Microstructure and rheology of soft to rigid shear-thickening colloidal suspensions
Microstructure and rheology of soft to rigid shear-thickening colloidal suspensions
复制标题
DOI：
10.1122/1.4931655
复制
发表时间：
2015-11-01
影响因子：
3.3
通讯作者：
Maia, Joao
中科院分区：
文献类型：
--
作者：
Jamali, Safa;Boromand, Arman;Maia, Joao
本文用计算模型研究了软-硬胶体悬浮液的剪切速率依赖性流变特性。我们表明，接触力定义的基础上的弹性流体动力学变形理论捕捉一个重要的流变行为的胶体悬浮液：虽然近硬球颗粒表现出强大的和连续的剪切增稠的演变到一个恒定的粘度状态，软悬浮液进行第二次剪切变稀制度在高Peclet数时，流体动力学应力变得大于胶体颗粒的模量。我们测量N-1和N-2是大的和负的剪切增稠制度，然而，软球在第二次剪切变稀的N-2的幅度减小，并最终成为积极的。我们发现，对于近硬球悬浮液，胶体压力，剪切应力和法向应力差系数趋于发散附近的最大包装分数，而P >西格玛> N-1 > N-2。(C)2015年，美国流变学会（Society of Rheology）
The shear rate-depentdent rheological properties of soft to rigid colloidal suspensions are studied using computational models. We show that a contact force defined based on an elasto-hydrodynamic deformation theory captures an important rheological behavior of colloidal suspensions: While near hard-sphere particles exhibit a strong and continuous shear thickening the evolves to a constant viscosity state, soft suspensions undergo a second shear-thinning regime at high Peclet numbers when the hydrodynamic stresses become larger than the modulus of the colloidal particles. We measure N-1 and N-2 to be large and negative in the shear-thickening regime; however, for soft spheres at the onset of second shear-thinning N-2 reduces in magnitude and eventually becomes positive. We show that for near hard-sphere suspensions, colloidal pressure, shear stress, and normal stress difference coefficients tend to diverge near the maximum packing fraction while P > sigma > N-1 > N-2. (C) 2015 The Society of Rheology.