聚乙二醇/二氧化硅/膨胀石墨相变储能材料的制备与性能研究

本文以聚乙二醇(PEG)为有机组分,膨胀石墨(EG)的多孔结构为材料载体,以二氧化硅(SiO_2)的网状结构完成封装,通过溶胶凝胶法和真空浸渗法相结合,制备具有良好导热能力的聚乙二醇/二氧化硅/膨胀石墨定形相变材料。通过DSC、TG、XDR和导热系数测试分析复合材料的结构和性能,测试结果表明:聚乙二醇最大质量分数为84%,膨胀石墨质量分数为6%,材料没有液相泄露,相变温度为59.9℃,潜热值为129J/g,导热系数为1.867W/(m·k),且热稳定性良好;另外,导热系数与复合体系中膨胀石墨的质量分数为指数关系,此材料为中温潜热蓄热提供了一种蓄热介质选择,在热泵供热、太阳能利用、余热回收等领域有广阔的应用前景。

In the paper, PEG/SiO2/EG shape-stabilized phase change material with high thermal conductivity were prepared through sol-gel method and vacuum impregnation method. PEG was as the organicof this material and EG was as the carrierof this material and SiO2 was used to package material. The structure and properties of the composites are tested by DSC, TG, XDR and thermal conductivity coefficient.The test results show thatthe material has no liquid phase leakage when the maximum mass fraction of PEG is 84% and the EG mass fraction is 6%;and its phase transition temperature is 59.9℃, the latent heat is 129J/g, the thermal conductivity is 1.867W/（m·K）, and the thermal stability is good. In addition, the coefficient of thermal conductivity and the mass fraction of the expanded graphite in the composite system are exponential.This material provides a heat storage medium for the medium temperature latent heat storage, and has broad application prospects in the field of heat pump, solar energy utilization and so on.