Active emulsions: Magneto-capillary dynamics of particles at curved interfaces

活性乳液：弯曲界面处颗粒的磁毛细管动力学

基本信息

批准号：
1935228
负责人：
Kyle Bishop
金额：
$ 36.84万
依托单位：
Columbia University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-02-01 至 2023-01-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1935228&HistoricalAwards=false
关键词：
Active emulsions Magneto capillary dynamics

项目摘要

Oil and water don’t mix; however, by stabilizing the interface between them, small droplets of one can be dispersed in the other. These so-called emulsions are commonly found in foods, cosmetics, and pharmaceuticals where mixtures of oil-loving and water-loving molecules must work together to function properly. Surface-active molecules and particles - termed surfactants - adsorb at oil-water interfaces to stabilize emulsions and prevent unmixing. This project aims to create magnet surfactants that use external magnetic fields to power dynamic functions such as mixing and propulsion at the level of individual emulsion droplets. The project will investigate the magnetically driven motions of particles adsorbed at curved interfaces and their use in pumping fluids at the micron-scale. The resulting active emulsions are potentially important for accelerating and/or controlling the rates of drug delivery or chemical reactions within complex fluids. In addition to research training for graduate and undergraduate students, the project will provide educational outreach to middle and high school students from diverse backgrounds. In collaboration with the Inside Engineering initiative, the researchers will develop and implement a laboratory visit curriculum for students from nearby schools in Manhattan and the Bronx. Through hands-on demonstrations and active learning strategies, the program aims to get students excited about the processes of scientific inquiry and engineering design.Rapid particle motions in uniform fields are made possible by coupling magnetic torques to capillary forces at curved interfaces. Building on recent demonstrations of these magneto-capillary dynamics, the project will investigate how time-varying magnetic fields can drive complex particle motions and interfacial flows within and around liquid droplets. The project aims (1) to understand how the waveform of the driving field and the properties of the magnetic particles direct their dynamic motions on curved interfaces; (2) to quantify the transient fluid flows within and around emulsion droplets induced by particle motions; and (3) to identify specific particle types and driving protocols optimized for desired functions such as enhancing mass transfer and propelling droplet motions. These aims will be achieved through a combination of experiments on particle/emulsion systems and modeling of magneto-capillary particle dynamics and fluid flows. The project will examine how these field induced flows can be harnessed for enhancing mass transfer and for propelling drop motions. In contrast to bulk processing of macroscopic emulsions, distributed actuation within active emulsions will enable new strategies for engineering reaction kinetics, mass transport, and separations within multiphase fluids. In pursuit of these functions, automated tools for Bayesian inference, experimental design, and optimization will be developed and deployed to enable the efficient exploration of possible driving fields.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

油和水不混合；但是，通过稳定它们之间的界面，可以将一个小滴分散在另一个液滴中。这些所谓的乳液通常在食品，化妆品和药物中发现，其中喜欢油的分子的混合物必须共同起作用以正常运行。表面活性分子和颗粒 - 称为表面活性剂 - 在油水界面上吸附，以稳定乳液并防止脱落。该项目旨在创建磁性表面活性剂，这些表面活性剂使用外部磁场来动力动态功能，例如在单个乳液液滴水平上混合和推进。该项目将研究装饰在弯曲界面上的颗粒的磁驱动运动，并在微米尺度的泵送流体中使用。所得的活性乳液对于加速和/或控制复杂液体内的药物输送率或化学反应的速率可能很重要。除了为研究生和本科生的研究培训外，该项目还将向来自潜水员背景的中学生提供教育宣传。与内部工程计划合作，研究人员将为曼哈顿附近和布朗克斯大学的学生开发和实施实验室访问课程。通过动手演示和主动学习策略，该计划旨在使学生对科学探究和工程设计的过程感到兴奋。通过将磁性扭矩耦合到弯曲接口处的毛细管力，使均匀场中的粒子粒子运动成为可能。该项目的基础是这些磁性毛细管动力学的最新演示，将研究时间变化的磁场如何驱动复杂的粒子运动和液滴内部和周围的界面流。该项目的目的是（1）了解驱动场的波形和磁颗粒的性能如何引导其动态运动。在弯曲的接口上；（2）量化粒子运动引起的乳液内外的瞬态流动；（3）确定针对所需功能进行优化的特定粒子类型和驱动方案，例如增强传质和推动液滴运动。这些目标将通过在颗粒/乳液系统上的实验以及磁性毛细管颗粒动力学和流体流的建模来实现。该项目将研究如何利用这些场引起的流量来增强传质和推动下降动作。与宏观乳液的批量处理相反，主动乳液中的分布式作用将为工程反应动力学，大规模运输和多相烟道内的分离提供新的策略。为了追求这些功能，将开发和部署用于贝叶斯推理，实验设计和优化的自动化工具，以有效地探索可能的驾驶领域。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响审查标准来通过评估来诚实地支持。