Song Ruiying, Du Na, Zhu Xiaoyu, Li Haiping, Song Shue, Hou Wanguo
Key Laboratory of Colloid and Interface Chemistry (Ministry of Education), Shandong University , Jinan 250199, People's Republic of China.
J Phys Chem B. 2015 Mar 5;119(9):3762-7. doi: 10.1021/jp509795v. Epub 2015 Feb 24.
In this paper, we report a micelle-to-vesicle transition in aqueous solution of the anionic single-tailed surfactant (STS) sodium dodecylbenzenesulfonate (SDBS), with the mediation of a rough glass surface (RGS) in the absence of cosurfactants or additives. This transition produced a mixed solution of vesicles and micelles. Interestingly, the obtained SDBS vesicles in the solution displayed good stability during a long-term storage (at least 6 months at room temperature), exposure to high temperature (80 °C for 2 h), and freeze-thawing (-20 or -196 °C for 2 h to approximately 25 °C) after the RGS was removed. Our results confirmed that SDBS could adsorb on the RGS to form bilayers, in which the molecular packing parameter of SDBS was in the range of 1/2-1. The bilayer adsorption and the roughness of the solid surface played an important role in the vesicle formation. In addition, we propose a possible mechanism for the RGS-mediated transition of micelle-to-vesicle in SDBS solutions: SDBS micelles and molecules adsorb on the RGS to form curved bilayers; the curved bilayers detach from the RGS, and then close to form vesicles.
在本文中，我们报道了在不存在助表面活性剂或添加剂的情况下，在粗糙玻璃表面（RGS）的介导下，阴离子单尾表面活性剂（STS）十二烷基苯磺酸钠（SDBS）的水溶液中发生的胶束到囊泡的转变。这种转变产生了囊泡和胶束的混合溶液。有趣的是，在去除RGS后，溶液中获得的SDBS囊泡在长期储存（室温下至少6个月）、高温暴露（80°C 2小时）以及冻融（-20或-196°C 2小时至约25°C）过程中表现出良好的稳定性。我们的结果证实，SDBS可以吸附在RGS上形成双层，其中SDBS的分子堆积参数在1/2 - 1范围内。双层吸附和固体表面的粗糙度在囊泡形成中起重要作用。此外，我们提出了一种在SDBS溶液中RGS介导的胶束到囊泡转变的可能机制：SDBS胶束和分子吸附在RGS上形成弯曲的双层；弯曲的双层从RGS上脱离，然后闭合形成囊泡。
