Thermal conductivity enhanced SiO₂-Al₂O₃/PEG form-stable phase change material based on the sol-gel doping of aluminum isopropanol

The thermal conductivity enhanced SiO₂-Al₂O₃/PEG form-stable phase change composite was synthesized through the ultrasound assisted sol-gel method with aluminum isopropanol (AIP) and tetraethoxysilane as the sol precursor, and polyethylene glycol (PEG) as the phase change component. FTIR and XRD were used to characterize the structure and measure the crystallization properties of the SiO₂-Al₂O₃/PEG. The thermal performance and thermal stability were analyzed by DSC and TGA. The form-stable performance was fixed by microscopic heating stage and digital photo technology. The thermal conductivity of the SiO₂-Al₂O₃/PEG were measured by the thermal conductivity meter. The results show that the phase change enthalpy of the product reaches above 100 J/g, and the material has a good thermal stability within 300 ℃. When the mass ratio of Al to Si is 0.2:1, the thermal conductivity of the composite reaches 0.414 W/(m·K), which increases by 39.3%. Besides, it has an excellent form-stable performance.