Optimized emulsifier combination based microencapsulated phase change materials (MicroPCMs): Preparation, characterization, and applications

Microencapsulated phase change materials (microPCMs) using urea-formaldehyde as the shell material and tetradecane as the phase change material were successfully prepared via in situ polymerization reaction in an oil-in-water emulsion. Four groups of emulsifiers containing ionic or nonionic kinds were investigated through the performance of the as-prepared microPCMs including micro-topography, thermal energy storage, and thermal stability. The emulsifying capacity and the underlying mechanism of the emulsifiers were also evaluated and discussed. Experimental results showed that the combined emulsifier group of Triton X-100/sodium dodecyl benzene sulfonate as the emulsifier provided the optimal emulsification for the preparation of microPCMs. The as-prepared microPCMs were then combined with expanded polyurethane in two manners to fabric thermal insulation composites with the phase change energy storage (PES) function. The thermal insulation and PES properties of the functional composites were evaluated using a thermal imager and wireless thermocouple. Both the composites revealed a distinct temperature transition region in their temperature-time curves, which demonstrated that the PES functional composites had been successfully fabricated. The research results may provide reliable data support for practical applications of microPCMs in the PES functional composite field.