PMMA nano-encapsulated phase change material colloids for heat management applications

Phase Change Materials (PCM) emulsions or micro-nano-encapsulated into organic and inorganic shells have attracted scientific interest for their potential to enhance the thermal capacity and the efficiency of heat transfer liquids. In this work, RT21HC, a commercial PCM with transition temperature at 21 degrees C, has been successfully nano-encapsulated into Poly(methyl-methacrylate) (PMMA) shells by an emulsion polymerization process after the selection of proper surfactant and synthesis parameters, in order to obtain complete encapsulation and stable colloidal dispersions. Water-based colloidal dispersions con-taining 10 wt% PCM were obtained and characterized from point of view of microstructure, colloidal sta-bility, rheological properties, apparent heat capacity and thermal diffusivity, in order to show the potential of these colloidal dispersions as advanced heat management fluids. With the aim to mitigate the phenomenon of PCM crystallization supercooling that is caused by nano-confinement and is cause of apparent thermal capacity loss, the effect of incorporation into the nano-capsules of two fatty esters, two fatty alcohols and a fatty acid as nucleating agents, has also been studied. (c) 2023 Elsevier B.V. All rights reserved.