Hu Yimin, Ge Lingling, Han Jie, Guo Rong
School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, 225002, P. R. China.
Soft Matter. 2015 Jul 28;11(28):5624-31. doi: 10.1039/c5sm01084e.
A highly viscoelastic fluid formed by the ionic liquid-type surfactant 1-hexadecyl-3-nonyl imidazolium bromide ([C16imC9]Br) in water in the absence of any additive was studied. The phase behavior and morphology of aggregates were studied by a combination of rheological techniques, small-angle X-ray scattering (SAXS), cryo-etch-scanning electron microscopy (cryo-etch-SEM) and freeze-fractured transmission electron microscopy (FF-TEM). [C16imC9]Br aqueous solutions showed interesting rheological behavior as a function of both concentration and temperature, which invoked a transition between wormlike micelles and hydrogels. With the increase in [C16imC9]Br concentration, the aqueous solution could form viscoelastic wormlike micelles (50-80 mM), hydrogels (90-110 mM) and wormlike micelles (120-180 mM). As the temperature increased, the hydrogels (90-110 mM) could also transit to wormlike micelles. The unusual phase transition between wormlike micelles and elastic hydrogels was postulated to be the change of the average micellar length.
研究了由离子液体型表面活性剂1-十六烷基-3-壬基溴化咪唑鎓（[C16imC9]Br）在无任何添加剂的水中形成的高粘弹性流体。通过流变技术、小角X射线散射（SAXS）、低温蚀刻扫描电子显微镜（cryo-etch-SEM）和冷冻断裂透射电子显微镜（FF-TEM）相结合的方法研究了聚集体的相行为和形态。[C16imC9]Br水溶液表现出有趣的流变行为，它是浓度和温度的函数，引发了蠕虫状胶束和水凝胶之间的转变。随着[C16imC9]Br浓度的增加，水溶液可形成粘弹性蠕虫状胶束（50 - 80 mM）、水凝胶（90 - 110 mM）和蠕虫状胶束（120 - 180 mM）。随着温度升高，水凝胶（90 - 110 mM）也可转变为蠕虫状胶束。蠕虫状胶束和弹性水凝胶之间不寻常的相变被推测为平均胶束长度的变化。
