High-energy storage graphene oxide modified phase change microcapsules from regenerated chitin Pickering Emulsion for photothermal conversion

Abstract Microencapsulated phase change materials (microPCMs) are not only important thermal energy storage medium but can also be applied in harvesting and storage of solar thermal energy by using solar absorbent materials as the shell. In this study, high energy storage polyurea (PUA) microPCMs for photothermal storage were fabricated from a Pickering emulsion consisting of bio-derived and sustainable regenerated chitin (RCh) from shrimp shells as the emulsifier. Graphene oxide (GO) was used as the photon captor and paraffin wax as the phase change material (PCM). The chemical, physical and thermal properties of the resulting microPCMs were studied. Using 0.1% w/w RCh Pickering emulsifier and 0.1% w/w GO to modify the microPCM, a 92.3% encapsulation efficiency was achieved. The microPCM at a core/shell ratio of 9:1 stored up to 234.7 J/g heat energy, was leak proof, and thermally reliable over 100 heating and cooling cycles with efficient photothermal conversion up to 76.03% conversion efficiency. Therefore, this cost-effective green process can be embraced for fabrication of high-energy storage and reliable functional microPCMs.