Multi-scale Study of Coupled Reaction and Wetting in Droplet Spreading

液滴铺展中的耦合反应和润湿的多尺度研究

• 批准号: 1104835
• 负责人: Ying Sun
• 金额: $ 24万
• 依托单位: Drexel University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1104835&HistoricalAwards=false
• 关键词: Multi; scale; Study; Coupled; Reaction

TECHNICAL SUMMARYThis award supports theoretical and computational research and educational activities related to coupled reaction and wetting dynamics in droplet spreading. Special attention is paid to examine the effect of intermetallic compound formation on drop wetting kinetics, contact line advancement, and the evolution of the solid-liquid interface. Using a multi-scale model that integrates the hybrid phase-field and arbitrary Lagrangian-Eulerian approach at the macroscopic scale and molecular dynamics simulations at the atomistic level, this project seeks to address several fundamental issues in the understanding and prediction of reactive wetting: (i) What are the dominating driving forces and dissipation mechanisms in reactive wetting? The PI aims to understand whether the relevant driving forces and dissipation mechanisms can be separated into distinct regimes or whether they are strongly coupled in one or multiple regimes. Using inputs from molecular dynamics simulations, the PI will integrate the intermetallic compound formation and growth into the macroscopic moving boundary problem to examine the coupling mechanisms among flow, species transport, and chemical reaction.(ii) How is material delivered to the contact line during new interface formation? The PI will examine the effect of reaction and surface alloying on mechanisms that deliver new materials to the contact line region. The effects of intermetallic compound formation and growth in the contact line region on drop wetting kinetics will be quantified.(iii) How does the solid-liquid interface evolve during coupled reaction and wetting? The flow, temperature, and concentration fields will be computed to explain how they interact to result in a certain shape of the solid-liquid interface and types of intermetallic compounds. The PI will also quantify the intermetallic compound growth rate and relate it with the rate of substrate dissolution. The possibility of solid to liquid to solid phase transition will be explored and results will be compared with experimental observations from the literature.Fundamental understanding of coupled reaction and wetting dynamics during reactive wetting is crucial in creating stronger bonds in materials joining, better adhesion for thin film coating, novel composites for bio-implants, and new routes for surface modification with tunable functionalities. This work will have impact on areas ranging from materials processing, MEMS fabrication, electronics packaging, to energy conversion and storage and surface chemistry. This project will also advance a largely uncharted area of research that is concerned with multi-component, multi-phase systems with flow, heat/mass transfer, phase change, and chemical reactions. Graduate and undergraduate students will be trained working in an interdisciplinary research area at the intersection of physics, materials science, engineering, and chemistry. Collaborations with McMaster University and Sandia National Laboratories will enable the PI and her students to interact with leading research groups on performing atomistic modeling of phase transformation. The proposed research will also enable new course materials for two graduate-level courses and support undergraduate researchers via Drexel's Hess Honors program and the six-month intensive research co-op program. Outreach will extend to pre-college students and those from underrepresented groups through PI's mentoring of RET teachers and Girl Scouts of Eastern Pennsylvania from School District of Philadelphia.NONTECHNICAL SUMMARYThis award supports theoretical and computational research and educational activities related to how a droplet makes contact with a surface and spreads. The PI will also include the reaction of the liquid with the solid substrate on which it is spreading. This plays an important role in many technological applications including materials processing and joining, thin film coating, printable electronics fabrication, heterogeneous catalysis, droplet actuation and manipulation, and surface modification. Recent advances in materials that are structured down to a scale some ten thousand times smaller than a human hair require greater precision in the control of this reactive wetting processes. Despite its importance, reactive wetting remains a poorly understood process. The PI will perform computer simulations aimed to address fundamental issues in understanding reactive wetting and the ability to use computers to simulate the process. Model predictions will be validated against experimental observations. This project is important in materials processing and joining, thin film coating, and droplet manipulation processes. The process involves at least three interfaces that are typically away from the balanced state of equilibrium and plays a significant role in synthesis and processing of advanced materials for energy conversion and storage, bio-implants, micro-electro-mechanical devices, and electronics packaging. The complex multi-phase systems studied by the PI occur in numerous process industries, as well as in nature and in living organisms. Thus, this work will help to establish research methodology that can be used in a broad array of applications.The interdisciplinary nature of the project, at the intersection of physics, materials science, engineering, and chemistry, makes it a great educational opportunity for students. Graduate students and undergraduate students will be trained to utilize interdisciplinary tools in fluid dynamics, heat/mass transfer, and materials science to study transport phenomena in materials processing across length scales. The proposed research will also enable new course materials for two graduate-level courses. Research products will be disseminated in part through open-source computer code packages. The community outreach programs will extend to inner-city K-12 teachers and students in Philadelphia with approximately 80% minority students.

