Preparation and Characterization of n-Nonadecane/CaCO3 Microencapsulated Phase Change Material for Thermal Energy Storage

摘要

A novel microencapsuled thermal energy storage phase change material (MicroEPCM) based on n-nonadecane core and CaCO3 shell were synthesized via a self-assembly method. The chemical structure, surface morphology and thermal properties of the MicroEPCM were investigated by X-ray diffractometer (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA), respectively. The effects of core/shell mass ratios, stirring speed, temperature and emulsifier concentration on the morphology and thermal properties of the MicroEPCM were investigated to confirm the most suitable CaCO3-encapsulated n-nonadecane reaction conditions. The results showed that the optimal spherical morphology and the highest latent heat were obtained when the stirring rate is 800 rpm, the temperature is 45°C, the emulsifier concentration is 15 mmol/L and the core/shell mass ratio is 3:1. The latent heat and encapsulation rate of Micro- EPCM as above-mentioned are 134.83 J/g and 59.68%, respec- tively. The thermal conductivity of MicroEPCM is improved up to 3.56 times than that of prinstine n-nonadecane. The Micro- EPCM did not leak after being heated at 80°C for 20 h, which proves that the CaCO3 shell is compact. The MicroEPCM present a good thermal stability after 200 thermal cycling. The Micro- EPCM also has been proved to maintain high mechanical strength.