不同温度长时间作用下SiO_2气凝胶结构和性能的变化  

Impacts of Structural Change of SiO_2 Aerogel Under Different Time and High Temperature Conditions on Insulation Performance

作　　者：周长灵[1] 杨杰[1] 隋学叶[1] 刘瑞祥[1] 张文苑[1] 王重海[1] 

机构地区：[1]山东工业陶瓷研究设计院有限公司,淄博255000

出　　处：《现代技术陶瓷》2014年第5期11-16,共6页Advanced Ceramics

摘　　要：针对SiO2气凝胶高温结构变化规律对隔热性能的影响,在500℃,600℃,700℃和800℃不同时间（0-12h）作用下,对热处理后的SiO2气凝胶结构和组成进行测试和分析;结果表明,500℃,600℃条件下,随着时间的延长,重量损失和厚度上的收缩略微增大,体积密度不变;700℃和800℃条件下,随着时间的延长,厚度上的收缩逐渐增加,体积密度逐渐增大,重量损失增大。在200-1200℃时,对热处理0.5h后的SiO2气凝胶结构和组成进行测试和分析。结果表明：当热处理温度为200-800℃时,气凝胶中小孔隙坍塌,大孔隙增多,密度基本不变,其骨架结构未被破坏;二次堆积颗粒逐渐增大且相互融合,密度急剧增加;当热处理温度达到1000-1200℃时,气凝胶骨架结构遭到明显破坏,隔热性能失效。To study the impacts of structural change of SiO2 aerogel on its insulating properties,the samples were treated in long time（0-12h）in 500℃,600℃,700℃ and 800℃.The results show that the shrink extends in thickness and the weight loss under the 500℃and 600℃with the time increased,the density is basically unchanged.As for 700℃ and 800℃,the same results were treated with 0-12h,the shrink extends in thickness,the weight loss and density increases considerably.Besides,the structure and composition of SiO2 aerogel after the different temperature treaded with 0.5h were tested.The results show that when the heat treatment temperature is between 200-800℃,the small pores in SiO2 aerogel collapses and large pores increase,and the density is stil1 able to maintain the 1ow value due to the unbroken skeleton.When the heat temperature is between 800-1000℃,the secondary particle size increases and the rnutual integration of the secondary particles occurs,the density will be significantly increased.When the heat treatment temperature is up to 1200℃,the structure of SiO2 aerogel is obviously damaged,which results in the failure of the insulation performance.

关 键 词：SIO2气凝胶 隔热材料 结构变化 隔热性能 

分 类 号：TQ127.2[化学工程—无机化工]