Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia.
J Phys Chem B. 2012 Apr 19;116(15):4634-45. doi: 10.1021/jp212263b. Epub 2012 Apr 5.
Mixtures of polyelectrolytes and oppositely charged surfactants show very rich phase behavior that is influenced by surfactant-ion and polyion properties and by water content. A general feature is associative phase separation as a result of strong electrostatic interactions, whereas the effect of eventual more specific interactions (e.g., hydrophobic) has not been thoroughly investigated. In this paper, we report a detailed study on phase behavior and structures in poly(styrenesulfonate anion) (PSS(-))-cetyltrimethylammonium cation (CTA(+))-water mixtures that are characterized by a hydrophobic interaction between the styrene groups of PSS(-) and the micelle interior. Structures of various phases were determined by small-angle X-ray scattering, and results indicated the presence of a disordered micellar and an ordered hexagonal phase; no cubic phase was found. The general conclusion is that the highlighted hydrophobic interaction promotes dissolution of CTAPSS when the polyion salt is added and provides further stabilization of the dense phase when the surfactant salt is added.
聚电解质和带相反电荷的表面活性剂的混合物表现出非常丰富的相行为，受表面活性剂离子和聚离子特性以及含水量的影响。一个普遍的特征是由于强静电相互作用而发生缔合相分离，而最终更具体相互作用（例如疏水性）的影响尚未得到彻底研究。在本文中，我们报告了关于聚（苯乙烯磺酸盐阴离子）（PSS（-））-十六烷基三甲基铵阳离子（CTA（+））-水混合物的相行为和结构的详细研究，该混合物的特点是苯乙烯基团之间存在疏水相互作用PSS（-）和胶束内部。通过小角 X 射线散射确定了各种相的结构，结果表明存在无序胶束和有序六方相；未发现立方相。总的结论是，当加入聚离子盐时，突出的疏水相互作用促进了 CTAPSS 的溶解，而当加入表面活性剂盐时，提供了更密集相的进一步稳定。
