Molecular-Scale Solutal Electrokinetics and Micro-Scale Control of Interfacial Phenomena in Ebullient Heat Transfer

沸腾传热中界面现象的分子尺度溶液动电学和微尺度控制

• 批准号: 0755720
• 负责人: Raj Manglik
• 金额: $ 30万
• 依托单位: University of Cincinnati Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2013-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0755720&HistoricalAwards=false
• 关键词: Molecular; Scale; Solutal; Electrokinetics; Micro

CBET-0755720, ManglikThis research is a fundamental multi-scale study of the molecular electrokinetics of surface-active agents (organic/synthetic monomers, micelles and/or biomolecules), and their modulation of interfacial phenomena (surface wetting and interfacial tension) for the control of nucleate boiling and associated ebullience in aqueous solutions. At the molecular-scale, the additive molecular dynamics at the liquid-vapor interface, and its physisorption and electrokinetics at the liquid-solid interface are to be investigated. These processes in turn affect micro-scale changes in liquid-vapor interfacial tension and solid-liquid wetting (where the two usually complimentary forces can now be decoupled due to the reagent electrokinetics and molecular mobility). The consequent changes in transient transport mechanisms during pool boiling with its characteristic embryonic vapor nucleation and subsequent bubble growth will be investigated. Also, the macro-scale ebullient heat transport, governed by macro-layer interfacial heat transfer, bubble growth and its dynamics (coalescence, collapse, and translation) will be studied and modeled, so as to identify and correlate boiling control (enhancement or suppression) parameters. In essence, the principal hypothesis that liquid-vapor interfacial tension and solid-liquid surface wetting (primary determinants of micro-scale nucleation and macro-scale ebullience, and hence boiling control predictors) can be decoupled and controlled by the molecular adsorption-physisorption, micellar dynamics, and electrokinetics of reagents in aqueous solutions would be established, and predictive correlations developed. Intellectual Merit: The findings of this study will (i) advance the fundamental science of interfacial phenomena and its manipulation by the molecular dynamics of surface-active agents in aqueous solutions, (ii) be insightful in establishing the micro-scale mechanisms at liquid-solid and liquid-vapor interfaces that characterize nucleate phase-change, and (iii) lead to the advancement of the fundamental science and engineering for an effective passive control technique, using ?designed? reagents (nano-sized micelle-chains and surfactant-like protein-based biomolecules), for nucleate phase-change ebullience and heat transfer. Broader Impact: This project will significantly enhance the training of students in cross-stream and inter-disciplinary engineering science, provide an experience in advanced experimentation (state-of-the-art instrumentation) and mathematical/simulation analysis, and help produce highly motivated engineers and researchers who have the depth and breadth of knowledge, and skills for advanced research and education careers. The integration of research with education, particularly involving women and minority engineering students, would further address the national need of training a more diverse engineering work force. Also, outreach with industrial and national laboratory partners will lend to long-term technology transfer. In a broader transformative essence, the reagent molecular dynamics/electrokinetics-modulated ebullient phase-change discovered in this work, is a new frontier in developing not only novel chemical and biological sensors, micro-fluidic or lab-on-chip devices, micro-scale heat exchangers, and effective thermal management of space-based systems, but also novel surface-active biomolecules and micellar polymers that may have a wider range of inter-disciplinary applications.

CBET-0755720，Manglik 这项研究是对表面活性剂（有机/合成单体、胶束和/或生物分子）的分子电动学及其对界面现象（表面润湿和界面张力）的调节的基础性多尺度研究，用于控制水溶液中的核沸腾和相关的沸腾。 在分子尺度上，研究液-汽界面的加性分子动力学及其在液-固界面的物理吸附和动电动力学。 这些过程反过来影响液-汽界面张力和固-液润湿的微观变化（由于试剂电动学和分子迁移率，这两种通常互补的力现在可以解耦）。将研究池沸腾期间瞬态传输机制的后续变化及其特征性的胚胎蒸汽成核和随后的气泡生长。 此外，还将研究和模拟由宏观层界面传热、气泡生长及其动力学（聚结、崩溃和平移）控制的宏观沸腾热传输，以便识别和关联沸腾控制（增强或抑制）参数。 本质上，液-汽界面张力和固-液表面润湿（微观尺度成核和宏观沸腾的主要决定因素，因此沸腾控制预测因子）可以通过水溶液中试剂的分子吸附-物理吸附、胶束动力学和电动动力学解耦和控制的主要假设将被建立，并且预测 相关性得到发展。 智力价值：这项研究的结果将（i）推进界面现象的基础科学及其通过水溶液中表面活性剂的分子动力学的操纵，（ii）在建立表征成核相变的液-固和液-汽界面的微观机制方面具有洞察力，（iii）导致基础科学和技术的进步 使用“设计”来设计有效的被动控制技术。用于核相变沸腾和传热的试剂（纳米胶束链和类似表面活性剂的蛋白质生物分子）。 更广泛的影响：该项目将显着加强对学生在跨学科和跨学科工程科学方面的培训，提供高级实验（最先进的仪器）和数学/模拟分析的经验，并帮助培养具有进取心的工程师和研究人员，他们拥有深度和广度的知识以及高级研究和教育职业的技能。 研究与教育的结合，特别是让女性和少数族裔工程专业学生参与进来，将进一步满足国家培养更加多样化的工程劳动力的需求。此外，与工业和国家实验室合作伙伴的联系将有助于长期技术转让。 从更广泛的变革本质来看，这项工作中发现的试剂分子动力学/动电学调制的沸腾相变不仅是开发新型化学和生物传感器、微流体或芯片实验室设备、微型换热器和天基系统的有效热管理的新领域，而且是开发新型表面活性生物分子和胶束聚合物的新领域，它们可能具有 更广泛的跨学科应用。