I-Corps: Microencapsulation of phase change materials using cenospheres for thermal energy efficiency in building materials

I-Corps项目更广泛的影响/商业潜力是开发用于温度管理和能源效率的微封装相变建筑材料。住宅和商业建筑约占美国所有用电量的75%，到2020年，其能源成本总计将超过4100亿美元。拟议的微胶囊技术可以集成到建筑材料中，从而将美国的能源效率提高20%。这种能源使用的减少每年可节省820亿美元。此外，所建议的技术可用于广泛的建筑材料，包括墙板（例如，干墙、石膏板、隔音板和防火板）、机器应用的膏药、天花板产品、地板产品、干砂浆、水泥混合物以及内外涂料。I-Corps项目的基础是利用微球开发相变材料（PCMs）的微胶囊技术，以提高建筑材料的能源效率。在现有技术中，通过在PCM液滴表面合成聚合物外壳来实现PCM的微封装。这种类型的外壳价格昂贵，具有有限的刚度/强度，低热稳定性和化学稳定性，高可燃性和低导热性。提出的技术通过使用人类作为外壳材料来解决这些问题。微球是燃煤电厂产生的空心飞灰颗粒。微球本身就有小的孔，这些孔被一层薄薄的玻璃晶体薄膜密封。通过化学蚀刻去除该薄膜，可以暴露孔隙，为PCMs进入空心球体的内部空隙提供了途径。一旦填充，一层薄薄的涂层就会被涂在浸透了pcm的微球上，以防止液态pcm的泄漏。与现有产品相比，所提出的PCM微胶囊具有成本更低、强度更强、更耐用、耐燃和导热性更高的特点。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。

The broader impact/commercial potential of this I-Corps project is the development of microencapsulated phase change building materials for temperature management and energy efficiency. Residential and commercial buildings account for about 75% of all electricity use in the US and result in an energy costs that totaled over $410 billion in 2020. The proposed microcapsule technology may be integrated into building materials to improve US energy efficiency up to 20%. This reduction in energy use could lead to $82B savings per year. In addition, the proposed technology may be used in a broad array of building materials including wallboards (e.g., drywall, gypsum boards, acoustical panels, and fire-retardant panels), machine applied plasters, ceiling products, flooring products, dry mortar, cement mixtures, and interior and exterior coatings.This I-Corps project is based on the development of a microencapsulation technology for phase change materials (PCMs) using cenospheres to improve energy efficiency in building materials. In existing technologies, PCMs are microencapsulated by synthesizing a polymer shell on the surface of PCM droplets. This type of shell is expensive and has limited stiffness/strength, low thermal and chemical stability, high flammability, and low thermal conductivity. The proposed technology addresses these problems by using cenopheres as the shell material. Cenospheres are hollow fly ash particles generated in coal burning power plants. Cenospheres inherently have small pores that are sealed by a thin glass-crystalline film. By removing this film through chemical etching, the pores may be exposed, providing a path for PCMs to enter the internal void of the cenosphere. Once filled, a thin coating is then applied on the PCM-impregnated cenospheres to prevent the possible leaking of liquid PCMs. Compared with existing products, the proposed PCM microcapsules have been shown to be lower cost, stronger, more durable, flame resistant, and higher in thermal conductivity.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.