Preparation and analysis of composite phase change material used in asphalt mixture by sol–gel method

• Four different kinds of CPCMs were prepared and named as PCPCM, SCPCM, FCPCM and ACPCM, respectively.
• CPCMs were analyzed by Scanning Electron Microscope (SEM) and Differential Scanning Calorimetry (DSC).
• FCPCM and ACPCM have better coating effectiveness than PCPCM and SCPCM.
• ACPCM has relatively large latent heat storage capacity and proper phase change temperature.

Based on the principle of sol–gel method and the mechanism of silane coupling agent can be used to adjust the gel structure, four different kinds of composite phase change materials (CPCMs) were prepared by using pure phase change material (PCM), silica powder adsorbed PCM, floating bead adsorbed PCM and activated carbon adsorbed PCM as raw materials via sol–gel process, the four CPCMs were named as PCPCM, SCPCM, FCPCM and ACPCM, respectively. Their coating effectiveness and the latter two CPCMs’ latent heat storage capacities were studied by scanning electron microscope (SEM) and differential scanning calorimetry (DSC). The results show: silane coupling agent can improve particle distribution of CPCMs positively, its proper mixing amount is 10% of the mass of tetraethyl orthosilicate (TEOS); compared to PCPCM and SCPCM, FCPCM and ACPCM have better coating effectiveness; compared to FCPCM, ACPCM has larger latent heat storage capacity and proper phase change temperature, it also has better high temperature stability and can meet the demand of being used in asphalt mixture.