Preparation of phase change microcapsules with high thermal storage and temperature sensitive for thermal management

Preparing microcapsules with core-shell structure by encapsulating phase change materials (PCM) in the shell is considered as an effective method to solve the leakage problem of PCM during use. Herein, a phase change microcapsule (MPCM) based on n-eicosane core and polyurea shell was prepared. This MPCM was prepared by interfacial polymerization of isophorone diisocyanate (IPDI) and ethylenediamine (EDA) using Pickering emulsion as a template and sulfonated lignin (SL) derived from industrial by-products as an emulsifier. The morphology, chemical structure and optimal preparation conditions of the MPCM were investigated by polarized light microscopy, fourier infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The results showed that the SL emulsified n-eicosane oil-in-water emulsion particles had good dispersion and homogeneous particle size. MPCM-2 with combined optimal conditions in MPCM exhibited regular spherical shape, high enthalpy of phase change (209.8 J/g), high encapsulation ratio (82.9 %), good thermal cycling stability, and negligible leakage rate. When PDMS and MPCM-2 were compounded and applied to thermal management, the MPCM-2/PDMS composite exhibited a much slower temperature rise and fall. Moreover, a plateau period appears at the crystallization and melting temperatures. Moreover, the phase change energy storage of MPCM/PDMS could be easily observed by the change of color after the introduction of temperature-sensitive particles. In summary, the present MPCM has good thermal storage and thermal management capabilities and provides a good application prospect for thermal energy storage systems.