Zeng X, Osseo-Asare K
Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
J Colloid Interface Sci. 2004 Apr 15;272(2):298-307. doi: 10.1016/j.jcis.2003.11.009.
The partitioning behavior of silica particles was investigated in the Triton X-100/dextran/water system. It was found that both electrostatic effects and interactions between phase-component species and the solid surface played important roles in determining the distribution of solids. Silica partition was highly pH-dependent, which was interpreted in terms of the pH dependence of the Triton X-100/SiO(2) interaction and the weak acidity of dextran. The presence of sodium dodecyl sulfate (SDS) moved the particles from the top surfactant-rich phase to the interface and the bottom phase, while dodecyltrimethylammonium bromide (DTAB) had the opposite effect. These trends are attributable to the electrostatic interaction between the charged mixed micelles in the top phase and the particles and to the fact that the ionic surfactants modified the adsorption density of the nonionic surfactant on silica.
研究了二氧化硅颗粒在Triton X-100/葡聚糖/水体系中的分配行为。结果发现，静电效应以及相组分物种与固体表面之间的相互作用在决定固体的分布方面都起着重要作用。二氧化硅的分配高度依赖于pH值，这可以从Triton X-100/二氧化硅相互作用对pH值的依赖性以及葡聚糖的弱酸性来解释。十二烷基硫酸钠（SDS）的存在使颗粒从富含表面活性剂的上相转移到界面和下相，而十二烷基三甲基溴化铵（DTAB）则有相反的效果。这些趋势归因于上相中带电混合胶束与颗粒之间的静电相互作用，以及离子表面活性剂改变了非离子表面活性剂在二氧化硅上的吸附密度这一事实。
