Electrohydrodynamics of particle-covered drops

颗粒覆盖液滴的电流体动力学

• 批准号: 1437545
• 负责人: Petia Vlahovska
• 金额: $ 31.54万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1437545&HistoricalAwards=false
• 关键词: Electrohydrodynamics; particle; covered; drops

CBET 1437545This project will explore the behavior of liquid drops that have small particles adsorbed on their interfaces. When the drops are placed in an electric field, the particles on the interface can assemble into a variety of interesting structures, including particle belts that rotate and undulate around the drop. These structures can become unstable in some conditions, leading to bucking or wrinkling. The investigators will experimentally map out the structures that form as a function of fluid, particle, and electric field properties. Then, they will use the experimental results to develop a model to predict the observed instabilities. When the particles completely cover the interface of the drop, the interface resembles an elastic solid. The way the drop shape deforms in flow will be used to deduce the mechanical characteristics of the interface. The information from this project will be useful to scientists and engineers to design and process novel colloidal products such as drops with interfaces that can respond to their local environment.Electrohydrodynamic flow in leaky-dielectric liquid drops can be used to structure and manipulate colloidal particles at the drop surface. This project will establish the mechanisms of particle assembly on a drop placed in an electric field to relate particle architectures and drop behavior to control parameters such as field strength, particle and fluid properties. Experimental studies will be carried out for drops with low particle coverage to construct a phase diagram of particle structures and the influence of particle structure on drop deformation in flow will be measured. For high surface coverage drops, drop deformation will be used to determine elastic properties of the interface. A leaky dielectric model and small deformation theory will be used to relate drop deformation and elastic properties of the interface and to predict the electric field threshold for rotation of the drops as a function of surface conductivity. The research outcomes will lead to the engineering of novel colloidal-coated drops with versatile and controllable surface coverage.

CBET 1437545本项目将探索具有吸附在其界面上的小颗粒的液滴的行为。 当液滴置于电场中时，界面上的颗粒可以组装成各种有趣的结构，包括围绕液滴旋转和起伏的颗粒带。 这些结构在某些情况下会变得不稳定，导致屈曲或弯曲。 研究人员将通过实验绘制出作为流体，粒子和电场特性函数的结构。 然后，他们将利用实验结果开发一个模型来预测观察到的不稳定性。 当颗粒完全覆盖液滴的界面时，界面类似于弹性固体。 液滴形状在流动中变形的方式将用于推导界面的机械特性。 该项目的信息将有助于科学家和工程师设计和加工新型胶体产品，例如具有能够响应局部环境的界面的液滴。漏介电液滴中的电流体动力学流动可以用于结构化和操纵液滴表面的胶体颗粒。该项目将建立放置在电场中的液滴上的颗粒组装机制，以将颗粒结构和液滴行为与控制参数（如场强、颗粒和流体性质）联系起来。 将对低颗粒覆盖率的液滴进行实验研究，以构建颗粒结构的相图，并测量颗粒结构对液滴在流动中变形的影响。 对于高表面覆盖率的液滴，液滴变形将用于确定界面的弹性性质。 一个泄漏的电介质模型和小变形理论将被用来关联液滴变形和界面的弹性特性，并预测作为表面电导率的函数的液滴旋转的电场阈值。 研究成果将导致工程的新型胶体涂层滴与通用和可控的表面覆盖。