School of Chemistry and Chemical Engineering, Yangzhou University , Jiangsu Province 225002 People's Republic of China.
J Phys Chem B. 2013 Dec 5;117(48):15014-22. doi: 10.1021/jp405838v. Epub 2013 Nov 22.
The aggregation of ionic liquid-based double-tailed surfactant, 1,3-dioctylimidazolium bromide ([Doim]Br) and its interaction with pluronic copolymer F127 were systematically investigated by nuclear magnetic resonance (NMR), surface tension, dynamic light scattering (DLS), and isothermal titration calorimetry (ITC). It was found that the [Doim]Br aggregates are composed with the alkyl chains embedded in the micellar core and with the imidazolium rings parallel and staggered on the hydrophilic layer of micelles, which was generally different from the single-tailed IL [omim]Br. The hydrogen bonding between protons attached to the imidazolium rings and anion Br(-) was enhanced upon the aggregation of [Doim]Br. The aggregation of F127 was promoted by addition of [Doim]Br, which was more efficient than the single-tailed surfactant. At lower [Doim]Br content, [Doim]Br monomers embedded deeply into F127 micelle core. At higher [Doim]Br concentrations, the F127 micelles were disassociated, and then F127 chains penetrated into [Doim]Br micelle. In addition, the microstructure of F127/[Doim]Br complex can also be tuned by temperature.
采用核磁共振波谱（NMR）、表面张力、动态光散射（DLS）和等温热量滴定（ITC）等手段系统地研究了离子液体双尾表面活性剂 1,3-二辛基咪唑溴盐（[Doim]Br）的聚集行为及其与两亲性嵌段共聚物 F127 的相互作用。结果表明，[Doim]Br 胶束由嵌入胶束核的烷基链和与胶束亲水层平行且交错的咪唑环组成，这与单尾 IL [omim]Br 通常不同。[Doim]Br 聚集时，附着在咪唑环上的质子与阴离子 Br(-)之间的氢键增强。添加[Doim]Br 促进了 F127 的聚集，其效率高于单尾表面活性剂。在较低的[Doim]Br 浓度下，[Doim]Br 单体深嵌入 F127 胶束核内。在较高的[Doim]Br 浓度下，F127 胶束解离，然后 F127 链渗透到[Doim]Br 胶束中。此外，F127/[Doim]Br 复合物的微观结构也可以通过温度进行调节。
