Temperature effects on surfactant aqueous two-phase systems

• Published in: Zhejiang da xue xue bao. Journal of Zhejiang University. Sciences edition. Li xue ban Vol. 40; no. 6; pp. 654 - 659
• Main Authors: He, Jia-Lei, Zhang, Shan-Shan, Wang, Yan-Yu, Lei, Qun-Fang, Fang, Wen-Jun
• Format: Journal Article
• Language: Chinese
• Published: Zhejiang University Press 01.11.2013
• Subjects: Absorption spectroscopy; Ammonium bromides; Cationic; Crystals; Phase inversion; Phase shift; Sodium; Surfactants; 双水相; 温度效应; 相倒置; 紫外-可见吸收; 表面活性剂
• ISSN: 1008-9497
• DOI: 10.3785/j.issn.1008-9497.2013.06.009

The cationic surfactants, N-dodecyl-N-(2-hydroxyethyl)-N, N-dimethyl ammonium bromide (C(12)HDAB) and N-dodecyl-N, N-2-dihydroxyethyl-N-methyl ammonium bromide (C(12)DHAB), have been synthesized by the reactions of N, N-dimethyl-N-hydroxyethylamine and N-methyl-N, N-2-dihydroxyethylamine with 1-bromododecane. They are mixed with sodium dodecyl sulfate (SDS) to form anionic/cationic surfactant aqueous two-phase systems with cationic surfactant in excess (ATPS-C). The temperature effects on the ATPS-C of C(12)HDAB/C(12)DHAB-SDS-NaBr systems has been investigated. It follows that the areas of the ATPS-C regions become a little wider and shift slightly to the cationic surfactant side as temperature increases in a certain tempature range. With temperature increasing, the mixed anionic/cationic surfactant system usually experiences white emulsion, two-phase system and ATPS disappearing processes. Especially, the phase inversion for specific ATPS-C can be observed by adjusting the temperature. The system that contai