期刊
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
卷 508, 期 -, 页码 79-84出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.colsurfa.2016.08.020
关键词
Gemini surfactant; Cleavable spacer; Cationic surfactant; Emulsion stability; Phase separation; Centrifugation
In this study, a cationic gemini surfactant with cleavable spacer and two monomeric single chain counterparts were synthesized and used. The critical micelle concentration (CMC) was measured by tensiometry for these surfactants. The emulsion stability of (Toluene 30:70 Water) emulsions in the presence of these surfactants and at various concentrations was determined by two dispersion testers (i.e. Turbiscan (R) under gravity force and Lumisizer (R) analytical centrifuge). The surfactant critical concentration for the emulsion stability was found to be at 2 x CMC. The emulsion stability in the presence of these surfactants followed the same trend and remained almost constant at surfactant concentration (2-6 x CMC). The gemini surfactant with lower CMC value is far better an emulsion stabilizer on concentration basis than the monomeric surfactants. The phase separation velocities of the emulsions as a function of the relative centrifugal force were fitted with linear and power correlations. The results showed that the estimated separation velocities at earth's gravity (1 x g) are larger than the measured values by Turbiscan for all of the surfactants. While the accelerated phase separation by Lumisizer is a fast and easy method for testing the emulsion stability and comparing the predicted shelf lives, the extrapolation and estimation of the real emulsion stability should be considered cautiously. (C) 2016 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据