Presidential Young Investigators Award: Mechanistic Studies of Colloidal Interactions

这个由pyi指导的研究项目的重点将放在胶体颗粒及其运输相关的焦点上。一种最重要的力是电动升力，它是由电解质溶液中带电体的相对运动引起的。在流体流动过程中，包括流体动力色谱、深床过滤、悬浮流变性和颗粒从表面分离在内的所有颗粒输运过程中，电动升力都是重要的。鉴于这种力的广泛适用性，有必要评估在给定系统中电动升力的重要性。先前对这种力的分析主要集中在两个承载薄的平衡双层的物体上。这种简化的模型虽然在理论上易于描述，但在技术上并不相关。例如，分析表明，在非水介质中，电动升力更为重要，因为非水介质具有厚的非平衡双层结构。PI将开始对这种力进行深入的分析，首先取消平衡双层限制，其次取消薄双层限制。这些理论研究将与升力的实验观察相结合。随后，运输研究将扩展到关注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粒子输运的基本认识。

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.