Bifunctional Paraffin@CaCO3:Ce3+ Phase Change Microcapsules for Thermal Energy Storage and Photoluminescence

Novel phase change microcapsules (micro-PCMs) composed of a paraffin core and aCe3+-doped calcium carbonate (CaCO3:Ce3+) shell was designed by self-assembly precipitation. The morphology, composition, and structure of microcapsules were analyzed by scanning electron microscopy, X-ray diffraction, energy-dispersive spectrometry, and X-ray photoelectron spectroscopy. The paraffin@CaCO3:Ce3+ microcapsules had regular spherical shapes and core–shell structures. Rare earth element Ce3+ was successfully introduced into the crystal lattice of CaCO3, partially replacing calcium ions. The microcapsules had good thermal regulation ability, high sealing, and energy storage efficiency. Most importantly, the luminescence intensity of paraffin@CaCO3:Ce3+ microcapsules were further enhanced with the increase of Ce3+ concentration. The paraffin@CaCO3:Ce3+ microcapsules developed in this study provide a new idea about bifunctional microcapsules and open up the application field of microcapsules.