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该项目将探索界面上吸附有小颗粒的液滴的行为。 当液滴被置于电场中时，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波动的颗粒带。 这些结构在某些条件下可能会变得不稳定，导致弯曲或起皱。 研究人员将通过实验绘制出流体、粒子和电场特性函数所形成的结构。 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，该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断界面的机械特性。 该项目的信息将有助于科学家和工程师设计和加工新颖的胶体产品，例如具有能够响应其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用于在以下条件下构造和操纵胶体颗粒：水滴表面。该项目将建立放置在电场中的液滴上的粒子组装机制，将粒子结构和液滴行为联系起来，以控制场强、粒子和流体特性等参数。 对低颗粒覆盖度的液滴进行实验研究，构建颗粒结构相图，测量颗粒结构对液滴流动变形的影响。 对于高表面覆盖率液滴，液滴变形将用于确定界面的弹性特性。 将使用漏电模型和小变形理论将液滴变​​形和界面的弹性特性联系起来，并预测液滴旋转的电场阈值作为表面电导率的函数。 研究成果将导致具有多功能且可控表面覆盖的新型胶体涂层液滴的工程设计。