重复使用对纤维增强SiO_(2)气凝胶材料隔热性能的影响

Effect of repeated usage on thermal insulation properties of fiber reinforced SiO_(2) aerogel materials

以纤维增强SiO2气凝胶为研究对象,采用石英灯红外辐射加热,将样品热面置于650℃的环境下保温4h,研究了重复使用(10、20、30次)对材料隔热性能的影响并分析了相关机制。结果表明:随着重复使用次数的增加,纤维增强SiO2气凝胶隔热性能发生衰减。重复使用10次,冷面温度为106℃;重复使用30次,冷面温度已经升高至124℃。通过对样品的显微结构、组成、孔结构和比表面积等分析发现:在冷热重复使用过程中,SiO2气凝胶纳米颗粒会因烧结而长大,材料比表面积和总孔体积明显降低,这是导致隔热性能随着重复使用次数增加而发生衰减的主要原因。

Fiber reinforced SiO 2 aerogel was studying object.The hot surface of a sample was heated by a quartz lamp with infrared radiation at 650℃for 4 h.The influence of the reuse times(10,20,and 30)on the thermal insulation performance of the material was studied and the mechanism was analyzed.The results show that the thermal insulation properties of the fiber reinforced SiO 2 aerogel attenuate with the increasing reuse times.The temperature of the cold surface reaches 106℃and even 124℃,respectively,when the hot surface of the specimen is reused for 10 times and 30 times.By analyzing the microstructure,composition,pore structure and specific surface area of the sample,it is found that during the reuse in hot and cold alternant conditions,silica aerogel nano particles grow up due to the sintering,and the specific surface area and total pore volume of the material are significantly reduced,which is why the thermal insulation performance attenuates with the increasing reuse times.