Motion of a sphere through a polymer solution
Motion of a sphere through a polymer solution
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DOI：
10.1103/physreve.75.011803
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发表时间：
2007-01-01
影响因子：
2.4
通讯作者：
Tuinier, Remco
中科院分区：
文献类型：
--
作者：
Fan, Tai-Hsi;Dhont, Jan K. G.;Tuinier, Remco
我们给出了球形颗粒通过含有非吸附链条的聚合物溶液时所经历的流体动力阻力的解析解。聚合物耗尽导致颗粒表面附近的聚合物浓度和流体粘度降低。与均匀物性的情况相比，流体相中的非均匀物性会影响平移和旋转球体的输运行为。基于Stokes流函数理论，我们提出了一种简化的两层近似，即用阶跃函数来表示粘度分布。聚合物溶液的存在是根据对球体在纯溶剂中的平动和转动摩擦的修正函数来表示的。结果与系统测量胶体球体通过聚合物溶液时的摩擦力相当一致[Koenderink，Phys.修订本E 69,021804(2004年)]。该分析还根据耗尽层的粘度比和厚度预测了表观滑移长度。
We present analytical solutions of the hydrodynamic resistance force a spherical particle experiences when it moves through a polymer solution containing nonadsorbing chains. Polymer depletion results in a reduced polymer concentration and fluid viscosity near the particle surface. The nonuniform physical properties in the fluid phase affect the transport behavior of a translating and rotating sphere as compared with the case of uniform properties. Based on Stokes' stream function theory, we develop a simplified two-layer approximation by using a step function to represent the viscosity profile. The presence of the polymer solution is formulated in terms of correction functions to the translational and rotational friction of a sphere in a pure solvent. The results are in fair agreement with systematic measurements of the friction of a colloidal sphere when it moves through a polymer solution [Koenderink , Phys. Rev. E 69, 021804 (2004)]. The analysis also predicts an apparent slip length in terms of the viscosity ratio and thickness of the depletion layer.