Osuji Chinedum O, Kim Chanjoong, Weitz David A
School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2008 Jun;77(6 Pt 1):060402. doi: 10.1103/PhysRevE.77.060402. Epub 2008 Jun 11.
Dilute oil dispersions of fractal carbon black particles with attractive van der Waals interactions display continuous shear thickening followed by shear thinning at high shear rates. The shear thickening transition occurs at gamma c approximately 10(2)-10(3) s(-1) and is driven by hydrodynamic breakup of clusters. Pre-shearing dispersions at shear rates gamma>gamma c produces enhanced-modulus gels where G' approximately sigma pre-shear 1.5-2 and is directly proportional to the residual stress in the gel measured at a fixed sample age. The observed data can be accounted for using a simple scaling model for the breakup of fractal clusters under shear stress.
具有吸引性范德华相互作用的分形炭黑颗粒的稀油分散体在高剪切速率下表现出连续剪切增稠，随后是剪切变稀。剪切增稠转变发生在γc约为10(2)-10(3) s(-1)时，由团簇的流体动力学破裂驱动。在剪切速率γ>γc下预剪切分散体会产生增强模量凝胶，其中G'约为σ预剪切的1.5-2倍，并且与在固定样品龄期测量的凝胶中的残余应力成正比。使用一个简单的标度模型来解释剪切应力下分形团簇的破裂，可以解释观测到的数据。
