EAGER: A bio-inspired approach for enhancing lifetime of salts during icing and frost formation

#1644815Anand， susshan研究化学增强盐颗粒，延长其使用寿命以防止结冰和霜冻道路上的结冰会产生深远的影响，包括车祸、交通拥堵和数十亿美元的经济生产力损失。迄今为止，世界上最可行的解决方案是在道路上使用除冰盐，通过降低冰点来抑制冰的形成。然而，它们的使用也对我们的环境和经济构成了重大威胁。仅在美国，近43%的盐使用量与高速公路除冰有关（耗资约22亿美元）。除冰盐增加了道路附近的土壤盐分，造成更高的碱度，增加了水分潴留和土壤肥力的损失，从而对植物生长产生不利影响。盐也可以通过土壤渗透，最终到达湖泊和地下水系统，在那里，盐度的增加会对植物群、水生/两栖动物和我们自己的饮用水供应造成严重的有害影响。此外，除冰盐对我们的基础设施有严重的影响，它会促进钢材（例如桥梁、车辆）的腐蚀或混凝土的分解。本研究提出，可以通过添加特殊的环保化学物质来提高盐的使用寿命，这些化学物质可以降低盐的溶解速度，同时保持盐的除冰功能。这些研究还将导致对存在吸湿性物质（如盐）时水到冰的相变基本原理的新理解的发展。这项工作将导致一种新型除冰盐的开发，与传统盐相比，这种盐的使用寿命要长得多，有利于运输安全和环境的可持续性。盐颗粒可以通过两种机制抑制冰的形成：一种是降低水的冰点，另一种是通过充当“湿度汇”来降低其附近的蒸气过饱和度。将制备化学增强的盐颗粒，这些盐颗粒可以保持其吸湿性，但也可以在溶解过程中减缓盐分子在环境中的水蛭作用。实验将进行：(a)制造化学强化盐颗粒，并研究制备此类材料的可扩展技术；(b)研究在不同热力学条件下（湿度水平、过冷程度），通过使用化学强化盐颗粒与普通盐颗粒相比，研究除冰延迟；(c)研究盐浸出率作为化学性质和热力学条件的函数。这些任务将通过热成像和光学技术的结合来完成，同时在化学增强盐颗粒上进行冰形成的现场观测。除了开发一种具有延长寿命的新型除冰盐颗粒外，拟议的研究还有可能为在盐等吸湿性化学物质存在下的冰形成提供新的线索。

#1644815Anand, SushantInvestigating chemically enhanced salt particles with extended lifetime for ice and frost preventionIce formation on roads can have profound effects, including car accidents, traffic congestion, and billions of dollar losses in economic productivity. To date, the most viable solution worldwide is to use deicing salts on roads that suppress ice formation through freezing point depression. However, their usage also poses significant threats to our environment and economy. Nearly 43% of salt usage related to deicing highways (costing around $2.2 billion) in USA alone. Deicing salts increase the soil salinity near roads causing higher alkanity, increased moisture retention and loss of soil fertility, thus adversely affecting plant growth. The salt can also percolate through soil, ultimately reaching lakes and underground water systems where the increase in salinity can lead to significantly harmful effects on flora, aquatic/amphibious animals and our own drinking water supplies. Furthermore, deicing salts have serious consequences for our infrastructure by promoting corrosion of steel (e.g. in bridges, vehicles) or disintegration of concrete. This study proposes that the lifetime of salt can be increased by enhancing them with special environmentally friendly chemicals that can decrease the dissolution rate of salts while maintaining their deicing functionality. These studies will also lead to development of new understanding of the fundamentals of phase change of water to ice in the presence of a hygroscopic material (such as salt). The work will lead to development of a new class of deicing salts that will have significantly large lifetime compared to conventional salt and will be beneficial for both transportation safety and environmental sustainability.A salt particle can suppress ice formation due to two mechanisms - by depressing the freezing point of water, and by depressing the vapor supersaturation in its vicinity by acting as a "humidity sink". Chemically enhanced salt particles that may maintain their hygroscopic properties but also slow the leeching of salt molecules in the environment during dissolution will be prepared. Experiments will be performed to: (a) to fabricate chemically enhanced salt particles, and investigate scalable techniques for preparing such materials, (b) investigate the deicing delays through use of chemically enhanced salt particles compared to plain salt particles at different thermodynamic conditions (humidity levels, degree of subcooling), (c) investigate the salt leeching rate as a function of chemical properties and thermodynamic conditions. These tasks will be accomplished using combination of thermographic and optical techniques during in-situ observation of ice formation on the chemically enhanced salt particles. In addition to the development of a new type of deicing salt particles with enhanced lifetime, the proposed studies have the potential to shed new light on ice formation in presence of hygroscopic chemicals such as salts.