TPPS和Gemini表面活性剂的复合膜及其手性的研究(英文)

Supramolecular Assembly and Chirality of a Complex Film between Achiral TPPS and a Gemini Surfactant at the Air/water Interface

研究了一种新的gemini表面活性剂(C12H24-α,ω-(C12H25N+(CH3)2Br-)2,(简写为C12-C12-C12)和TPPS在气液界面上形成的复合膜及其手性.实验发现,单独C12-C12-C12不能在纯水表面形成稳定的单分子膜,但当亚相中存在TPPS时,可形成稳定的单分子膜,通过水平提拉法将复合膜转移到固体体基板上,发现在适当的pH值条件下,1TPPS可在复合膜中形成J-聚集体,并且发现,尽管Gemini表面活性剂和TPPS都是非手性的,TPPS的J-聚集体表现出强烈的Cotton效应.另外,gemini表面活性剂的两个正电荷中心对矸IPPS的J-聚集体的手性并不能表现出协同效应。

Supramolecular assembly and chirality between a novel gemini surfactant (C12H24-alpha, omega-(C12H25N (+)(CH3)(2)Br (-))(2), (abbreviated as C-12-C-12-C-12) and TPPS (tetrakis(4-sulfonatophenyl) porphine) at the air/water interface were investigated. It was found that although the gemini surfactant itself could not form a stable monolayer at the air/water interface, when there existed TPPS in the subphase, a stable complex monolayer could be formed. The complex monolayer could be transferred onto solid substrate by a horizontal lifting method. At a certain pH value of the subphase, TPPS could form a J-aggregate. It was further found that the J-aggregate of TPPS showed a strong split Cotton effect in the transferred film although both the gemini surfactant and TPPS are achiral. Further investigation through AFM measurements revealed that the nanothread formed in the transferred film was responsible for the chirality of the multilayer film. In addition, the two positive charge center of the gemini surfactant did not necessarily play the cooperative role in inducing the chirality of TPPS J-aggregate.