Preparation of microencapsulated phase change materials used graphene oxide to improve thermal stability and its incorporation in gypsum materials

Graphene oxide (GO) was used as emulsifier to prepare the microencapsulated phase change materials (MePCMs) with high thermal stability and impermeability, the chemical structure, particle size distribution, micro-morphology and thermal performance of the microcapsules were investigated by Fourier transform infrared spectrometer (FTIR), laser particle analyzer, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results showed that when GO was used as emulsifier with Span80 and Tween 80, the MePCMs prepared with a higher thermal performance, the particle size are concentrated, the decomposition temperature of the MePCMs are improved, the MePCMs are prepared with a high latent heat with the paraffin content of about 49.9%, the impermeability performance of the MePCMs are obviously improved compared with the samples prepared with other emulsifiers. The gypsum materials that incorporated with different contents of the MePCMs were prepared, the compressive and flexural strength of the gypsum materials are decreased with the increase of the content of the MePCMs, when the content of the MePCMs exceeds 30%, the microcapsules begins to agglomerate in the gypsum, which results in a low compatibility of the MePCMs and gypsum matrix; the incorporation of MePCMs endow the temperature regulation performance of the gypsum building materials, the thermal conductivity of the gypsum materials are decreased as the incorporation of the MePCMs. (C) 2019 Published by Elsevier Ltd.