技术摘要这一奖项支持理论和计算研究和教育活动，与液滴扩散中的耦合反应和润湿动态有关。特别注意金属间化合物形成对滴润湿动力学的影响，接触线的进步以及固液界面的演变。使用一个多尺度模型，该模型以宏观量表和原子级的分子动力学模拟整合了混合相田间和任意的拉格朗日 - 欧拉尔式方法，该项目旨在解决反应式润湿的理解和预测时的几个基本问​​题：（i）（i）在反应式湿润机构中占主导地位的动力和灭绝机制？ PI旨在了解相关的驱动力和耗散机制是否可以分为不同的政权，或者它们是否在一个或多个制度中强烈耦合。使用分子动力学模拟的输入，PI将将金属间化合物形成和生长整合到宏观移动边界问题中，以检查流，物种传输和化学反应之间的耦合机制。（ii）在新界面形成期间如何将材料传递到接触线上？ PI将检查反应和表面合金对向接触线区域输送新材料的机制的影响。将量化金属间化合物形成和接触线区域的生长对滴润湿动力学的影响。（iii）在耦合反应和润湿过程中，固液界面如何演变？将计算流动，温度和浓度场，以解释它们如何相互作用以产生固定液体界面的某种形状和金属间化合物的类型。 PI还将量化金属间化合物生长速率，并将其与底物溶解速率相关联。将探索固体到液体到固体过渡的可能性，并将结果与​​文献的实验观察结果进行比较。对反应性润湿过程中耦合反应和润湿动态的理解对于在材料连接中创造更强的键，对薄膜涂料的更好粘附，对薄膜涂层的粘附，新颖的复合材料的粘合，用于表面和新的途径以及功能化的途径。这项工作将对从材料加工，MEMS制造，电子包装到能量转换和存储以及表面化学的区域产生影响。该项目还将推进一个在很大程度上未知的研究领域，该研究领域与具有流量，热/传质，相变和化学反应的多组分，多相系统有关。研究生和本科生将在物理，材料科学，工程和化学交集的跨学科研究领域接受培训。与麦克马斯特大学和桑迪亚国家实验室的合作将使PI和她的学生能够与领先的研究小组进行有关相变的原子建模的互动。拟议的研究还将通过Drexel's Hess Honors计划和六个月的密集研究合作计划为两项研究生级课程和支持本科研究人员提供新课程材料。外展活动将扩展到前大学的学生以及来自代表性不足的团体的学生，通过PI的指导，来自费城学区的宾夕法尼亚州东部的RET教师和女童子军。本技术摘要支持理论和计算研究和教育活动与与滴水的方式相关的理论和计算研究和教育活动。 PI还将包括液体与所在的固体基材的反应。这在许多技术应用中起着重要作用，包括材料加工和连接，薄膜涂料，可打印的电子制造，异质催化，液滴致动和操纵以及表面修饰。材料的最新进展低至比人的头发小约一千倍，在控制这种反应性润湿过程时需要更高的精度。尽管其重要性，但反应性润湿仍然是一个鲜为人知的过程。 PI将执行旨在解决理解反应性润湿以及使用计算机模拟过程的能力方面的基本问题的计算机模拟。模型预测将通过实验观察结果进行验证。该项目在材料处理和加入，薄膜涂料和液滴操纵过程中很重要。该过程涉及至少三个界面，这些接口通常远离平衡状态，并在高级材料的合成和加工中起着重要作用，用于能量转化和存储，生物植入物，微型机械设备以及电子包装。 PI研究的复杂多相系统发生在许多过程行业，自然界和生物体中。因此，这项工作将有助于建立可用于广泛应用程序的研究方法。项目的跨学科性质，物理，材料科学，工程和化学的交集使其成为学生的绝佳教育机会。研究生和本科生将接受培训，以利用跨学科的工具，用于流体动力学，热量/传播和材料科学，以研究跨长度尺度的材料处理中的运输现象。拟议的研究还将为两个研究生级课程提供新的课程材料。研究产品将通过开源计算机代码包进行部分传播。社区外展计划将扩展到市中心的K-12教师和费城的学生，约有80％的少数学生。