Benet Eduard, Vernerey Franck J
Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado 80309-0427, USA.
Phys Rev E. 2016 Dec;94(6-1):062613. doi: 10.1103/PhysRevE.94.062613. Epub 2016 Dec 29.
The permeation and trapping of soft colloidal particles in the confined space of porous media are of critical importance in cell migration studies, design of drug delivery vehicles, and colloid separation devices. Our current understanding of these processes is however limited by the lack of quantitative models that can relate how the elasticity, size, and adhesion properties of the vesicle-pore complex affect colloid transport. We address this shortcoming by introducing a semianalytical model that predicts the equilibrium shapes of a soft vesicle driven by pressure in a narrow pore. Using this approach, the problem is recast in terms of pressure and energy diagrams that characterize the vesicle stability and permeation pressures in different conditions. We particularly show that the critical permeation pressure for a vesicle arises from a compromise between the critical entry pressure and exit pressure, both of which are sensitive to geometrical features, mechanics, and adhesion. We further find that these results can be leveraged to rationally design microfluidic devices and diodes that can help characterize, select, and separate colloids based on physical properties.
软胶体颗粒在多孔介质受限空间中的渗透和捕获在细胞迁移研究、药物递送载体设计及胶体分离装置中至关重要。然而,我们目前对这些过程的理解受到限制,因为缺乏能够关联囊泡 - 孔复合体的弹性、大小和粘附特性如何影响胶体运输的定量模型。我们通过引入一个半解析模型来解决这一缺陷,该模型可预测在狭窄孔隙中由压力驱动的软囊泡的平衡形状。使用这种方法,该问题被重新表述为压力和能量图,这些图表征了不同条件下囊泡的稳定性和渗透压力。我们特别表明,囊泡的临界渗透压力源于临界进入压力和退出压力之间的折衷,这两者都对几何特征、力学和粘附敏感。我们进一步发现,这些结果可用于合理设计微流控装置和二极管,有助于根据物理性质表征、选择和分离胶体。