Microencapsulated phase change materials with TiO2-doped PMMA shell for thermal energy storage and UV-shielding

Microcapsules with thermal energy storage and UV-shielding functions were successfully prepared by the method of suspension-like polymerization in order to reduce the damage of ultraviolet light. The bifunctional microcapsules (MPCMs/TiO2) consist of n-octadecane as core material and poly (methyl-methacrylate) (PMMA) doped with titanium dioxide nanoparticles as shell material. The scanning electronic microscope (SEM) micrographs and particle size distributions showed that the as-prepared microcapsules are spherical and about 10-20 mu m in average diameter. It was confirmed by Fourier transformation infrared spectroscope (FTIR) and energy dispersive spectrometer (EDS) spectra that modified TiO2 nanoparticles had been well fixed in the cross linked network structure of PMMA shell. In addition, the results of differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA) and ultraviolet visible spectrophotometer (UV-vis) measurements demonstrated that the microcapsules exhibited high thermal storage capability, good thermal reliability and stability, and good UV-shielding property. The resultant samples of MPCMs/TiO2 may become the potential materials in the advanced applications of intelligent textile.