂环戊烷低温酯化反应及与N,N-二甲基十二胺在65℃下亲核溶剂中开环反应合成了两性孪联表面活性剂(C12H25OPO-(O)O(CH2)2(CH3)2N+C12H25,C12-C12),其临界胶束浓度为0.009 2 mmol/L,最低表面张力为25.61 mN/m。采用界面张力法考察了两性表面活性剂C12-C12在癸烷中与十二烷基硫酸钠(SDS)的协同作用。不加电解质时,二者混合胶束能产生协同作用,但在降低界面张力上不具备协同作用;在质量分数为7%的NaCl溶液体系中,电解质降低了SDS/癸烷的界面张力,促进了SDS向胶束中转移,复配体系C12-C12/SDS/癸烷/NaCl具有降低界面张力效率、形成胶束能力的协同作用。

A novel zwitterionic gemini surfactant（C12H25OPO^-（O）O（CH2）2（CH3）2N^＋C12H25,C12-C12） was synthesized by the reaction of dodecyl alcohol with 2 - chloro 1,3,2 - dioxaphospholane 2 - oxide to yield an intermediate, which was subsequently ring- opened by an dodecyldimethylamine at 65）℃. The critical micelle concentration （emc） of C12 - C12 is 0. 009 2 mmol/L and the lowest surface tension is 25.61 mN/m. Synergisms of zwitterionic suffactant between the mixed surfactant system of SDS/C12 -C12 were investigated by interracial tension method. The result shows that there is synergism in the mixed micellation, but no interaction of decreasing inteffacial tension without NaCI. However, the mixed system has strong synergism in interfacial tension reduction efficiency and mixed micelle formation with addition of NaCl with 7% mass fraction, which reduce interfacial tension between SDS and decane and promote transporting of SDS molecular from solution to micellation.