Zaman AA, Moudgil BM
Engineering Research Center for Particle Science and Technology
J Colloid Interface Sci. 1999 Apr 1;212(1):167-175. doi: 10.1006/jcis.1998.6049.
The flow behavior of bidisperse aqueous silica suspensions has been studied at different electrolyte concentrations as a function of shear rate, total volume fraction of the particles, and volume ratio of small to large particles. It is shown that the range of the electrostatic repulsion plays an important role in determining the viscosity of the suspension. Binary mixtures of particles of longer range repulsive forces showed higher viscosities than the suspensions of shorter range electrostatic interactions. Bimodal suspensions of long-range interactions showed non-Newtonian behavior over wider ranges of shear due to the deformation of the ionic cloud around the particles, which is larger in these systems. The viscosity of bimodal suspensions used in this study was scaled with respect to the viscosity of the related monosized systems and the viscosity of one bimodal suspension at a fixed total volume fraction of the particles, employing our earlier scaling method. The model normalizes the effect of colloidal forces by introducing a scaling factor that collapses the data into a single curve for bimodal suspensions of a particular size ratio, and it is shown that the model is valid for systems with both short-range and long-range repulsive forces. Copyright 1999 Academic Press.
研究了不同电解质浓度下双分散二氧化硅水悬浮液的流动行为，该行为是剪切速率、颗粒总体积分数以及小颗粒与大颗粒体积比的函数。结果表明，静电排斥范围在决定悬浮液粘度方面起着重要作用。具有较长程排斥力的颗粒二元混合物比具有较短程静电相互作用的悬浮液表现出更高的粘度。由于颗粒周围离子云的变形，长程相互作用的双峰悬浮液在更宽的剪切范围内表现出非牛顿行为，在这些系统中这种变形更大。本研究中使用的双峰悬浮液的粘度相对于相关单尺寸系统的粘度以及在固定颗粒总体积分数下一种双峰悬浮液的粘度进行了标度，采用了我们早期的标度方法。该模型通过引入一个标度因子来归一化胶体力的影响，该因子将特定尺寸比的双峰悬浮液的数据合并为一条单一曲线，结果表明该模型对具有短程和长程排斥力的系统均有效。版权所有1999年学术出版社。
