Shear rheology and porous media flow of wormlike micelle solutions formed by mixtures of surfactants of opposite charge.
Shear rheology and porous media flow of wormlike micelle solutions formed by mixtures of surfactants of opposite charge.
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DOI：
10.1016/j.jcis.2008.07.022
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发表时间：
2008-10
影响因子：
9.9
通讯作者：
Mario Roberto Rojas;A. Müller;A. E. Sáez
中科院分区：
文献类型：
--
作者：
Mario Roberto Rojas;A. Müller;A. E. Sáez
在简单剪切和多孔介质流下，研究了由带相反电荷的表面活性剂混合物（阳离子十六烷基三甲基铵对甲苯磺酸盐，CTAT 和阴离子十二烷基硫酸钠，SDS）形成的蠕虫状胶束溶液在稀释和半稀释状态下的流变学。 CTAT 和 SDS 的水性混合物形成均匀溶液，SDS/CTAT 摩尔比低于 0.12。混合物溶液在剪切粘度方面表现出强烈的协同效应，尤其是在蠕虫状胶束的半稀释状态下，20 mM CTAT 溶液的零剪切速率粘度增加了四个数量级。振荡剪切结果表明 CTAT 蠕虫状胶束的微观结构对 SDS 的添加敏感。添加高达 2 mM SDS 后，20 mM CTAT 溶液的蠕虫状胶束的交叉弛豫时间增加了三个数量级，并且溶液变得越来越有弹性。在剪切流变学中观察到的剪切增稠过程在多孔介质流中变得更加明显，因为流动的拉伸分量诱导形成了更强的协作结构。
The rheology of solutions of wormlike micelles formed by oppositely charged surfactant mixtures (cationic cetyl trimethylammonium p-toluene sulfonate, CTAT, and anionic sodium dodecyl sulfate, SDS), in the dilute and semi-dilute regimes, were studied under simple shear and porous media flows. Aqueous mixtures of CTAT and SDS formed homogeneous solutions for SDS/CTAT molar ratios below 0.12. Solutions of mixtures exhibited a strong synergistic effect in shear viscosity, especially in the semi-dilute regime with respect to wormlike micelles, reaching a four order of magnitude increase in the zero-shear rate viscosity for solutions with 20 mM CTAT. Oscillatory shear results demonstrated that the microstructure of CTAT wormlike micelles is sensitive to SDS addition. The cross-over relaxation times of wormlike micelles of 20 mM CTAT solutions increased by three orders of magnitude with the addition of up to 2 mM of SDS, and the solutions became increasingly elastic. The shear thickening process observed in shear rheology became more pronounced in porous media flow due to the formation of stronger cooperative structures induced by the extensional component of the flow.