纤维复合二氧化硅气凝胶材料的制备

摘要

Silica aerogel is a light porous material,and it owns excellent thermal insulating property.Monolithic bulk of silica aerogel composite with high pure glass fiber were prepared through controlling the gelation time during sol-gel process,and drying in ambient pressure/supercritical pressure.The composite material owns better mechanical properties than pure silica aerogel.The as-prepared samples are analyzed and characterized by X-ray diffraction (XRD),nitrogen adsorption (BET),mercury intrusion method (MIP),field emission scan-ning electron microscopy (FESEM)and thermo analysis.The results show that fiber reinforced aerogels own good mechanical properties,while retain high surface area,low density and low thermal conductivity.%二氧化硅气凝胶是一种轻质多孔结构材料，具有良好的绝热性能，但其存在机械性能较差的缺点。在溶胶-凝胶法制备气凝胶的过程中，通过对凝胶时间的调控，将高纯二氧化硅玻璃纤维复合于二氧化硅气凝胶中，然后分别采用常压干燥和超临界干燥两种方法制备了气凝胶块体样品。通过 X 射线衍射(XRD)、比表面积测试(BET)、压汞法(MIP)、场发射扫描电镜(FESEM)、热导率等实验手段对制得的样品进行表征和分析，并与纯二氧化硅气凝胶进行对照。结果表明，复合材料在保持较高比表面积、低密度和低热导率的同时，有效地改善了气凝胶的抗弯曲性能。