Wormlike micelles in poly(oxyethylene) surfactant solution: Growth control through hydrophilic-group size variation
Wormlike micelles in poly(oxyethylene) surfactant solution: Growth control through hydrophilic-group size variation
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DOI：
10.1016/j.jcis.2008.07.055
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发表时间：
2008-11-01
影响因子：
9.9
通讯作者：
Aramaki, Kenji
中科院分区：
文献类型：
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作者：
Ahmed, Toufiq;Aramaki, Kenji
在聚氧乙烯胆甾醇醚（ChEO（m），m = 15，30）水溶液中加入三乙二醇单十二烷基醚（C12 EO 3）形成粘弹性胶束溶液。该体系的稳态剪切和动态流变行为具有蠕虫状胶束溶液的特征。在任一体系中，发现平台模量（G（0））和弛豫时间（τ）随着助表面活性剂混合分数的增加而增加。ChEO（30）-C12 EO_3体系在最大粘度区的平台模量高于ChEO（15）-C12 EO_3体系在最大粘度区的平台模量，而弛豫时间则与ChEO（30）-C12 EO_3体系在最大粘度区的平台模量相反，两个体系的最大粘度在同一数量级。在ChEO（30）-C12 EO 3体系中，当助表面活性剂的混合分数高于ChEO（15）-C12 EO 3体系时，体系的粘度最大。可以得出结论，减少亲水性表面活性剂的头基大小有利于胶束的生长。甘油单月桂酸酯是另一种已知在某些体系中诱导生长的疏水性表面活性剂，发现在ChEO（m）溶液中发生显著胶束生长之前会导致相分离，尽管发现ChEO（m）的头基大小的影响与ChEO（m）-C12 EO 3体系相似。(C)2008年爱思唯尔公司All rights reserved.
Viscoelastic micellar solutions are formed in poly(oxyethylene) cholesteryl ether (ChEO(m), m = 15, 30) aqueous solutions on addition of tri(ethyleneglycol) mono n-dodecyl ether (C12EO3). The steady-shear and dynamic theological behavior of the systems is characteristic of wormlike micellar solution. In either system, the plateau modulus (G(0)) and relaxation time (tau) are found to increase with increasing cosurfactant mixing fractions. The plateau modulus of the ChEO(30)-C12EO3 system at the maximum Viscosity region is found to be higher than that in the ChEO(15)-C12EO3 system at the maximum viscosity region, whereas for the relaxation time the opposite relation is found. The maximum viscosities obtained in the two systems are of the same order of magnitude. In the ChEO(30)-C12EO3 system, the maximum viscosity is obtained at a higher cosurfactant mixing fraction than that in the ChEO(15)-C12EO3 system. It is concluded that decreasing the head-group size of the hydrophilic surfactant favors micellar growth. Monolaurin, another hydrophobic surfactant known to induce growth in some systems, is found to cause phase separation before significant micellar growth occurs in ChEO(m) solutions, although the effect of head-group size of ChEO(m) is found to be similar to the ChEO(m)-C12EO3 systems. (C) 2008 Elsevier Inc. All rights reserved.