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

这个i-Corps项目的更广泛的影响/商业潜力是开发用于温度管理和能源效率的微胶囊相变建筑材料。住宅和商业建筑约占美国总用电量的75%，导致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，使美国的能效提高高达20%。这种能源消耗的减少每年可以节省820亿美元。此外，建议的技术可用于多种建筑材料，包括墙板(例如，石膏板、石膏板、隔音板和阻燃板)、机械抹灰、天花板产品、地板产品、干砂浆、水泥混合物以及内外涂层。该i-Corps项目基于开发使用空心微珠的相变材料(PCM)微胶囊技术，以提高建筑材料的能效。在现有技术中，相变材料是通过在相变材料液滴表面合成一层聚合物壳来实现微胶囊的。这种类型的外壳价格昂贵，刚度/强度有限，热稳定性和化学稳定性低，易燃性高，导热系数低。这项拟议的技术通过使用尖晶石作为外壳材料来解决这些问题。空心微珠是燃煤发电厂产生的中空飞灰颗粒。空心微珠天生就有细小的毛孔，这些毛孔被一层薄的玻璃晶状薄膜密封。通过化学蚀刻去除这一膜，可以暴露毛孔，为相变材料进入空心微球的内部空隙提供了一条路径。一旦填充，然后在浸渍了PCM的空心微珠上涂上一层薄涂层，以防止可能的液体PCM泄漏。与现有产品相比，建议的PCM微胶囊已被证明成本更低、更坚固、更耐用、阻燃和导热系数更高。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.