Phase change materials based on comb-like polynorbornenes and octadecylamine-functionalized graphene oxide nanosheets for thermal energy storage

Abstract

Organic phase change materials (PCMs) have been proved as one of the most promising materials for alleviating the energy crisis and environmental pollution. However, the “leakage” of PCMs during the phase change process has hampered their advanced applications in thermal energy storage. Here, we deliver a novel shape-stabilization strategy to fabricate a series of new form-stable PCMs (FSPCMs) by employing comb-like polynorbornenes along with the octadecylamine-functionalized graphene oxide (C18-rGO) nanosheets as the supporting networks and paraffin as the latent heat material. The graphene oxide (GO) nanosheets crosslinked by long-chain carbon alkyl group prevented the graphene derivate materials from forming the serious issue of agglomeration, and endowed excellent structural stability to the composite FSPCMs. Meanwhile, the toughness of the composites was further improved with the addition of the comb-like polynorbornenes. Paraffin was tightly imprisoned in the frameworks formed by the C18-rGO nanosheets and comb-like polynorbornenes, resulting in no leakage even above their phase change temperature. The multiple thermal cycling tests proved that these FSPCMs had excellent thermal cycling reliability. In particular, they were also capable of absorbing or releasing thermal energy at a high rate, offering a significant potential to be used as the effective thermal management materials in electronic devices or solar energy storage systems. Notably, comb-like polynorbornenes demonstrated to be capable of being employed as the supporting networks of paraffin, opening a new door for fabricating novel types of FSPCMs as well as broadening the practical application of the comb-like polymers.