CAREER: Condensation-Driven Phase-Transitioning Surfaces

职业：凝聚驱动相变表面

• 批准号: 1847627
• 负责人: Sushant Anand
• 金额: $ 52.96万
• 依托单位: University of Illinois at Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1847627&HistoricalAwards=false
• 关键词: CAREER; Condensation; Driven; Phase; Transitioning

Condensation plays a pivotal role in countless natural and industrial activities, such as in cloud formation, electronic cooling, power generation, emulsion formation, water harvesting, and materials development. Promotion dropwise condensation on surfaces (instead of a liquid film) can result in significant savings in energy and cost in many applications like those mentioned above. In recent years, hydrophobic, superhydrophobic and liquid infused surfaces have been tested to promote dropwise condensation. However, the performance of such surfaces can get compromised easily by a variety of debilitating mechanisms such as random droplet nucleation within textures (leading to eventual film formation), surface flooding at high humidity, organic contamination, and surface degradation. The goal of this CAREER project is to understand condensation on a class of existing materials that can undergo phase-transition due to condensation itself. Such materials possess several beneficial attributes of solid and liquid surfaces that could be the key to overcome many of the challenges faced by the existing superhydrophobic or liquid infused surfaces. Investigation of condensation on such materials could also clarify the long-standing questions on the fundamentals surrounding phase-change, such as the role of substrate thermal conductivity, condensation rate and relative humidity on the growth of droplets and heat-transfer rates. Results from this research will be integrated with educational activities that seek to increase women/underrepresented-minority student participation in engineering via undergraduate (UG) student recruitment for water harvesting via condensation, and engagement with high-school (HS) students through university outreach program (UIC-CHANCE).The scientific objectives of this CAREER project is to discover new fundamental knowledge to inform development of coatings for condensation applications based on surfaces that undergo phase-transitions during condensation. This goal will be accomplished by performing comprehensive studies to understand water droplet interactions with phase-transitioning surfaces in absence/presence of condensation to determine the relation between nanoscale transport phenomena (e.g. temperature distribution below/around droplets) and the resulting macroscopic effects (reduced droplet adhesion, delayed droplet freezing on highly subcooled substrate (0 oC)) as a function of phase-transition material properties (such as their solid-state surface structure, water miscibility, thermal properties), thermodynamic conditions (the degree of subcooling and relative humidity) and interfacial properties using conventional (optical/IR microscopy) & advanced diagnostic tools (Environmental Scanning Electron Microscopy, X-Ray Phase Contrast Microscopy). As part of such investigations, a new methodology will be developed to measure temperature distribution in the condensing surface beneath droplets with nanoscale spatial resolution. The correlations established from experimental measurements and theoretical models will be supplemented with numerical simulations to elucidate the fundamentals of condensation on the special phase-transitioning surfaces.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.

凝结在无数的自然和工业活动中发挥着关键作用，例如云的形成、电子冷却、发电、乳化液的形成、水的收集和材料的开发。在许多应用中，如上面提到的，在表面（而不是液体膜）上滴状冷凝可以显著节省能源和成本。近年来，对疏水、超疏水和液体注入表面进行了促进滴状冷凝的试验。然而，这种表面的性能很容易受到各种削弱机制的影响，如纹理内的随机液滴成核（导致最终的薄膜形成）、高湿度下的表面泛洪、有机污染和表面降解。这个CAREER项目的目标是了解一类现有材料的冷凝，这些材料可以由于冷凝本身而经历相变。这种材料具有固体和液体表面的一些有益特性，这可能是克服现有超疏水或液体注入表面所面临的许多挑战的关键。研究这些材料上的冷凝也可以澄清长期存在的关于相变基本原理的问题，例如衬底导热系数、冷凝速率和相对湿度对液滴生长和传热速率的作用。这项研究的结果将与教育活动相结合，旨在通过本科（UG）学生招募冷凝集水的方式增加女性/少数族裔学生对工程的参与，并通过大学外展计划（UIC-CHANCE）与高中（HS）学生的接触。这个CAREER项目的科学目标是发现新的基础知识，为基于冷凝过程中发生相变的表面的冷凝应用涂层的开发提供信息。这一目标将通过进行全面的研究来实现，以了解在没有/存在冷凝的情况下水滴与相变表面的相互作用，以确定纳米级传输现象（例如水滴下方/周围的温度分布）与由此产生的宏观效应(减少液滴粘附，在高度过冷的基材（0℃）上延迟液滴冻结)作为相变材料特性（如它们的固态表面结构、水的混溶性、热特性）、热力学条件（过冷程度和相对湿度）以及使用传统（光学/红外显微镜）和先进诊断工具（环境扫描电子显微镜、x射线相衬显微镜）的界面特性的函数。作为此类研究的一部分，将开发一种新的方法，以纳米尺度的空间分辨率测量液滴下方冷凝表面的温度分布。通过实验测量和理论模型建立的相关性将辅以数值模拟来阐明在特殊相变表面上凝结的基本原理。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Adhesion of impure ice on surfaces

不纯的冰粘附在表面上

• DOI: 10.1039/d3mh01440a
• 发表时间: 2024
• 期刊: Materials Horizons
• 影响因子: 13.3
• 作者: Chatterjee, Rukmava;Thanjukutty, Rajith Unnikrishnan;Carducci, Christopher;Neogi, Arnab;Chakraborty, Suman;Bapu, Vijay Prithiv;Banik, Suvo;Sankaranarayanan, Subramanian K.;Anand, Sushant
• 通讯作者: Anand, Sushant

How to Select Phase Change Materials for Tuning Condensation and Frosting?

• DOI: 10.1002/adfm.202206301
• 发表时间: 2022-11
• 期刊: Advanced Functional Materials
• 影响因子: 19
• 作者: Rukmava Chatterjee;Umesh V. Chaudhari;S. Anand