文献类型：期刊文献

英文题名：The formation and properties of multilamellar vesicles in Gemini/SDS/H₂O system

作者：Shang, YZ; Xu, Y; Liu, HL; Hu, Y

机构：[1]E China Univ Sci & Technol, Dept Chem, Shanghai 200237, Peoples R China

年份：2006

卷号：27

期号：1

起止页码：105

外文期刊名：JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000233639300016)】；

语种：英文

外文关键词：gemini surfactant; traditional surfactant; multilamellar vesicle; synergistic effect; dissipative particle dynamics (DPD)

摘要：Self-assembled vesicles have drawn much research attention in recent years for their special structure. The vesicles formed in mixed solutions of gemini surfactant 12-3-12,2Br - and traditional surfactant SDS are explored with both experiments and computer simulation. The morphology characterization is done via transmission electron microscopy (TEM) combined with freeze-etching or negative-staining technique. Introduced as a mesoscopic approach, dissipative particle dynamics (DPD) simulation is carried out for the system under study to inspect the surfactants' aggregate process and reveal how the vesicles are formed. The results show that almost all vesicles in this system are multilamellar. However, there are intrinsic differences between this kind of multilamellar vesicle and multilamellar vesicles formed in a mixed system of traditional cationic and anionic surfactants. All of the differences should be attributed to the unique molecular structure of the gemini surfactant and the stronger synergistic effect of the cationic gemini surfactant and a traditional anionic surfactant. The mechanism of the formation of vesicles with special structure was explored, indicating two mechanisms for forming the multilamellar vesicles in this system. One is the aggregation of unilamellar vesicles, while the other is very complicated with a series of distortions, from long rod-like micelles to short rod-like micelles. Subsequently those micelles fuse together into cylindrical clusters, which curl to form loops and at the same time encapsulate water molecules. This minimizes contact area and leads to further drop of surface energy; finally, the "bowl-like aggregation encloses, and a stable vesicle is established.