Robust, Low-Cost, Microencapsulated Phase Change Materials

The use of novel Phase Change Materials (PCMs) in solid form within heating and cooling systems offers the potential for reducing initial system construction costs and increasing efficiency. Current PCMs cause problems such as fouling, segregation and highslurry viscosity within the heat exchanger system. Foster-Miller proposes to extend our successful microencapsulation technology to produce robust polymer microcapsules that contain high loadings of PCM selected for a specific temperature range. Therobust, microencapsulated PCMs (RMPCMs) will contain hydrophilic surfaces that exhibit low sliding friction and drag, producing RMPCM slurries with high fluidity. RMPCMs will exhibit near neutral buoyancy, high toughness to avoid fracture during long-termcycling and stability at operating temperature. Our economical microencapsulation process can be scaled-up to large quantities in conventional equipment. In Phase I, we will select one PCM with the appropriate transition temperature range and produce aseries of RMPCM test samples of varying size, shell thickness and PCM loading. RMPCM slurry fluidity, stability, thermal energy transfer efficiency and resistance to fracture during repeated cycling will be demonstrated within a test system. Our teamincludes experts in polymers, microencapsulation, thermal energy systems and slurry flow and a heat exchanger fluid manufacturer. (P-00885)The proposed robust, microencapsulated phase change materials will enable the design and construction of simpler,more efficient, lower-cost and more compact thermal energy systems than are now available. Commercial applications include central heating and cooling systems, chilled water systems for large buildings, and secondary loop refrigeration systems.