CAREER: Electrokinetic Flows and Electrochemical Dynamics in Concentrated Electrolytes and Ionic Liquids

职业：浓电解质和离子液体中的电动力学流动和电化学动力学毕业院校：卡耐基梅隆大学技术和生物学中的许多液体和粒子系统都含有离子，在其中一些系统中，离子的浓度很大。科学家和工程师用来预测这些系统动力学的理论是基于离子可以被认为是点电荷以及离子之间的相互作用不重要的假设。基于这一理论的方程在离子浓度较低的情况下工作得很好，但它们无法预测离子浓度较大时观察到的有趣现象。含有高浓度离子的系统出现在许多重要的技术和生物学问题中，包括海水淡化、电池和超级电容器的开发以及离子通过离子通道在细胞膜上的转移。该项目的目标是开发一个综合的研究和教学计划，以开发一个新的模型，科学家和工程师可以用它来描述集中系统中电力驱动运输的基本特征。理解这些现象并训练学生欣赏它们将提高制造能力，并可能导致新技术的发展，例如基于带电物体运动的纳米颗粒和生物分子的新分离方案。该项目的多层次教育计划包括外展活动、本科和研究生课程设计和研究、技术软件开发和科学会议组织。该项目将通过建模、计算和实验相结合，为浓电解质和离子液体中的电驱动（电动）流体流动和粒子输运开发一个连续体框架。浓缩电解质和离子液体是能量存储和转换技术中有吸引力的材料，但现有的理论模型无法描述它们对外加电压的动态响应。该项目的中心假设是，由于空间排斥力和静电相关性，浓缩系统中的显式离子-离子相互作用导致其动力学与稀溶液截然不同。分子模拟可以量化平衡体系中的离子-离子相互作用；然而，它们通常在计算上过于昂贵，无法捕捉电动现象。因此，迫切需要一种连续水平理论来概括复杂几何结构中浓载电荷液体的非平衡输运的基本特征。一个模型将开发异常的电动运输在集中系统，包括电泳迁移逆转。在浓缩电解质和离子液体中，粒子之间的静电力将被量化，以预测这些介质中的悬浮稳定性和絮凝性。分析了离子液体的电化学动力学。

CAREER: Electrokinetic Flows and Electrochemical Dynamics in Concentrated Electrolytes and Ionic LiquidsPI: Khair, AdityaInstitution: Carnegie Mellon UniversityMany liquid and particle systems in technology and biology contain ions, and in some of these systems, the concentration of ions is large. The theory that scientists and engineers use to predict the dynamics of these systems is based on assumptions that the ions can be considered to be point charges and that interactions among the ions are not important. The equations based on this theory work well for dilute ion concentrations, but they fail to predict interesting phenomena observed when the concentration of ions is large. Systems containing high concentrations of ions appear in many problems of technological and biological importance, including water desalination, the development of batteries and super-capacitors, and transfer of ions across cell membranes through ion channels. The goal of this project is to develop an integrated research and teaching program to develop a new model that scientists and engineers can use to describe the essential features of electrically driven transport in concentrated systems. Understanding such phenomena and training students to appreciate them will enhance manufacturing capabilities and may lead to new technological developments such as novel separation protocols for nanoparticles and biomolecules based on the motion of charged objects. The multi-tiered educational plan for the project includes outreach activities, undergraduate and graduate course design and research, technical software development, and organization of scientific meetings.This project will develop a continuum framework for electrically driven (electrokinetic) fluid flow and particle transport in concentrated electrolytes and ionic liquids, via a combination of modeling, computation, and experiment. Concentrated electrolytes and ionic liquids are attractive materials for energy storage and conversion technologies, but existing theoretical models fail to describe their dynamical response to applied voltages. The central hypothesis of the project is that explicit ion-ion interactions in concentrated systems, due to steric repulsion and electrostatic correlations, result in their dynamics being radically different from dilute solutions. Molecular simulations can quantify ion-ion interactions in equilibrium systems; however, they are often too computationally expensive to capture electrokinetic phenomena. Thus, there is a pressing need for a continuum-level theory that encapsulates the essential features of nonequilibrium transport in concentrated charge-carrying liquids in complex geometries. A model will be developed for anomalous electrokinetic transport in concentrated systems, including electrophoretic mobility reversals. The electrostatic forces between particles in concentrated electrolytes and ionic liquids will be quantified to predict suspension stability and flocculation in these media. The electrochemical dynamics of ionic liquids will be analyzed.