Preparation and characterization of binary fatty acid/SiO_2 composite phase change energy storage materials

In order to prepare shape-stabilized phase change energy storage materials which were applied to control temperature of building materials,capric acid was mixed separately with lauric acid,myristic acid and palmitic acid to prepare binary fatty acid eutectic mixtures.The phase transition temperature of binary fatty acid and its corresponding mixing proportion are calculated based on Schroder equation.Shape-stabilized CA-MA/SiO2 composite phase change materials were prepared using sol-gel methods.The structure,microstructure,thermal properties and thermal stability of composite materials were characterized by infrared spectroscope,scanning electronic microscope,differential scanning calorimeter and thermogravimetric analysis apparatus,respectively.It was shown that as prepared binary fatty acid had an appropriate temperature and latent heat which can be applied in building field.The CA-MA was well dispersed in the porous network of SiO2,and there was no chemical interaction between CA-MA and SiO2.The melting temperature and melting latent heat of the composite phase change materials is 20.96℃ and 70.17J/g,respectively,and composite materials have good thermal stability.So the composite materials were considered as an effective latent heat thermal energy storage materials in building energy conservation.