The effect of head group of surfactant on the self-assembly structures and aggregation transitions, which had rarely been reported in mixed aqueous solutions of cationic surfactant and anionic surfactant-like ionic liquid molecules, was studied in three different cases. We have investigated the effect of the methyl, ethyl and 2-phenoxy-ethyl on the aggregation by the methods of turbidity, dynamic light scattering (DLS), transmission electron microscopy (TEM), rheological measurements, and steady-state fluorescence measurements. It is found that the head group has an important effect on the self-assembly structures and phase transition behaviors of mixed aqueous solutions. The ethyl group introduces a more considerable steric hindrance compared with the methyl group, which leads to the smaller packing parameter. Therefore, the system containing the methyl group has a slightly larger vesicle phase range than the system containing the ethyl group. However, compared with the ethyl group, 2-phenoxy-ethyl introduces the non-covalent pi-pi interaction between the imidazolium ring and benzene ring. This interaction easily eliminates the steric hindrance. Therefore, it is more prone to form the wormlike micelles and vesicles for the system with the 2-phenoxy-ethyl group. We also find intriguing rheological behavior from the non-spherical vesicles. Moreover, for the wormlike micelles, we find it only form in aqueous surfactant mixtures with strong interactions.

在三种不同的情况下，研究了表面活性剂头基对自组装结构和聚集转变的影响，这在阳离子表面活性剂和类似阴离子表面活性剂的离子液体分子的混合水溶液中鲜有报道。我们已经通过浊度，动态光散射（DLS），透射电子显微镜（TEM），流变学测量和稳态荧光测量的方法研究了甲基，乙基和2-苯氧基乙基对聚集的影响。发现头基对混合水溶液的自组装结构和相变行为具有重要影响。与甲基相比，乙基引入更大的空间位阻，从而导致较小的堆积参数。因此，含有甲基的体系的囊泡相范围比含有乙基的体系略大。然而，与乙基相比，2-苯氧基-乙基在咪唑鎓环和苯环之间引入了非共价的π-π相互作用。这种相互作用很容易消除空间位阻。因此，对于具有2-苯氧基-乙基的体系，更容易形成蠕虫状的胶束和囊泡。我们还从非球形囊泡中发现了有趣的流变行为。此外，对于蠕虫状胶束，我们发现它仅在具有强相互作用的水性表面活性剂混合物中形成。2-苯氧基-乙基引入咪唑鎓环和苯环之间的非共价pi-pi相互作用。这种相互作用很容易消除空间位阻。因此，对于具有2-苯氧基-乙基的体系，更容易形成蠕虫状的胶束和囊泡。我们还从非球形囊泡中发现了有趣的流变行为。此外，对于蠕虫状胶束，我们发现它仅在具有强相互作用的水性表面活性剂混合物中形成。2-苯氧基-乙基引入咪唑鎓环和苯环之间的非共价pi-pi相互作用。这种相互作用很容易消除空间位阻。因此，对于具有2-苯氧基-乙基的体系，更容易形成蠕虫状的胶束和囊泡。我们还从非球形囊泡中发现了有趣的流变行为。此外，对于蠕虫状胶束，我们发现它仅在具有强相互作用的水性表面活性剂混合物中形成。