石蜡@TiO2/CNTs复合相变材料制备及其热物性

Preparation and thermal physical properties of paraffin@TiO2/CNTs composite phase change materials

采用界面聚合法合成石蜡@TiO2/CNTs复合相变材料,通过扫描电子显微镜(SEM)、傅里叶红外光谱(FT-IR)和X射线衍射(XRD)分析了复合材料的微观形貌、化学组成和晶体结构;采用差示扫描量热仪(DSC)、热重分析仪(TGA)及导热系数仪分析了复合材料的相变性能、热稳定性和热导率。结果表明:石蜡@TiO2/CNTs复合材料由具有核-壳结构的石蜡@TiO2微胶囊与碳纳米管(CNTs)复合而成,碳纳米管通过氢键吸附在微胶囊的表面;复合材料的熔点及凝固点比纯石蜡高,碳纳米管质量分数为1%的复合材料的相变潜热为59.57 J/g,且随着碳纳米管质量分数的增大而减小,复合材料在170℃以下具有良好的热稳定性,热导率显著提高。

Paraffin@TiO2/CNTs composite phase change materials were prepared by interfacial polycondensation method and their micro-morphology, chemical compositions and crystalline structure were characterized by scanning electron microscopy(SEM), Fourier transform infrared spectroscopy(FT-IR) and X-ray diffractometer(XRD). The thermal properties, thermal stability and thermal conductivity of the composite were measured by differential scanning calorimeter(DSC), thermo-gravimetric analyzer(TGA) and thermal conductivity meter. The results show that the paraffin@TiO2/CNTs composite was composed of core-shell paraffin@TiO2 microcapsules and carbon nanotubes that are adhered on the surface of the microcapsules through hydrogen bonding. The melting point and freezing point of the paraffin@TiO2/CNTs composite were higher than those of pristine paraffin. The phase change latent heat of the composite containing 1% carbon nanotubes was 59.57 J/g and it decreased with increasing content of carbon nanotubes. The composite had good thermal stability below 170 ℃ and its thermal conductivity was significantly improved.