Kornev Konstantin G, Neimark Alexander V
Center for Modeling and Characterization of Nanoporous Materials, TRI/Princeton, P.O. Box 625, Princeton, NJ 08542, USA.
J Colloid Interface Sci. 2003 Jun 1;262(1):253-62. doi: 10.1016/S0021-9797(03)00072-9.
A theoretical model was developed to describe the dynamics of spontaneous penetration of viscoelastic fluids into capillaries. The model agrees quantitatively with recent experiments on absorption of droplets of polymer solutions by glass capillaries [A.V. Bazilevsky, K.G. Kornev, A.N. Rozhkov, A.V. Neimark, J. Colloid Interface Sci. (2003)]. The rate of penetration progressively reduces with the increase in fluid elasticity. Analysis revealed two main contributions to the viscoelastic drag of the liquid column: (i) viscous resistance, which is independent of fluid elasticity, and (ii) viscoelastic resistance, known as the Weissenberg effect. We analytically derived an augmented Bosanquet equation for the maximal velocity of penetration by balancing capillary, inertia, and viscoelastic forces. For slow creep of a liquid column, the Lucas-Washburn equation was modified by accounting for the Weissenberg effect. A series of numerical calculations were performed to demonstrate characteristic features of absorption of fluids at different conditions. This article also discusses some problems specific to absorption of biofluids. We show that deformations of cell membranes in the external converging flow may cause their rupture at the pore entrance.
建立了一个理论模型来描述粘弹性流体自发渗透到毛细管中的动力学过程。该模型与最近关于玻璃毛细管吸收聚合物溶液液滴的实验结果在定量上是一致的[A.V. 巴齐列夫斯基、K.G. 科尔涅夫、A.N. 罗日科夫、A.V. 涅伊马克，《胶体与界面科学杂志》(2003年)]。渗透速率随着流体弹性的增加而逐渐降低。分析揭示了液柱粘弹性阻力的两个主要来源：(i) 粘性阻力，它与流体弹性无关；(ii) 粘弹性阻力，即韦森堡效应。通过平衡毛细管力、惯性力和粘弹性力，我们解析推导了一个用于最大渗透速度的扩展博赞奎特方程。对于液柱的缓慢蠕变，通过考虑韦森堡效应修正了卢卡斯 - 沃什伯恩方程。进行了一系列数值计算以展示不同条件下流体吸收的特征。本文还讨论了生物流体吸收所特有的一些问题。我们表明，外部收敛流中细胞膜的变形可能导致其在孔口处破裂。
