Abstract: The phase diagrams of lyotropic liquid crystal and the structure of lamellar liquid crystal were studied in ionic surfactant (sodium dodecyl surface, cetyl-trimethylammonium bromide) and nonionic surfactant (polyoxyethylene oleyl ether, polyoxyethylene nonylphenol) mixture systems. The nonionic surfactant with smaller polar group mixed with ionic surfactant tend to form lamellar liquid crystal, in which the phase behavior of the nonionic surfactant is similar to the fatty alcohol mixed with ionic surfactant. One with bigger polar group mixed with ionic surfactant tend to form hexagonal liquid crystal. The area of liquid crystal phase on phase diagram in anonic-nonionic mixed surfactants system is bigger than that in cationic-nonionic mixed surfactants system. The interaction between two kinds of surfactant molecules in the former is stronger than that in the latter. The thickness of amphiphile bilayer and average molecular area of lamellar liquid crystal were determined.

Key words: mixed surfactants, lyotropic liquid crystal

摘要： 对离子型表面活性剂十二烷基硫酸钠、十六烷基三甲基溴化铵与非离子表面活性剂聚氧乙烯油醇醚、烷基酚聚氧乙烯醚混合体系溶致液晶的相图及层状液晶的结构进行了研究。结果表明，当非离子表面活性剂中极性基较小时，其相行为类似于脂肪醇，易和离子型表面活性剂共同形成层状液晶。当非离子型表面活性剂极性基较大时，与离子型表面活性剂易形成六角液晶。在混合体系中阴离子表面活性剂比阳离子表面活性剂与聚氧乙烯型非离子表面活性剂的相互作用更强一些，表现为相图中形成的液晶区域较大。当离子型表面活性剂确定时，与脂肪醇聚氧乙烯醚复配比与烷基酚聚氧乙烯醚复配可形成液晶的范围更宽。

关键词: 溶致液晶, 混合表面活性剂