Presidential Young Investigators Award: Mechanistic Studies of Colloidal Interactions

这项由PYI指导的研究计划的重点将是胶体颗粒及其运输相关的焦点。最重要的一种力是电动升力，它是由带电物体在电解液溶液中的相对运动引起的。电动升力对所有颗粒传输过程都具有重要意义，包括流体动力层析、深床过滤、悬浮液流变学以及流体流动过程中颗粒从表面分离。考虑到电动升力的广泛适用性，评估电动升力在特定系统中的重要性是至关重要的。以前对这种力的分析主要集中在两个具有薄而平衡的双层的物体上。这些简化的模型虽然在理论上很容易定性，但在技术上并不相关。例如，分析表明，电动升力在非水介质中更为重要，非水介质具有厚的、非平衡的双层结构的特点。PI将启动对这种力的深入分析，首先消除平衡双层限制，其次是薄双层限制。这些理论研究将与升力的实验观测相结合。稍后，传输研究将扩展到胶体力在分散体流变学中的作用，并应用于涂料和薄膜。这项工作的结果将极大地丰富对胶体颗粒输运的基本认识。

The focus of this PYI-directed research program will be on colloidal particles and the focus associated with their transport. One force of fundamental interest is electrokinetic lift, which arises from the relative motion of charged bodies in electrolyte solutions. Electrokinetic lift is significant to all particle transport processes including hydrodynamic chromatography, deep-bed filtration, suspension rheology, and the detachment of particles from surfaces during fluid flow. Given the broad applicability of this force, it is essential that one assesses the importance of electrokinetic lift in a given system. Previous analyses of this force have focused on two bodies bearing thin, equilibrium double layers. Such simplified models, while easy to theoretically characterize, are not technologically relevant. For example, the analyses have shown that electrokinetic lift is more important in nonaqueous media, which are characterized by thick, nonequilibrium double layers. The PI will initiate an in- depth analysis of this force, removing first the equilibrium double-layer restriction and, second, the thin double-layer restriction. These theoretical studies will be coupled with experimental observation of lift. Later, transport studies will then be extended to focus on the role of colloidal forces in the rheology of dispersions with application to coatings and films. The results of this work will greatly enrich the fundamental understanding of the transport of colloidal particles.