title: Structural Transition of Cinnamate-Based Light-Responsive Ionic Liquids in Aqueous Solutions and Their Light-Tunable Rheological Properties.
abstract: Light-responsive wormlike micelles have important applications in fields such as microfluids, photoswichable fluids, and rheology control. However, single-component light-responsive wormlike micelles formed only from a single tail surfactant have not been reported in literature. In this work, self-assembly behavior of 1-alkyl-3-methylimidazolium trans-ortho-methoxycinnamate [Cnmim][OMCA] (n = 8, 10, 12, 14, 16) ionic liquids in aqueous solutions is studied by UV-vis spectroscopy, viscosity, rheology, conductivity, and cryo-TEM measurements. It is found for the first time that, among the single tail ionic liquid surfactants studied, [C16mim][OMCA] can form wormlike micelles in aqueous solutions without any additives and light irradiation. Then these wormlike micelles are able to transform into cylindrical micelles under UV light irradiation, resulting in significantly tunable rheological properties of the solutions. The photoisomerization of anion of [C16mim][OMCA] from trans- to cis-isomer as well as the relative hydrophilicity and structural feature of the cis-isomer are suggested to be responsible for such transition.
authors.affiliation: Henan Key Laboratory of Green Chemical Media and Reactions, School of Chemistry and Chemical Engineering, Henan Normal University , Xinxiang, Henan 453007, P. R. China.|School of Basic Medicine, Xinxiang Medical University , Xinxiang, Henan 453007, P. R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.affiliation: Henan Key Laboratory of Green Chemical Media and Reactions, School of Chemistry and Chemical Engineering, Henan Normal University , Xinxiang, Henan 453007, P. R. China.|Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University , Xinxiang, Henan 453007, P. R. China.
authors.forename: Huiyong
authors.initials: H
authors.lastname: Wang
authors.affiliation: Henan Key Laboratory of Green Chemical Media and Reactions, School of Chemistry and Chemical Engineering, Henan Normal University , Xinxiang, Henan 453007, P. R. China.|Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University , Xinxiang, Henan 453007, P. R. China.
authors.forename: Jianji
authors.initials: J
authors.lastname: Wang
authors.affiliation: Henan Key Laboratory of Green Chemical Media and Reactions, School of Chemistry and Chemical Engineering, Henan Normal University , Xinxiang, Henan 453007, P. R. China.|Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University , Xinxiang, Henan 453007, P. R. China.
authors.forename: Xiaojia
authors.initials: X
authors.lastname: Guo
authors.affiliation: Henan Key Laboratory of Green Chemical Media and Reactions, School of Chemistry and Chemical Engineering, Henan Normal University , Xinxiang, Henan 453007, P. R. China.|Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University , Xinxiang, Henan 453007, P. R. China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Pei