Li X, Lin E, Zhao G, Xiao T
Department of Chemistry, Northwest Normal University, Lanzhou, People's Republic of China, 730070
J Colloid Interface Sci. 1996 Dec 1;184(1):20-30. doi: 10.1006/jcis.1996.0593.
The phase behavior and solubilization of multiphase microemulsions in mixed anionic-cationic surfactant systems were studied for fixed ratios of water-to-oil and surfactant-to-alcohol. In the mixed surfactants (sodium dodecyl sulfate + cetyltrimethylammonium bromide)/heptane/alcohol/water systems, microemulsion and birefringent phases are formed by adjusting the surfactant ratio epsilon and the cationic weight fraction delta. The bicontinuous (or w/o microemulsion) --> birefringent o/w microemulsion transition takes place and microemulsion domain enlarges with increasing epsilon. The optimum surfactant concentration gamma increases and the corresponding optimum delta decreases with increasing epsilon and both of them decrease with increasing the alcohol chain length from butanol to hexanol. The birefringent region shrinks rapidly with increasing alcohol and/or CTAB weight fractions in total surfactant concentration. Conductivity measurements have been performed in the single-phase region of the system containing mixed surfactants and alcohols at 25°C. The conductivity results indicate where a transition takes place and which of these different types of phase structures may be in the single-phase of the system containing anionic-cationic mixed surfactants.
在水与油以及表面活性剂与醇的比例固定的情况下，研究了混合阴离子 - 阳离子表面活性剂体系中多相微乳液的相行为和增溶作用。在混合表面活性剂（十二烷基硫酸钠 + 十六烷基三甲基溴化铵）/庚烷/醇/水体系中，通过调节表面活性剂比例ε和阳离子重量分数δ形成微乳液和双折射相。随着ε的增加，发生双连续（或油包水微乳液）→双折射水包油微乳液转变，且微乳液区域扩大。最佳表面活性剂浓度γ随着ε的增加而增加，相应的最佳δ随着ε的增加而减小，并且它们都随着醇链长度从丁醇增加到己醇而减小。随着醇和/或十六烷基三甲基溴化铵在总表面活性剂浓度中的重量分数增加，双折射区域迅速缩小。在25℃下对含有混合表面活性剂和醇的体系的单相区域进行了电导率测量。电导率结果表明在含有阴离子 - 阳离子混合表面活性剂的体系的单相中发生转变的位置以及可能存在的这些不同类型的相结构中的哪一种。
