季铵盐双子表面活性剂的合成和表面活性

以吗啉和溴代烷为原料,合成了两种季铵盐双子表面活性剂(m-6-m,m=10,12),并用IR和1HNMR表征了其结构。测得28℃时,12-6-12和10-6-10的表面张力(γCMC)分别为26.45 mN/m和25.55 mN/m;临界胶束浓度(CMC)分别为1.0 mmol/L和3.1 mmol/L;pC20值分别为3.48和3.03;比表面过剩(Γmax)分别为2.72×10-6mol/m2和2.80×10-6mol/m2;分子最小截面积(Amin)分别为0.611 nm2和0.593 nm2。结果表明,该季铵盐双子表面活性剂与相同离子头基及烷基链的单季铵盐表面活性剂相比,CMC低一个数量级,γCMC相差不大。

Synthesis and Surface Activity of Cationic Gemini Surfactants

Two types of cationic gemini surfactants(m-6-m,m is 10,12) were synthesized with morpholine and alkyl bromide.The chemical structure of the purified products were confirmed using IR and 1HNMR.Surface tensions(γCMC) of 12-6-12 and 10-6-10 were measured at 28 ℃ and are respectively 26.45 mN/m and 25.55 mN/m;the critical micelle concentrations(CMC) are 1.0 mmol/L and 3.1 mmol/L;pC20 are 3.48 and 3.03;excess adsorption amounts(Γmax) are 2.72×10-6 mol/m2 and 2.80×10-6 mol/m2;and the saturation adsorption areas per molecule(Amin) are 0.611 nm2 and 0.593 nm2.The result shows that the surface tension of the gemini surfactants are similar as their corresponding "monomer",but their CMC are only one tenth of their "monomer".