Structural Evolution in Cationic Micelles upon Incorporation of a Polar Organic Dopant

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• 作者：Mohit Singh ; Christy Ford ; Vivek Agarwal ; Gerhard Fritz ; Arijit Bose ; Vijay T. John ; and Gary L. McPherson
• 刊名：Langmuir
• 出版年：2004
• 出版时间：November 9, 2004
• 年：2004
• 卷：20
• 期：23
• 页码：9931 - 9937
• 全文大小：641K
• 年卷期：v.20,no.23(November 9, 2004)
• ISSN：1520-5827

文摘

Micelles of cetyltrimethylammonium bromide (CTAB), when doped with increasing levels of 4-ethylphenol,show microstructural transitions from spherical micelles to elongated wormlike micelles, disks, andsubsequently to globular and then to tubular vesicles. Wormlike micelles are observed at a dopant-to-CTAB molar ratio of 1:3. At higher dopant ratios (1:1), globular vesicles are observed which transition totubular vesicles when the dopant becomes the predominant species at a ratio of 3:1. These transitions arereflected in small-angle neutron scattering analysis and, interestingly, can be directly observed throughcryo-transmission electron microscopy. The para-substituted phenol is interfacially active and modulatesinterfacial curvature of the micelles. The observations of microstructure modifications have relevance tothe synthesis of mesoporous materials using CTAB as the template.