PEG/SiO2–Al2O3 hybrid form-stable phase change materials with enhanced thermal conductivity

•The PEG/SiO2–Al2O3 hybrid form-stable phase change material (PCM) was obtained through the sol–gel method.•The inexpensive aluminum nitrate and tetraethyl orthosilicate were used as sol precursors.•This organic–inorganic hybrid process can effectively enhance the thermal conductivity of PCMs.•The PCM exhibited high thermal stability and excellent form-stable effects.

The thermal conductivity of form-stable PEG/SiO2 phase change material (PCM) was enhanced by in situ doping of Al2O3 using an ultrasound-assisted sol–gel method. Fourier transform infrared spectroscopy (FT-IR) was used to characterize the structure, and the crystal performance was characterized by the X-ray diffraction (XRD). Differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA) were used to determine the thermal properties. The phase change enthalpy of PEG/SiO2–Al2O3 reached 124 J g−1, and thermal conductivity improved by 12.8% for 3.3 wt% Al2O3 in the PCM compared with PEG/SiO2. The hybrid PCM has excellent thermal stability and form-stable effects.