N-烷基-N-(2-羟乙基)-N,N-二甲基溴化铵与十二烷基硫酸钠复配系统的双水相

Aqueous Two-phase Systems of N-Alkyl-N-(2-hydroxyethyl)-N,N-dimethylammonium Bromide and Sodium Dodecyl Sulfate Mixtures

合成了N-十二烷基-N-(2-羟乙基)-N,N-二甲基溴化铵、N-十四烷基-N-(2-羟乙基)-N,N-二甲基溴化铵和N-十六烷基-N-(2-羟乙基)-N,N-二甲基溴化铵等3个季铵盐阳离子表面活性剂.研究了它们以及N-十六烷基-N,N,N-三甲基溴化铵(CTAB)与阴离子表面活性剂十二烷基硫酸钠(SDS)复配系统在313.15K时的双水相行为.复配系统在两个非常狭窄的区域能形成双水相,两相区近似以等摩尔线为中心对称分布,随着阳离子表面活性剂碳链长度的增长,富含阳离子表面活性剂的双水相区向阴阳离子表面活性剂摩尔比减小的方向稍有移动.

Three cationic surfactants, N-dodecyl-N-（2-hydroxyethyl）-N,N-dimethylammonium bromide, N-tetradecyl-N-（2-hydroxyethyl）-N,N-dimethylammonium bromide and N-cetyl-N-（2-hydroxyethyl）-N,N-dimethylammonium bromide have been synthesized.The aqueous two-phase systems of surfactant mixtures from such N-alkyl-N-（2-hydroxyethyl）-N,N-dimethylammonium bromides or N-cetyl-N,N,N-trimethyl-ammonium bromide（CTAB） with sodium dodecyl sulfate（SDS） have been investigated at 313.15 K.The results indicate that two aqueous two-phase regions can be observed in these mixed cationic-anionic surfactant systems.The two regions are nearly symmetric to the equimolar line.With the increase of chain length in the cationic surfactants, the aqueous two-phase regions with abundant cationic surfactants shift slightly to the lower molar ratio of anionic surfactant versus cationic one.