Photoresponsive Self-Assembly of Surface Active Ionic Liquid

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• 作者：Aoli Wu ; Fei Lu ; Panpan Sun ; Xinpei Gao ; Lijuan Shi ; Liqiang Zheng
• 刊名：Langmuir
• 出版年：2016
• 出版时间：August 16, 2016
• 年：2016
• 卷：32
• 期：32
• 页码：8163-8170
• 全文大小：463K
• 年卷期：0
• ISSN：1520-5827

文摘

A novel photoresponsive surface active ionic liquid (SAIL) 1-(4-methyl azobenzene)-3-tetradecylimidazolium bromide ([C₁₄mimAzo]Br) with azobenzene located in the headgroup was designed. Reversible vesicle formation and rupture can be finely controlled by photostimuli without any additives in the aqueous solution of the single-tailed ionic liquid. The photoisomerization of the azobenzene derivative was investigated by ¹H NMR and UV–vis spectroscopy. Density functional theory (DFT) calculations further demonstrate that trans-[C₁₄mimAzo]Br has less negative interaction energy, which is beneficial to aggregate formation in water. The incorporation of trans-azobenzene group increases the hydrophobicity of the headgroup and reduces the electrostatic repulsion by delocalization of charge, which are beneficial to the formation of vesicles. However, the bend of cis-azobenzene makes the cis-isomers have no ability to accumulate tightly, which induces the rupture of vesicles. Our work paves a convenient way to achieve controlled topologies and self-assembly of single SAIL.