Fabrication of paraffin@SiO2 shape-stabilized composite phase change material via chemical precipitation method for building energy conservation

A novel paraffin@SiO2 shape-stabilized composite phase change material (ss-CPCM) was fabricated by chemical precipitation process using sodium silicate precursor. Various techniques were used to characterize the as-prepared paraffin@SiO2 ss-CPCM so as to investigate its structure and thermal properties, including Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and thermal conductivity measurement. The SEM results show that the microstructures of the prepared ss-CPCM are some uniform submicron particles. The FTIR and XRD results showed that there was no chemical interaction between paraffin and SiO2 matrix. The DSC analysis results indicated that the paraffin@SiO2 ss-CPCM achieved high encapsulation efficiency and desirable latent heat storage capability. The thermal conductivity of the composite was also significantly improved compared with pure paraffin. According to the TGA results and the thermal cycling tests, the prepared ss-CPCMs had a good thermal stability. The prepared paraffin@SiO2 ss-CPCM with enhanced heat transfer and phase change properties holds great promise for building energy conservation owing to the low cost of raw materials and the simple synthetic technique.