Preparation and characterization of nano-TiO2/paraffin-based composite phase change microcapsules

A novel phase change microcapsule with paraffin wax as the core material and nano-TiO₂ modified polysulfone resin(PSF)as the shell material was developed based on the solvent volatilization method. The composite microcapsules were characterized by Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), Differential Scanning Calorimeter (DSC) and Thermogravimetric Analysis (TGA) to test the comprehensive performance of the composite microcapsules. The results showed that the overall performance of the microcapsules was the best when the nano-TiO₂ was added at 3%, with the average particle size of 103.83 μm reaching the minimum, the melting enthalpy of 104.50 J/g, the crystallization enthalpy of 104.00 J/g, and the encapsulation efficiency of 68.54%; The chemical structure of the composite phase change microcapsules was not affected after adding a certain amount of nano-TiO₂, and the surface of the microcapsules was smoother, which increased the continuity of the microcapsules. The thermal stability and thermal properties of microcapsules were also significantly improved.