胺类添加物对离子表面活性剂胶束化的影响

用电导法系统地研究了在pH7.00±0.01离子强度为0.1mol/LKNO3的Tris缓冲溶液中,4种胺类添加物对阴、阳离子表面活性剂(十二烷基硫酸钠SDS和十六烷基三甲基溴化铵CTAB)临界胶束浓度的影响.实验结果表明:表面活性剂的临界胶束浓度(cmc)随胺类添加物浓度的增加而明显降低,且添加物在相同浓度时降低cmc的程度遵循如下的顺序:四乙烯五胺>三乙烯四胺>二乙烯三胺>乙二胺.

Effects of Amine Additives on Micellization of Ionic Surfactants

The authors described the effect of four types of amine (ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine) as polar additives on the critical micellar concentrations(cmc) of ionic surfactants(cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS)) in buffered solutions (I=0.1 mol KNO_(3), 0.01 mol Tris-TrisH~(+)) at pH 7.00 0.01 by electrical conductivity method. It was found that the critical micellar concentrations(cmc) of these surfactants all decreased notably with the increase in concentrations of amine and the extent of effect followed the same sequence as: tetraethylenepentamine> triethylenetetramine > diethylenetriamine > ethylenediamine. Based on the results, several empirical formulae were obtained by the linear-fitting method, their general formula can be expressed as: lgcmc=A- BlgCi, where Ci is the concentration of amine, A and B are all empirical parameters (the correlation coefficients were all >0.98).