title: Phase behaviour and temperature-responsive properties of a gemini surfactant/Brij-30/water system.
abstract: The phase behaviour of a ternary system composed of cationic gemini surfactant 2-hydroxypropyl-1,3-bis(myristyldimethylammonium chloride) (14-3(OH)-14(2Cl)), nonionic surfactant polyoxyethylene laurel ether (C12H25(OCH2CH2)10OH, Brij-30) and H2O was studied and its phase diagram was determined. In several different phase regions identified in the phase diagram, the viscoelastic worm-like micellar solution region was investigated. The focus of the investigation was the increase in the viscosity of the micellar solution with the temperature and the Brij-30 content, as suggested by a partial region of the triangular phase diagram. With an increase in the Brij-30 content or temperature, one-dimensional micellar growth occurred, and a maximum appeared in the zero-shear viscosity, η0, versus Brij-30 content or temperature curves; this was true for mixed solutions containing 14-3(OH)-14(2Cl) and Brij-30 in different mass ratios (WBrij-30/W14-3(OH)-14(2Cl)). After the maximum point, the decrease in viscosity is the result of the micellar shortening in the size with Brij-30 content and of the micellar branching in the network structure with temperature. This rheological analysis was performed to investigate the structural changes in different solutions as well as the effects of various factors on micellar growth. Various techniques were used to study the phase-transition processes occurring in this system, including cryogenic transmission electron microscopy, small-angle X-ray scattering measurements, and differential scanning calorimetry. The transition mechanisms of the aggregates were analysed on the basis of the obtained results.
authors.affiliation: Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong 252059, P. R. China. weixilian@126.com weixilian@lcu.edu.cn.
authors.forename: Chuanhong
authors.identifier: http://orcid.org/0000-0002-5498-0011
authors.initials: C
authors.lastname: Han
authors.affiliation: Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong 252059, P. R. China. weixilian@126.com weixilian@lcu.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong 252059, P. R. China. weixilian@126.com weixilian@lcu.edu.cn.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Chen
authors.affiliation: School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, P. R. China.
authors.forename: Meihuan
authors.initials: M
authors.lastname: Yao
authors.affiliation: Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong 252059, P. R. China. weixilian@126.com weixilian@lcu.edu.cn.
authors.forename: Yingtian
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong 252059, P. R. China. weixilian@126.com weixilian@lcu.edu.cn.
authors.forename: Qirui
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong 252059, P. R. China. weixilian@126.com weixilian@lcu.edu.cn.
authors.forename: Xilian
authors.initials: X
authors.lastname: Wei