Preparation and Characterization of Glauber's Salt Microcapsules for Thermal Energy Storage

Abstract

Microcapsules with modified polymethyl methacrylate (PMMA) as coating polymer and sodium sulfate decahydrate (Na₂SO₄ · 10H₂O) as core materials were prepared using the emulsion polymerization and solvent evaporation methods. Chemical composition and microscopic structure of the synthesized PMMA-AA/Na₂SO₄ · 10 H₂O phase change materials (PCMs) microcapsules were confirmed by Fourier-transform infrared spectroscopy, polarizing optical microscopy (POM), scanning electron microscopy (SEM). The thermal properties were analyzed by differential scanning calorimetry (DSC) in detail. The results show that the microcapsules are uniform and approximately spherical with an average diameter of about 3.5 μm. The melting point of the microcapsule is 31.5°C and the fusion heat is 182.8 J/g. This demonstrated that the prepared PMMA-AA/Na₂SO₄ · 10H₂O microcapsules could be promising candidates for the design of novel energy-saving materials with good thermal energy storage application.