关键词: 石蜡, 碳气凝胶, 相变储热材料, 微观结构, 储热性能

Abstract:

The building energy consumption can be reduced with the utilization of paraffin for walls，but an easy leakage of this material seriously affects the extensive application of composite phase change heat storage materials，which is expected to be solved by using carbon aerogel with large adsorption capacity as adsorption carrier.In order to further improve the paraffin adsorption performance，the surface of carbon aerogel was modified with trimethylsilyl chloride in different concentrations and the surface microstructure evolution of carbon aerogel was investigated by XRD，SEM and FT-IR.The experiment manifested that the —Cl—Si（CH₃）₃ group of trimethylchlorosilane could branch with —OH on the surface of carbon aerogel in the process of modification，which enriched the amount of —CH₃ on the surface of the sample，improved the hydrophobicity and pore structure of the product，and improved its ability to adsorb non-polar paraffin.When the mass concentration of trimethylsilyl chloride reached 30%，the carbon aerogel showed the best adsorption performance，and could absorb 85.87% of paraffin after full immersion.After 200 melting-condensation cycles，no obvious leakage was found and significant change was not obvious in phase change temperature and enthalpy.The composite phase change material had excellent structural stability and thermal insulation performance，which provided new ideas for the development of new wall insulation materials.

Key words: paraffin, carbon aerogels, phase change heat storage materials, microstructure, heat storage performance