title: Photo-induced transformation from wormlike to spherical micelles based on pyrrolidinium ionic liquids.
abstract: A UV-induced self-assembly based on N-methyl-N-cetylpyrrolidinium bromide (C16MPBr) and sodium (4-phenylazo-phenoxy)-acetate (AzoNa) was fabricated in the present work through facile mixing of C16MPBr and trans-AzoNa in water. Due to the trans-cis photoisomerization functionality of the AzoNa, this self-assembly possesses photo-responsive properties. Under ambient conditions, the morphology of the self-assembly was wormlike micelles with a high viscosity of about 10 Pa s, whereas after applying UV light, the self-assembly transformed into spherical micelles with a dramatically lowered viscosity of about 0.01 Pa s. Different from most reported photo-responsive wormlike micelles consisting of conventional cationic surfactant CTAB, our system was constructed from a novel pyrrolidinium ionic liquid. We hope this study may provide a deeper understanding of photo-responsive wormlike micelles constructed by cationic surfactants and photo-sensitive additives in water.
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry, Shandong University, Ministry of Education, Jinan, Shandong 250100, P.R. China. lqzheng@sdu.edu.cn.
authors.forename: Han
authors.initials: H
authors.lastname: Yan
authors.forename: Yue
authors.initials: Y
authors.lastname: Long
authors.forename: Kai
authors.initials: K
authors.lastname: Song
authors.forename: Chen-Ho
authors.initials: CH
authors.lastname: Tung
authors.forename: Liqiang
authors.initials: L
authors.lastname: Zheng