Preparation And Characterization Of Organic/Inorganic Shape-Stabilized Composite Phase Change Materials

Energy storage technology has important research significance for the efficient utilization of renewable energy such as solar energy and wind energy with intermittent and non-uniform characteristics.This paper mainly studies how to prepare novel organic/inorganic(lauric acid/TiO_2,decanol/TiO_2,lauryl alcohol and caprylic acid/activated charcoal)composite phase change energy storage materials and characterize their chemical composition,micro-morphology and thermal properties.The microencapsulated phase change material was prepared by sol-gel method using lauric acid（LA）as core material and titanium dioxide（TiO₂）as shell material and the relevant properties were characterized.The results showed that there was no chemical reaction between LA and TiO₂ in the microcapsules,and LA was coated with TiO₂ and formed micron-sized spherical particles.The composites with 43.5%encapsulation ratio of the LA melted at 44.39℃with the melting enthalpy of 67.54J/g and solidified at 43.64℃with the solidification enthalpy of 65.17J/g.The thermal decomposition of the microencapsulated LA with TiO₂ shell hardly occurred under200℃.That is to say,the composites possess good thermal stability in the operating temperature range.In conclusion,the prepared microencapsulated composites can be incorporated into solar energy storage like solar air heaters and into electronic devices as heat sinks.The microencapsulated phase change material was prepared by sol-gel method using decanol as core material and titanium dioxide（TiO₂）as shell material and the relevant properties were characterized.The results showed that decanol and TiO₂ in the microcapsules have good compatibility each other.Moreover,the fire resistance of the microcapsules has been greatly improved.The most ideal sample melted at3.87℃with the melting enthalpy of 61.12J/g and solidified at-1.32℃with the solidification enthalpy of 59.54J/g.In general,the prepared microcapsules have potential for cold energy storage.The shape-stabilized composite phase change materials for cold energy storage were prepared by physical blending adsorption method.In the shape-stabilized composites,lauryl alcohol（LA）and caprylic acid（CA）were employed as phase change materials,and activated charcoal（AC）was selected as supporting material.The results displayed that the eutectics of LA and CA was well absorbed and dispersed homogeneously into the porous network structure of the AC.Moreover there was only physical absorption between the eutectic mixture and AC.The composites with the mass ratio 60%of the eutectics melted at-0.21℃with a latent heat enthalpy of 28.08J/g and solidified at-2.33℃with a latent solidification enthalpy of 29.70J/g.The prepared composites will contribute to cold energy storage of low temperature range.