Preparation and characterization of high-temperature non-flowing SiO 2 /EG/paraffin composites by high-temperature refining

Abstract The novel SiO 2 /EG/paraffin composite phase change materials (PCMs) were prepared by high-temperature refining in order to provide sufficient energy to enable paraffin to be adequately thickened by nano-SiO 2 and EG. The results showed that paraffin was hold by nano-SiO 2 and porous EG successfully, and could maintain original shape with non-flowing under the condition of 200 °C. The dropping point of the PCMs-2 could reach 160 °C and the oil separation rate as low as 7.79% in 100 °C for 30 h, but PCMs-1 has only reached 70 °C and 68.4%, Which indicated that PCMs prepared by high-temperature refining had excellent colloid stability. DSC and TGA results showed that the PCMs exhibited excellent thermal stability. Furthermore, thermal conductivity of PCMs-3 was 0.739 W/(m K), which improved the thermal performance of paraffin(0.303 W/(m K)) significantly. High-temperature refining was applied to prepare high-temperature non-flowing PCMs, which may be helpful for the further study on thermal energy storage.