发表机构
Indian Institute of Technology Kanpur（印度理工学院坎普尔分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究环境流动下多孔结构中胶体的回收，通过有限元模拟表征溶质梯度方向（溶质流出和溶质流入模式）对电泳和渗透胶体提取的影响，揭示不同模式下胶体提取行为及扩散渗透滑移增强作用，为相关领域提供指导。
AI 中文摘要
化学梯度被广泛用于增强多孔介质中的颗粒传输，如洗衣去污和提高石油采收率。扩散泳和扩散渗透分别指胶体和近表面流体响应电解质梯度的运动。这些机制在受限区域的胶体和药物传输中起关键作用。早期工作表明死端微孔中的电泳和渗透传输可通过控制盐梯度方向来控制，但该方向对大规模时空模式和胶体提取的影响未充分探索。本文研究了暴露于环境流动的多孔结构中的电泳和渗透胶体提取。表征了溶质梯度方向的影响，如溶质流出和溶质流入模式。二维多孔结构由排列成晶格有序六边形堆积且间距相等的多个柱体/纤维组成。有限元模拟结果表明，电泳胶体提取在两种模式下表现出质的不同行为：在溶质流出模式下，胶体从多孔结构的周边区域提取；在溶质流入模式下，提取主要发生在停滞核心。柱体/纤维内表面的扩散渗透滑移进一步增强了两种模式下的提取，溶质流入模式下由于内部时空流动模式增强相对更大。这些见解可指导增强膜过滤、洗衣去污和提高石油采收率。
英文摘要
Chemical gradients are widely employed to enhance particle transport in porous media, such as laundry detergency and enhanced oil recovery. Diffusiophoresis and diffusioosmosis refer to the movement of colloid and movement of near-surface fluid in response to electrolyte gradients, respectively. These mechanisms play a crucial role in colloid and drug transport in constricted regions where bulk transport is infeasible. Our earlier work [Tiwari et al., Langmuir 41, 18583 (2025)] has shown that phoretic and osmotic transport in dead-end micro-pores can be controlled by orienting salt gradients into or out of the pores; however, the extent to which this orientation influences large-scale spatiotemporal patterns and colloid extraction is not thoroughly explored. In this work, we study the phoretic and osmotic colloidal extraction from porous structure exposed to an ambient flow. We characterize the impact of solute gradient orientation, such as solute-out (i.e., solute-emitting porous media) and solute-in (i.e., solute-consuming media) modes. The two-dimensional porous structure is made of a number of pillars/fibers arranged in a lattice ordered hexagonal packing with equal spacing. The results from finite-element simulations show that phoretic colloidal extraction exhibits a qualitatively distinct behavior in the two modes: in the solute-out mode, colloids are extracted from the peripheral region of the porous structure, whereas in the solute-in mode, extraction predominantly occurs from the stagnant core. Diffusioosmotic slip on the internal surface of pillars/fibres further amplifies extraction in both modes, with a relatively larger enhancement in the solute-in mode due to internal spatiotemporal flow patterns. Beyond demonstrating the sensitivity of osmotic transport in porous media, these insights can guide enhanced membrane filtration, laundry detergency, and enhanced oil recovery.
Comments20 figures with supplementary material
