Preparation and Phase Change Performance of Graphene Oxide and Silica Composite Na2SO4·10H2O Phase Change Materials (PCMs) as Thermal Energy Storage Materials

Abstract

In this study, a novel nucleating agent composed of graphene oxide (GO) and silicon dioxide (SiO₂) (GO-SiO₂) is developed. GO is used as a skeleton material through which SiO₂ nanomaterials are absorbed and subsequently incorporated into Na₂SO₄·10H₂O phase change materials (PCMs). Furthermore, this study examines the phase change performance of the composite Na₂SO₄·10H₂O materials. Fourier-transform infrared (FTIR) spectra confirmed the physical combination of GO with a SiO₂ nanoparticles. Scanning electron microscope (SEM) results showed that the GO-SiO₂ composite exhibited a layered structure and excellent dispersibility. The GO-SiO₂ composite Na₂SO₄·10H₂O PCMs displayed a low level of supercooling, i.e., about 1.2 °C with the addition of GO-SiO₂ at 2.45 wt%. This was because the synergistic relation of the GO and the high dispersion SiO₂, imparted more nucleation sites for Na₂SO₄·10H₂O. Additionally, the prepared PCMs achieved high phase change latent heat and thermal conductivity, even under these conditions. The results show that the GO-SiO₂ in the Na₂SO₄·10H₂O exhibited advantageous application prospects for the improvement of the thermal performance of hydrate salts.

Keywords: graphene oxide; inorganic hydrate salt; phase change materials; supercooling; thermal energy storage.