Kinetic interpretation of non-newtonian flow
Kinetic interpretation of non-newtonian flow
复制标题
非牛顿流的动力学解释
DOI：
10.1016/0021-9797(70)90068-8
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发表时间：
1970
影响因子：
9.9
通讯作者：
M. M. Cross
中科院分区：
文献类型：
--
作者：
M. M. Cross
在一个简单的动力学处理的基础上解释了分散体系中的剪切稀化行为，该处理涉及初级颗粒之间键的形成和断裂。这导致了形式为η=η∞+(η0-η∞)(1+αDm)的方程，其中η是剪切速率下的粘度D，η0和η∞分别是D=0和D=∞的极限值。参数α=k1k0，其中键断裂的速率常数为k0+k1Dm。在许多分散体系中，布朗运动的贡献与外加剪切的贡献相比可以忽略不计，α变得很大，方程简化为η=η∞+AD−m的形式。指数m表现出对多分散性的依赖，对于单分散体系，指数m有一个单位的上限。在粘弹性体系中，粘性剪切方程的偏差被用来作为评估高剪切速率下的弹性剪切模数的基础。动力学处理的推广得到了一个更一般的方程，适用于也表现出剪切增稠的体系。
Shear thinning behavior in disperse systems is interpreted on the basis of a simple kinetic treatment involving the formation and rupture of linkages between primary particles. This leads to an equation of the form η= η∞+(η 0-η∞)(1+ αD m), where η is the viscosity at shear rate D and η 0 and η∞ are limiting values at, respectively, D= 0 and D=∞. The parameter α= k 1 k 0, where the rate constant for link rupture is k 0+ k 1 D m. In many dispersions the contribution k 0 due to Brownian movement is shown to be negligible compared with that due to applied shear, α becoming very large and the equation reducing to the form η= η∞+ AD− m. The exponent m shows dependence on polydispersity and has an upper limit of unity for a monodisperse system. In a viscoelastic system deviation from the viscosity-shear equation is used as a basis for evaluating the elastic shear modulus at high rates of shear. An extension of the kinetic treatment leads to a more general equation, applicable to systems which also exhibit shear thickening.