氧化铝包覆金属锡相变微胶囊的制备及相变性能研究

Preparation and Phase Change Properties of Metallic Tin Phase Change Microcapsules Coated by Al_(2)O_(3)

以金属Sn为相变材料,采用溶胶–凝胶包覆法和高温热处理制备出具有核壳结构的Sn@Al_(2)O_(3)相变储热微胶囊。利用粉末晶体X射线衍射仪(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)、电子探针显微分析仪(EPMA)和差示扫描量热分析仪(DSC)对样品进行性能分析。研究了不同气氛下高温热处理对核壳结构的影响,同时对微胶囊样品进行热循环稳定性表征。结果表明:Sn@Al_(2)O_(3)相变微胶囊的壳层厚度为1~3μm之间,且具有SnO_(2)-Al_(2)O_(3)双层壳结构;在氧气和氮气气氛下热处理分别获得Sn@Al_(2)O_(3)-O_(2)和Sn@Al_(2)O_(3)-N2微胶囊样品的相变温度均约为233℃,相变潜热分别为52.0 J/g和54.5J/g。经过100次循环测试后,Sn@Al_(2)O_(3)-O_(2)相变微胶囊表现出良好的循环热稳定性。

Sn@Al_(2)O_(3)microcapsules with core-shell structure using Sn as phase change material were prepared by a sol-gel coating method and subsequent high temperature heat treatment.The samples were characterized by powder X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),electron probe micro-analyzer(EPMA)and differential scanning calorimeter(DSC).The infuence of core-shell structure under high temperature heat treatment under different atmospheres was further studied,and the thermal cycling stability of the obtained phase change microcapsules was measured.The results showed that the shell thickness of Sn@Al_(2)O_(3)microcapsules was 1~3μm with SnO_(2)-Al_(2)O_(3)double-layer shell.The phase transition temperatures of Sn@A_(2)O_(3)-O_(2)and Sn@Al_(2)O_(3)-N_(2)microcapsules obtained by heat treatment in oxygen and nitrogen atmosphere were about 233℃,and the latent heat was 52.0 J/g and 54.5 J/g,respectively.After 100 cycles,Sn@Al_(2)O_(3)-O_(2)showed an excellent cyclic thermal stability.