Xie Yangchun, Yang Tao, Ma Junjun, He Xiaohua
School of Chemistry and Molecular Engineering, East China Normal University, No. 500 Dongchuan Road, Shanghai 200241, China.
Phys Chem Chem Phys. 2021 Dec 15;23(48):27460-27467. doi: 10.1039/d1cp04216e.
A series of Gemini surfactants with an asymmetric structure (PKO 15-3(OH)-; = 12, 14 and 16) were synthesized through a simple two-step reaction consisting of a ring-opening reaction followed by a quaternization reaction. The surface tension measurements indicated that the surface activities of PKO 15-3(OH)- were higher than those of traditional single-chain and symmetrical Gemini surfactants. The thermodynamic parameters obtained from electrical conductivity measurements showed that the micellization processes of PKO 15-3(OH)- were spontaneous and entropy-driven. Transmission electron microscopy and dynamic light scattering measurements confirmed that PKO 15-3(OH)- molecules with a higher asymmetric degree could form vesicles, in which surfactant molecules were interdigitated side-by-side in the vesicle membrane. The obtained results are not in accordance with those calculated from the critical packing theory, which can further complement the theory.
通过由开环反应和季铵化反应组成的简单两步反应，合成了一系列具有不对称结构的 Gemini 表面活性剂（PKO 15-3(OH)-； = 12、14 和 16）。表面张力测量表明，PKO 15-3(OH)- 的表面活性高于传统的单链和对称 Gemini 表面活性剂。由电导率测量获得的热力学参数表明，PKO 15-3(OH)- 的胶束化过程是自发的且由熵驱动。透射电子显微镜和动态光散射测量证实，具有较高不对称度的 PKO 15-3(OH)- 分子可以形成囊泡，其中表面活性剂分子在囊泡膜中并排交错排列。所得结果与根据临界堆积理论计算的结果不一致，这可以进一步补充该理论。
