Preparation and Characterization of Paraffin@ZnO Microcapsule Phase-Change Material by an in Situ Precipitation Method

Abstract

Energy is closely related to human life and affects social progress and development. However, with the progress of society and the growth of the population, the energy supply shows a tense trend. To solve the imbalance between the supply and demand of energy, energy storage materials, especially phase-change materials (PCMs), have received wide attention. In this paper, a new microencapsulated phase-change material (MPCM), ZnO as the shell material and paraffin as the core material, was prepared by an in situ precipitation method. The effects of emulsifier and paraffin dosage, adsorption time, and emulsification rate on the encapsulation rate (R) and encapsulation efficiency (E) of microcapsules were systematically studied. Fourier transform infrared spectrometry (FT-IR) and X-ray diffractometry (XRD) were used to analyze the chemical and crystal structures of the microcapsules. Differential scanning calorimetry (DSC) and thermal weight analysis (TG) results show that the melting enthalpy and encapsulation efficiency of microcapsules prepared under optimal conditions are 63.62 J/g and 40.06%, respectively, and confirm that the microcapsules have good thermal stability. Besides, according to a leakage experiment, ZnO can be described as a good microcapsule shell material for paraffin MPCMs.