Nano-Scale Physics of Icephobicity and Path Toward Durable Icephobic Surfaces

防冰表面通过影响包括基础设施、交通网络和发电系统在内的广泛系统，在寒冷气候下的人类日常生活中发挥着至关重要的作用。输电系统中的结冰可能导致电线杆和铁塔倒塌以及导线断裂。飞机结冰会导致阻力增加，并可能导致升力损失和潜在的灾难性事件。能源系统中的结冰显著降低了传热速率，导致这些系统的低效运行。根据劳伦斯伯克利国家实验室的数据，冰暴占美国输电中断的10%。工业的财政损失估计每年为30亿至50亿美元。除了经济损失外，每年冬天美国约有300万人还遭受冰风暴造成的电力损失。尽管在社会中起着至关重要的作用，但为这种要求苛刻的应用开发高性能防冰表面仍然难以实现。 这项研究将涉及实验和理论，以揭示长度尺度，几何形状和界面曲率对冰形成的作用，并将开发新的工具来解决结冰。非润湿，液体注入和水合表面启发了防冰表面的发展路线。然而，高冻结温度、高冰粘附强度（~50 - 100 kPa）和随后的积冰、低机械耐久性和高生产成本限制了它们的实际应用。该研究计划的目标是阐明冰形成和表面粘附的基本纳米级物理学，其中涉及固体-冰界面的热力学，传热和力学研究。这些物理学为抑制冰的形成和最小化冰在表面上的粘附提供了基本途径。我们建议在纳米尺度上突破憎冰性的极限。通过使用环境扫描电子显微镜和受限纳米通道在纳米尺度上研究冰的成核和生长，我们将探索冰的疏水性极限。提出了一种新的冰粘附预测数学模型，为实现高耐久性的极低冰粘附沿着提供了基本途径。研究人员将研究这种预测模型，并随后开发和表征一类新的疏冰材料，称为3D纳米粘弹性材料。这些防冰材料将通过各种抗冰性和耐久性指标进行检查。该研究计划的教育任务将提供一个平台，以发现来自代表性不足群体的学生的才能，并为他们提供未来多学科工作环境所需的微/纳米工程技能。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Anti-icing surfaces play a critical role in human daily lives in cold climates by impacting a broad range of systems including infrastructure, transportation networks, and power generation systems. Icing in electricity transmission systems can lead to collapse of poles and towers and rupture of conductors. Icing in aircrafts results in increased drag and may lead to loss of lift force and potential catastrophic events. Icing in energy systems significantly drops the heat transfer rate leading to inefficient operation of these systems. According to the Lawrence Berkeley National Laboratory, ice storms account for 10% of power transmission outages in the United States. The financial loss for industries is estimated at $3-5 billion annually. In addition to financial losses, around 3 million people in the US suffer from power losses caused by ice storms every winter. Despite the vital role in society, the development of high-performance anti-icing surfaces for such demanding applications remains elusive. This research will involve experiments and theory to reveal the role of length scale, geometry, and interfacial curvature on ice formation, and will develop new tools to address icing.Non-wetting, liquid-infused and hydrated surfaces have inspired routes for development of anti-icing surfaces. However, high freezing temperature, high ice adhesion strength (~50-100 kPa) and subsequent ice accretion, low mechanical durability, and high production cost have restricted their practical applications. The goal of this research program is to elucidate the underlying nano-scale physics of ice formation and adhesion on surfaces which involves studies of thermodynamics, heat transfer and mechanics of solid-ice interfaces. These physics provide fundamental routes for suppression of ice formation and minimization of ice adhesion on surfaces. We propose to break the limit of icephobicity at the nano-scale. Through studies of ice nucleation and growth at the nano-scale using Environmental Scanning Electron Microscopy and confined nano-channels, we will explore the icephobicity limits. A new predictive mathematical model on ice adhesion is proposed that provides fundamental routes to achieve extremely low ice adhesion along with high durability. Investigators will examine this predictive model and subsequently develop and characterize a new class of icephobic materials called 3D nano-viscoelastic materials. These anti-icing materials will be examined through various icephobicity and durability metrics. The educational tasks in this research program will provide a platform to discover the talents of students from underrepresented groups and to equip them with micro/nano engineering skills required for future multidisciplinary work environments.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.