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

I-Corps项目的更广泛影响/商业潜力是开发用于温度管理和能源效率的微胶囊相变建筑材料。 住宅和商业建筑约占美国所有用电量的75%，到2020年，能源成本总计超过4100亿美元。 拟议中的微胶囊技术可能会被整合到建筑材料中，以提高美国的能源效率高达20%。 这种能源使用的减少每年可以节省820亿美元。 此外，所提出的技术可以用于包括墙板（例如，这一项目的基础是利用空心微珠开发相变材料的微胶囊技术，以提高建筑材料的能源效率。在现有技术中，通过在PCM液滴的表面上合成聚合物壳来微囊化PCM。这种类型的壳是昂贵的，并且具有有限的刚度/强度、低的热稳定性和化学稳定性、高的可燃性和低的导热性。所提出的技术通过使用空心球作为外壳材料来解决这些问题。 空心微珠是燃煤电厂产生的中空飞灰颗粒。空心微珠固有地具有由薄玻璃晶体膜密封的小孔。通过化学蚀刻去除该膜，可以暴露孔，为PCM进入空心微珠的内部空隙提供路径。一旦填充，然后在PCM浸渍的空心微珠上施加薄涂层以防止液体PCM的可能泄漏。与现有产品相比，拟议的PCM微胶囊已被证明成本更低，强度更高，更耐用，阻燃性更好，导热性更高。该奖项反映了NSF的法定使命，并已被认为是值得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的支持。

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.