Fabrication of thermal energy storage wood based on graphene aerogel encapsulated polyethylene glycol as phase change material

Abstract

Thermal energy storage wood (TESW) was fabricated by using graphene aerogel encapsulated polyethylene glycol (PEG) as phase change material and wood as the matrix. The microstructure of TESW was investigated by scanning electron microscope (SEM), the thermal properties of TESW was determined by differential scanning calorimetry (DSC), thermal gravimetric analysis (TG) and laser flash diffusivity apparatus (LFA). The results showed that: (1) graphene aerogel (GA) encapsulated PEG composite was founded in the lumens of wood, there was no apparent interface between PEG and graphene aerogel; (2) the melting and freezing enthalpy of TESW were 11.81 and 27.91 J g-1, respectively. The melting and freezing point were 20 °C and 15 °C, respectively, which were suitable for human comfortable temperature; (3) incorporation of graphene aerogel improved the thermal conductivity of TESW apparently. Thermal conductivity of TESW was 0.374 W (m∗K)-1, which increased about 274% compared to pure wood; (4) TG and hygroscopicity test indicated that the TESW had excellent thermal and dimensional stability. The TESW was suggested as energy conservation building material for indoor temperature regulating due to its comfortable phase change temperature and prior latent heat.