磁控Fe_(3)O_(4)排布改性石蜡基相变材料的制备及性能

Preparation and properties of paraffin-based phase change materials with different magnetically regulated Fe_(3)O_(4)arrangement

为探究纳米填料排布对相变材料导热性能的影响,以石蜡为相变材料基材,以自制的Fe_(3)O_(4)纳米颗粒为导热纳米填料,在外部磁场的调控下制备了具有不同纳米填料排布特征的复合相变材料。通过XRD、FTIR、SEM对制备的Fe_(3)O_(4)纳米颗粒和复合相变材料的化学结构与微观形貌进行了表征,并测定了复合相变材料的热性能。通过影像测量仪和能谱仪观察纳米填料的排布情况,并构建了具有不同纳米填料排布特征的复合相变材料的有限元模型,计算探究纳米填料的不同排布对复合相变材料导热性能的影响。结果表明,Fe_(3)O_(4)纳米颗粒粒径为40~50 nm,磁性响应性能优异。复合相变材料相变温度变化较小,相变潜热在134.3~148.1 J/g范围内。Fe_(3)O_(4)纳米填料在磁场调控下形成的“山峰”排布区域高度越高,面积越大,复合相变材料的导热系数越大,且导热系数最高提升了34%。采用有限元仿真模拟相变材料传热过程温度场,进一步验证了优化Fe_(3)O_(4)纳米填料分布可提高相变复合材料的导热性能。

The composite phase change material(PCM)was prepared by using paraffin as substrate and self-made Fe_(3)O_(4)nanoparticles as thermal conductive nano-filler.In order to investigate the effect of nano-filler arrangement on the thermal conductivity of PCM,the composite PCM with different characteristics of nano-filler arrangement was prepared under the control of magnetic field.The chemical structure and microstructure of Fe_(3)O_(4)nanoparticles and PCM composites were characterized by XRD,FTIR and SEM,and the thermal properties of PCM composites were measured.The arrangement of nano-filler was observed by image measuring instrument.According to the actual arrangement which were displayed by image measuring instrument and EDS,the finite element model of PCM with different arrangement of nano-fillers was constructed.The influence of different arrangements of nano-fillers on the thermal conductivity of PCM was calculated as well.The results show that the size of Fe_(3)O_(4)nanoparticles is 40-50 nm,and their magnetic response performance is excellent.The phase change temperature is small,and the phase change latent heat is in the range of 134.3-148.1 J/g.The higher the height and the larger the area of the“mountain”arrangement region formed by the nano-fillers,the greater the thermal conductivity of the composite PCM.The thermal conductivity has been increased by up to 34%.Moreover,the finite element simulation explored the temperature field of the heat transfer process and further verified that the thermal conductivity of the phase change composites can be improved by optimizing the distribution of Fe_(3)O_(4)nanofillers.