Robust, Low-Cost, Microencapsulated Phase Change Materials (RMPCMs)

"The use of novel, Microencapsulated Phase Change Materials (MPCMs) in solid form within heating and cooling systems offers the potential for reducing initial system construction costs and increasing efficiency. Previous attempts to use MPCMs have faileddue to rupture of the capsules during freeze/thaw cycles and shear generated by turbulent pumping. In this Phase I program, we successfully developed a new class of robust MPCMs, called RMPCMs, that contained hydrophilic surfaces with low sliding frictionand drag, producing low viscosity thermal exchange slurries. The RMPCMs contained PCM loadings >80 weight percent, exhibited near neutral buoyancy and resisted fracture during 500 hr of continuous testing within a chiller test loop. In Phase II, we willrefine the RMPCM material and manufacturing process, scale up to 50 lb quantities and conduct long-term testing in an industrial chiller system. Molecular modeling will be applied to identify the best eutectic PCM blends for use in the refined RMPCM. Ourteam includes resident experts in microencapsulation and heat exchanger technology, an MPCM manufacturer, a thermal exchange fluid supplier and U.S. Army Natick Labs, which will use the MPCMs in microclimate cooling applications. (P-020497)"