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这个项目将探索在其界面上吸附的小颗粒的液滴行为。 当将液滴放置在电场中时，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粒子带。 在某些情况下，这些结构可能会变得不稳定，从而导致弯曲或皱纹。 研究人员将实验绘制出与流体，粒子和电场特性函数形成的结构。 然后，他们将使用实验结果来开发模型来预测观察到的不稳定性。 当颗粒完全覆盖滴的界面时，界面类似于弹性固体。 液滴形状在流中的变形方式将用于推断界面的机械特性。 该项目的信息将对科学家和工程师设计和处理新型的胶体产品，例如具有可以响应其本地环境的接口的滴剂。漏水液体液滴中的电气流动力流可用于在滴表面结构和操纵胶体颗粒。该项目将在放置在电场中的滴度上建立粒子组件的机理，以将粒子体系结构和滴度行为联系起来，以控制参数，例如场强，粒子和流体特性。 将对具有低颗粒覆盖率的滴剂进行实验研究，以构建粒子结构的相图，并将测量粒子结构对流量滴剂变形的影响。 对于高表面覆盖液，将使用滴剂变形来确定界面的弹性性能。 泄漏的介电模型和小变形理论将用于关联界面的滴形变形和弹性特性，并预测液滴旋转的电场阈值，作为表面电导率的函数。 研究结果将导致具有多功能且可控的表面覆盖的新型胶体涂层液滴的工程。