碳纳米管/有机酸复合相变材料的制备及性能

Preparation and properties of multi-wall carbon nano-tube/organic acid composites phase change materials

摘要:

以多壁碳纳米管（MWNT）为支撑材料，十二酸（LA）、十四酸（MA）、十六酸（SA）和十八酸（PA）为相变主材，采用熔融共混法制备不同成型复合相变材料。利用压片机、红外热成像仪、导热系数测试仪和电阻率测试仪对成型材料的物理性质、温度场分布、蓄-放热时间、导热率和电阻率进行测试。结果表明，成型压力和MWNT添加量对复合材料密度影响较小。4种有机酸中分别添加24%、19%、25%和26%的MWNT时，有机酸不会泄漏。成型后虽然温度场分布更均匀，且具有良好疏水性，但蓄热速度减缓。复合材料导热率分别比纯有机酸提高2.7~3.7倍、2.7~4.5倍、2.7~4.4倍和1.7~2.4倍。压力从1MPa变到11MPa时，复合材料电阻率分别减小75.9%、76.5%、72.2%和74.0%，材料电阻率变化曲线拟合表明两者之间相关性较高。说明制备的复合相变材料具有良好的疏水、导热和导电性能。

Abstract:

Lauric acid (LA), myristic acid (MA), palmitic acid (PA) and stearic acid (SA) were used as the main phase change materials, multi-wall carbon nano-tube (MWNT)for the framework. All the composite materials were prepared by melt-blending method. Physical Properties, temperature field distributions, heat store and release time, thermal conductivities and resistivities of composites as form-stable phase change materials were characterized by tablet pressing machine, infrared thermal image, thermal conductivity instrument and resistivity meter. The results show that molding pressure and contents of MWNT had no distinct influence on density of composites phase change materials. The four acidic organic matter, adding MWNT with the mass fraction of 24%, 19%, 25% and 26%, had no leakage occurred. Although the temperature field distribution was more uniform after molding, and has good hydrophobicity, the heat storage rate slows down. The thermal conductivities of the composite materials were respectively 2.7 ~ 3.7 times, 2.7 ~ 4.5 times, 2.7 ~ 4.4 times and 1.7 ~ 2.4 times than the corresponding pure organic acids. When the pressure changed from 1MPa to 11MPa, the resistivity of the composite materials decreased by 75.9%, 76.5%, 72.2% and 74.0%, respectively. The fitting of the change curve of the resistivity of the material showed a high correlation between them. It shows that the prepared composite phase change material has good hydrophobicity, thermal and electrical conductivity.