碳纤维-纳米石墨片网络体导热增强石蜡相变储能复合材料的制备及表征

以石蜡为代表的固-液相变储能材料存在导热率低和热稳定性差两大问题,为了提高其导热性能,以酚醛树脂为碳质黏结剂前驱体,采用浆料成型法制备碳纤维-纳米石墨片(CF-GNP)复合网络体,并通过真空浸渍石蜡,制得CF-GNP/石蜡复合材料。表征和分析了CF和GNP含量对CF-GNP网络体微观形貌和CFGNP/石蜡相变储能复合材料导热效率及热稳定性的影响。结果表明,CF-GNP/石蜡复合材料的导热效率较纯石蜡大幅增加。CF-GNP网络体中CF含量越低,GNP导热增强效应越明显。CF-GNP网络体中CF和GNP含量分别为50wt%、10wt%时,CF-GNP/石蜡复合材料的升温时间较CF含量为50wt%的CF/石蜡复合材料缩短了39.9%,当CF含量分别为70wt%和85wt%时,分别缩短了24.5%和9.4%。40次热循环稳定性测试表明,CF-GNP/石蜡复合材料具有良好热稳定性。

Preparation and characterization of paraffin phase change composites reinforced by carbon fiber-graphite nanoplatelets network

Two main drawbacks of most phase change materials are the low thermal conductivity and thermal stability. To address the above-mentioned problems, carbon bonded carbon fiber-graphite nanoplatelets (CF-GNP) network was first prepared using a slurry molding method. And molten paraffin was infiltrated into the CF-GNP network to form a CF-GNP/paraffin phase change composites. The effects of CF and GNP contents on the structure of the CF-GNP network and thermal properties of the CF-GNP/paraffin composites were systematically studied. The results show that the melting-solidifying rates are greatly accelerated for the CF-GNP/paraffin composites comparing to pure paraffin. The less the CF loading amount is, the more the effect of GNP on heat enhancement is. For the CF-GNP/paraffin composites with 50wt% CF and 10wt% GNP in the CF-GNP network, the melting time is shortened by 39.9% comparing with the CF/paraffin composite with only 50wt% CF in network. The decrements are 24.5% and 9.4% for CF/paraffin composite with CF loading of 70wt% and 85wt%, respectively. The tests of 40 thermal cycles indicate that the CF-GNP/paraffin composites prepared in this study show good thermal stability.