高炉渣基低温相变复合材料的特性表征与分析

Characterization and analysis of low-temperature composite phase change materials based on blast furnace slag

为制备性能良好的高炉渣基低温相变复合材料,本文基于真空浸渍法,研究以改性高炉渣、氧化石墨烯/石蜡复合相变材料为主要原料,采用SEM、Hot Disk及TG-DSC等检测方法分析该材料的微观结构、导热系数及相变潜热等性能,探明材料成型机理。结果表明:对高炉渣基低温相变复合材料的热性能影响程度从大到小依次为复合相变材料在改性高炉渣中的质量分数、改性高炉渣种类、氧化石墨烯在复合相变材料中的质量分数。综合考虑,以酸性改性水淬高炉渣为载体,当复合相变材料中氧化石墨烯的质量分数为4%,载体中复合相变材料的导入量为30%时,该复合材料的性能最优,材料的导热系数为0.59 W/(m·K),约为酸性改性高炉渣或碱性改性高炉渣的3倍,相变焓约为热循环前的98.82%,熔化潜热、凝固潜热分别为112.27、82.16 J/g,熔融温度、凝固温度分别为50.12、55.45℃。

In order to prepare low-temperature composite phase change materials based on blast furnace slag with good performance,based on vacuum impregnation method,the modified blast furnace slag and graphene oxide/paraffin composite phase change materials are used as main raw materials,and the microstructure,thermal conductivity and latent heat of phase change of the materials are analyzed by SEM,Hot Disk and TG-DSC to find out the molding mechanism of the materials.The results show that the degree of influence in descending order on the thermal properties of low-temperature composite phase change materials based on blast furnace slag is the mass fraction of composite phase change materials in modified blast furnace slag,the type of modified blast furnace slag and the mass fraction of graphene oxide in composite phase change materials.Considering comprehensively,with acid modified water quenching blast slag as the carrier,when the mass fraction of graphene oxide in the composite phase change materials is 4% and the introduction amount of the composite phase change materials in the carrier is 30%,the composite material has the best performance.The thermal conductivity of the material is 0.59 W/(m·K),which is about 3 times that of acid-modified blast furnace slag or alkaline-modified blast furnace slag,and the phase change enthalpy is about 98.82% of that before thermal cycle,the latent heat of melting and solidification are 112.27 and 82.16 J/g,respectively,and the melting temperature and solidification temperature are 50.12 and 55.45 ℃,respectively.