聚乙二醇/SiO_2定形相变材料在沥青中的相变储热性能

Phase change heat storage properties of PEG/SiO_2 shape-stabilized phase change materials in asphalt

利用多孔二氧化硅的良好吸附性,将不同计量的聚乙二醇在硅溶胶胶凝过程中吸附于硅凝胶的孔隙结构中制备聚乙二醇/二氧化硅定形相变材料(PEG/Si O_2 SSPCM);并将其与熔融沥青共混获得不同聚乙二醇含量的沥青-定形相变材料(Asphalt-SSPCM)。借助孔径分析仪和扫描电镜(SEM)表征了载体二氧化硅孔结构和PEG/Si O_2 SSPCM的表观形貌;通过X射线衍射仪(XRD)、综合热分析仪(DSC/TG)和傅里叶红外光谱仪(FTIR)考察了沥青中PEG/Si O_2 SSPCM的晶体结构、储热性能、热稳定性及化学兼容性;通过本文作者课题组研发的温度模拟试验箱测试了Asphalt-SSPCM的降温效果。结果表明,二氧化硅凝胶具有丰富的孔结构并能将聚乙二醇吸附于其介孔结构中;沥青中PEG/Si O_2 SSPCM仍含有聚乙二醇晶体,其储热能力随聚乙二醇含量的增加而增大,当聚乙二醇含量为76.1%时,相变焓高达117.5J/g,且不同聚乙二醇含量的沥青-定形相变材料均表现出良好的热稳定性;PEG/Si O_2 SSPCM与沥青的化学兼容性良好,二者之间仅是物理作用;Asphalt-SSPCM的降温效果显著,可有效改善沥青路面的高温性能;并基于相变理论,分析了沥青-定形相变材料的相变储热原理。

Considering the excellent adsorptive performance of porous silica,we prepared the polyethylene glycol/silicon dioxide shape-stabilized phase change materials（PEG/Si O_2 SSPCM）by impregnating different amounts of polyethylene glycol into the pore structure of silicon dioxide gel.And asphalt-shape-stabilized phase change materials blends（Asphalt-SSPCM）with different amounts of polyethylene glycol were prepared by the melt blending method.The pore structure of silicon dioxide and morphology of PEG/Si O_2 SSPCM were characterized by using porosity analyzing instrument and scanning electron microscope（SEM）.The crystal structure,chemical compatibility,heat storage property and heat stability of PEG/Si O_2 SSPCM in asphalt were studied by X-ray powder diffraction（XRD）,Fourier transforming infrared spectrum（FTIR）and synthesized thermal analyzer（DSC/TG）.The results showed that silicon dioxide had porous microstructure with high surface area,which can absorb polyethylene glycol. Polyethylene glycol crystals still existed in the Asphalt-SSPCM,and the heat storage ability of the Asphalt-SSPCM increased with increasing the polyethylene glycol amount in the blends. The enthalpy of the blends was 117.5 J/g with 76.1% polyethylene glycol,and the blends with different amounts of polyethylene glycol all showed favorable heat stability and cooling effect,but there was only physical interaction between Asphalt-SSPCM. Moreover,the heat storage principle of Asphalt-SSPCM was analyzed based on the phase change theory.