Facile synthesis of microencapsulated 1-dodecanol/melamine-formaldehyde phase change material using in-situ polymerization for thermal energy storage

Abstract

In this study, a new microencapsulated organic PCM (MicroPCM) was developed and its thermal energy storage (TES) properties were experimentally investigated. The microcapsules were prepared through a facile in-situ polymerization process using 1-dodecanol as the core PCM and the melamine-formaldehyde as the shell material. The microstructural analysis results infer that, the as-prepared microcapsules were spherical in shape, and the existence of carbon, oxygen and nitrogen elements have confirmed the effective formation of the MicroPCM. The average particle size (490.2 nm), surface roughness and with no chemical interaction between the core and the shell materials have paved way for achieving improved storage stability of the MicroPCM. The microcapsules with high thermal storage capability of 91.2 % have exhibited good latent heat of fusion of 79.45 kJ/kg. The microcapsules were thermally stable up to 132.82 °C, which was substantially higher than that of the operating temperature range of the pure PCM. The measured thermal conductivity of the MicroPCM was relatively lower (0.1727 W/m K) which has satisfied the thermal insulation criteria as well. The thermal cycling test conducted for microcapsules showed excellent thermal reliability (reliability index of 94.4 %). Also, no chemical interaction was observed between the core and the shell materials even after 200 heating/cooling process. Based on the test results, it is inferred that, the MicroPCM with enhanced properties can be a promising candidate for low temperature thermal energy storage.