Morphological transitions in aqueous CTAB–NaDC system: Macroscopic and microscopic studies
Morphological transitions in aqueous CTAB–NaDC system: Macroscopic and microscopic studies
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DOI：
10.1016/j.molliq.2013.10.020
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发表时间：
2014-02
影响因子：
6
通讯作者：
Sanjeev Kumar;H. Patel
中科院分区：
文献类型：
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作者：
Sanjeev Kumar;H. Patel
The effect of addition of a bile salt, sodium deoxycholate (NaDC), on the morphological transition in aqueous cetyl trimethylammonium bromide (CTAB) has been studied by various macroscopic and microscopic techniques. Visual, optical density and zero-shear viscosity data of the aqueous mixtures provide some basic macroscopic information on phase behavior. Various phase transitions are observed as we increase the [NaDC] and system even passes through the precipitation region followed by an appearance of clear fluid again. Before and after precipitation region, systems show bluish appearance indicating the presence of vesicles, which was supported by rheological and dynamic light scattering data. It was interesting to note that vesicles were present in the solution when the mole fraction of one of the components was ~ 0.55. This suggests the requirement of the charge for vesicle formation and stabilization. NMR spectra show the peak broadening on increasing the [NaDC] in the system confirming the presence of a mixture of micelles and vesicles. The presence of vesicles in few samples of CTAB–NaDC aqueous mixture was further confirmed by polarizing and transmission electron microscopy. Bigger morphologies were observed at pH = 9.2 (than in pure water). Such morphological transitions may have utility in range of areas, including viscosity enhancer, template for nanostructures and as models for biological assemblies.
