Graphene Functionalization of Polyrotaxane-Encapsulated PEG-Based PCMs: Fabrication and Applications.

Abstract

Phase change materials (PCMs) have received much attention regarding the thermal regulation of electronic devices. However, the main limitations of using organic PCMs are the low thermal conductivity and leakage during the phase change process. This work aims to improve these limitations to increase the thermal conductivity of the leakage-proof PCM formed by a polyrotaxane that serves as a support material to encapsulate PEG. For this purpose, different contents of graphene nanoplatelets (GNP) are blended. To facilitate its postindustrial production and to meet ecological standards, the synthesis of this PCM is simple and only using water as a solvent. The PCMs can be thermally processed conveniently by a hot press. Furthermore, the PCMs achieve high enthalpy values (132.9–142.9 J g−1) due to the action of GNPs as thermally conductive fillers. The PCMs exhibited an increase of 60–257% in thermal conductivity values with higher GNP content, and show great shape stability and no leakage during phase change. These improvements solve the main problems of organic PCMs, thus making PLR-PEG-GNP-based materials a good candidate for use as thermal energy storage materials in industrial applications as thermoregulators of solid-state disks or realizing the “shaving peaks and filling valleys” effect for thermoelectric generators.