Capillary Diodes with Selective Oil-Water Wetting Dynamics

1605809 Colosqui，Carlos本项目将研究一种分离水和油的创新方法，通常定义为不溶于水的有机化合物，通过调节工程多孔介质中排水/去湿动力学和吸收动力学。该项目将提高在具有复杂纳米和微米结构的“真实”表面上(动态)润湿和液体粘合的基础知识。这些新知识将推动防污、减阻和微/纳米流体处理技术的发展，对美国的经济、基础设施和环境产生重大影响。PI最近的理论发展表明，润湿过程的动力学呈现出传统的基于连续介质和确定性预测所不能描述的非平凡状态。这些理论预测得到了分子动力学模拟的证实，最近，PI小组和其他小组的实验工作也证实了这一点。在这些发展的基础上，该项目将研究利用新现象的可行性，例如从毛细管驱动的湿润到热激活润湿的交叉，以用于创新的技术应用。具体研究目标的实现将得益于主计生和合作主计长的跨学科和互补性技能。为了理解这一点，需要考虑接触线的热运动的影响，当接近机械平衡时，接触线的热运动主导了动力学。该项目旨在产生所需的基础知识，以了解和控制在纳米/微结构介质中自发和强制吸水或排水的动力学，如合成过滤器、海绵和织物，或土壤、砂岩和生物膜。该项目将检验的研究假设是，可以设计不同液体对在微/纳米结构表面上的润湿/去湿动力学(润湿滞后)的显著不对称性，并将其控制到工程毛细“二极管”，以有效地分离不相容的液体。检验这一假设的PI方法是使用表面纳米/微结构来控制动态滞后效应，该效应将导致快速或缓慢(阻止)润湿，这取决于润湿线的运动方向和液体的物理化学性质(例如，粘度、密度、界面张力)。该项目的中心目标是产生所需的基础知识，以了解和控制不同液体对在纳米/微结构介质上的自发和强制吸/排动力学，如合成过滤器、海绵和织物，或土壤、砂岩和生物膜。在理论发展和初步实验结果的基础上，该项目有两个具体的目标：(1)调节快湿和慢湿之间的交叉点；(2)控制慢(动力学)区的松弛速率。理论预测将指导实验参数和物理条件的选择，以实现两个特定的目标：(1)调节快湿和慢湿之间的交叉点；(2)控制慢(动力学)区的松弛速率。拟议的研究有可能对环境修复和水处理产生极大的变革。从研究生教育到K-12，学生和代表性不足的少数群体的参与非常广泛。

1605809Colosqui, CarlosThis project will examine an innovative approach for separation of water and oils, generally defined as organic compounds insoluble in water, by tuning the in wetting/de-wetting dynamics of drainage and absorption dynamics in engineered porous media. This project will advance the fundamental knowledge of (dynamic) wetting and liquid adhesion on "real" surfaces having complex nano- and microscale structure. The new knowledge will advance technologies for anti-fouling, drag reduction, and micro/nano-fluidic handling, having large impacts on the U.S. economy, infrastructure, and the environment.Recent theoretical developments by the PI indicate that the dynamics of the wetting process, present nontrivial regimes not described by conventional continuum-based and deterministic predictions. These theoretical predictions have been confirmed by molecular dynamics simulations and, more recently, through experimental work by the PI's group and other groups. Building upon these developments this project will examine the feasibility of exploiting novel phenomena such as the crossover from capillary-driven to thermally-activated wetting for innovative technical applications. The accomplishment of specific research objectives will be enabled by interdisciplinary and complementary skills of the PI and Co-PIs. To understand this will require incorporating the effects of thermal motion of the contact line which dominate the dynamics as mechanical equilibrium is approached. This project aims to generate fundamental knowledge required to understand and control the dynamics of spontaneous and forced imbibition or drainage in nano/microstructured media such as synthetic filters, sponges, and fabrics, or soil, sandstone, and biological membranes. The research hypothesis this project will examine is that significant asymmetries in wetting/de-wetting dynamics (wetting hysteresis) of different liquid pairs on micro/nanostructured surfaces can be designed and controlled to engineered capillary "diodes" for efficient separation of immiscible liquids. The PIs approach to test this hypothesis is to use the surface nano/microstructure to control dynamic hysteresis effects that will lead to fast or slow (arrested) wetting depending on the direction of motion of the wetting line and physicochemical properties of the liquids (e.g., viscosity, density, interfacial tensions). The central objective of this project is to generate fundamental knowledge required to understand and control the dynamics of spontaneous and forced imbibition/drainage by different liquid pairs on nano/micro-structured media such as synthetic filters, sponges, and fabrics, or soil, sandstone, and biological membranes. Building upon theoretical developments and preliminary experimental results the project has two specific objectives: (1) Tuning the crossover points between fast and slow wetting regimes; (2) Controlling the relaxation rate in the slow (kinetic) regime. Theoretical predictions will guide the selection of experimental parameters and physical conditions to accomplish two specific objectives: (1) Tuning the crossover point between fast and slow wetting regimes; and, (2) Controlling the relaxation rate in the slow (kinetic) regime. The proposed research has the potential to be highly transformative to environmental remediation and water treatment. The engagement of students and underrepresented minorities is extensive from graduate education to K-12.