Study On Preparation And Properties Of Organic Acid/Silica Composite Phase Change Material For Thermal Storage

With the deep development and research of phase change materials for energy storage technology, composite phase change material has been widely appreciated, including the composite of organic phase change material and inorganic matrix material. such materials contain the advantages of organic phase change materials and overcome the disadvantages of liquid leakage during the phase change process. On this basis, composite phase change material was prepared by different method with organic phase change material and inorganic silica matrix material, and studied the optimal preparation conditions, and material microstructure and thermal properties.Stearic acid was imbedded into the net of silicon dioxide (SiO2) to preparing stearic acid/silicon dioxide phase change energy storage composite material by sol-gel method in the research, stearic acid as phase change materials and silicon dioxide as matrix materials. The morphology, structure and thermal performance of the composite were characterized by several means such as FE-SEM, XRD, FT-IR and TG-DSC. The obtained results show that, the sol-gel preparation of stearic acid/silica composite phase change material, and through the characterization of sample preparation, stearic acid embedded into a three-dimensional network of silicon dioxide. Uniform phase change material embedded into SiO2network space, the phase transition does not leak. Silica as the base material while forming space heat grid, a larger increase of the thermal conductivity of the phase change material. When the reaction conditions is that pH is3, the reaction temperature is70℃, the reaction time is3h; There is no chemical reaction between stearic acid and silicon dioxide; The particle size of composite phase chang materials is uniform about1～2μm in diameter; Composite phase change temperature and latent heat of adipic acid/silica composite phase change materials is76.7℃and74.05J/g.Adipic acid was imbedded into the net of silicon dioxide (SiO2) to preparing adipic acid/silicon dioxide phase change energy storage composite material by hydrothermal synthesis in the research, adipic acid as phase change materials and silicon dioxide as matrix materials. The morphology, structure and thermal performance of the composite were characterized by several means such as FE-SEM, XRD, FT-IR and TG-DSC. The obtained results show that, adipic acid/silica composite phase change materials between adipic acid and silicon dioxide is a simple relationship between the physical engagement, there is no new substance, indicating that the hydrothermal reaction between the material component does not change adipic phase change energy storage properties of the host material. When the reaction conditions is that pH is5, the reaction temperature is150℃, the reaction time is4h; There is no chemical reaction between adipic acid and silicon dioxide; The particle size of composite phase chang materials is uniform about1-2μm in diameter; Composite phase change temperature and latent heat of adipic acid/silica composite phase change materials is139.0℃and48.82J/g. Composite phase change material for thermal storage after150thermal cycling test still has good thermal stability.