; Chen, Xiao
; Wang, Xudong] Shandong Univ, Minist Educ, Key Lab Colloid & Interface Chem, Jinan 250100, Peoples R China
; [Li, Zhihong] Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
The phase behaviors of four phytosterol ethoxylates surfactants (BPS-n, n = 5, 10, 20, and 30) with different oxyethylene units in room temperature ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF(4)), have been studied. The polarized optical microscopy and small-angle X-ray scattering techniques are used to characterize the phase structures of these binary systems at 25 degrees C. The structure and ordering of the liquid crystalline (LC) phases in such BPS-n/[Bmim]BF(4) systems are found to be influenced by BPS-n concentration and the temperature. Due to the bulky and rigid cholesterol group, the phytosterol ethoxylates surfactants exhibit different properties and interaction mechanism from the conventional C(n)EO(m) type nonionic surfactant systems. The rheological measurements indicate a highly viscoelastic nature of these lyotropic LC phases and disclose a lamellar phase characteristic with a rather strong rigidity at high surfactant concentrations. The control experiment with Brij 97(polyoxyethylene (10) oleyl ether)/[Bmim]BF(4) system and the FTIR measurements help to recognize that the solvophobic interaction combining with the hydrogen bonding are the main driving forces for the LC phases formation. (C) 2011 Elsevier B.V. All rights reserved.
Yue, X,Chen, X,Wang, XD,et al. Lyotropic liquid crystalline phases formed by phyosterol ethoxylates in room-temperature ionic liquids[J]. COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS,2011,392(1):225-232.
Yue, X,Chen, X,Wang, XD,Li, ZH,&李志宏.(2011).Lyotropic liquid crystalline phases formed by phyosterol ethoxylates in room-temperature ionic liquids.COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS,392(1),225-232.
Yue, X,et al."Lyotropic liquid crystalline phases formed by phyosterol ethoxylates in room-temperature ionic liquids".COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS 392.1(2011):225-232.