Studies of critical dynamic in a micellar solution

在这项工作中，我们从临界点普适性的观点出发，通过与异丁酸在水中的二元液体混合物的临界动力学进行比较，研究了剪切流存在下非离子胶束溶液的临界动力学。本文的研究结果概括如下：(1)表征水中四甘醇正十二烷基醚在临界混合点附近的临界粘度与剪切速率的关系的指数估计值0.02与Onuki和Kawasaki的理论预测符合得很好。(2)我们从剪切速率和临界涨落寿命的角度考察了粘度的非牛顿行为。在临界点附近测得的粘度服从无量纲变量的类普适函数。(3)从实验上估算了共存曲线内与光散射观测到的剪切有关的特征温度。这两个体系的剪切速率对温度的依赖关系与Onuki和Kawasaki的理论预测符合得很好。我们把这个温度解释为受剪切影响的温度的交叉点。(4)我们在测量的粘度中观察到了剪切变稀和剪切增厚两个区域，这两个区域被特征温度分开。(5)我们用压力跳跃技术研究了异丁酸在水中的相分离混合物中粘度随时间的变化行为。在低剪切速率下的较深淬火下，粘度有了显著的增加。(6)根据剪切淬火对流体的普适函数，考察了剪切敏感胶束溶液的调幅分解动力学，其中剪切速率在共存曲线内降至零。

In this work we have investigated critical dynamics for a nonionic micellar solution in the presence of shear flow by comparing with those for a binary liquid mixture of isobutyric acid in water from viewpoint of critical-point universality. The results obtained in this work have been summarized below.(1)The estimated value of 0.02 for the exponent, which characterizes the shear-rate dependence in the critical viscosity near the critical mixing point of tetra-ethylene glycol n-decylether in water, has been found to agree well with the theoretical prediction of Onuki and Kawasaki.(2)We have examined the non-Newtonian behavior in the viscosity in terms of the shear rate and the life time of critical fluctuations. The measured viscosities near the critical point have been found to obey a universal-like function with a dimensionless variable.(3)We have estimated experimentally a characteristic temperature associated with shear from lightscattering observation inside the coexistence curve. The shear-rate dependence of the temperature for both system here has been found to agree well with the theoretical prediction of Onuki and Kawasaki. We have, interpreted this temperature as to be the crossover one between the shearaffected to, the. shear-unaffected regime inside the coexistence.(4)We have observed in the measured viscosity two regions of shear-thining and shear-thicking, separated by the characteristic temperature.(5)We have investigated the viscosity behavior as a function of time in a phase-separating mixture of isobutyric acid in water using a pressure-jump technique. A significantly large enhancement in the viscosity has been observed in a rather deep-quench under a low shear-rate.(6)The dynamics of spinodal decomposition has been examined for a shear-sensitive micellar solution in terms of a universal function for a fluid by a shear quench, in which the shear rate is dropped to zero inside the coexistence curve.