勃姆石纤维增强二氧化硅气凝胶的制备及性能  

Fabrication of Boehmite Fiber-reinforced Silica Aerogels and Their Performances

作　　者：张洁 银波 刘玮欣 刘兴平 连文贤 唐韶坤[1] ZHANG Jie;YIN Bo;LIU Weixin;LIU Xingping;LIAN Wenxian;TANG Shaokun(Key Laboratory for Green Chemical Technology of Ministry of Education,School of Chemical Engineering&Technology,Tianjin University,Tianjin 300072,China;Xinte Energy Co.,Ltd.,Wulumuqi 830019,China)

机构地区：[1]天津大学化工学院,绿色合成与转化教育部重点实验室,天津300072 [2]新特能源股份有限公司,乌鲁木齐830019

出　　处：《高等学校化学学报》2022年第11期98-106,共9页Chemical Journal of Chinese Universities

摘　　要：以六水合氯化铝为铝源,通过水热法制备勃姆石纤维;以甲基三甲氧基硅烷和正硅酸乙酯为硅源共前驱体,采用溶胶-凝胶法进而常压干燥制备了勃姆石纤维掺杂的二氧化硅复合气凝胶;探究了勃姆石纤维的掺杂量对复合气凝胶性能的影响.当勃姆石纤维的掺杂量(质量分数)为1%时,气凝胶的机械性能最好,能够承受17.1%的压缩应变,最大压缩强度为1.12 MPa,压缩模量高达2.57 MPa,复合气凝胶在150℃仍然具有较低的导热系数(0.0670 W·m^(-1)·K^(-1)).勃姆石纤维能够一定程度地抑制二氧化硅颗粒在高温下的烧结和相转变,对二氧化硅气凝胶的耐高温性能有显著的提升作用,复合气凝胶在1100℃高温热处理后,仍能保持良好的隔热性能和较高的机械强度.Boehmite fibers were prepared using aluminum chloride hexahydrate as aluminum source by a hydrothermal method.Silica composite aerogels doped with boehmite fibers were then fabricated using methyltrimethoxysilane and tetraethoxysilane as silicon co-precursors after the sol-gel process and ambient pressure drying.The effect of the boehmite fiber content on the composite aerogel was studied.When the content(mass fraction)of boehmite fibers to silicon sol is 1%,the aerogel obtains the optimal mechanical properties,which can withstand 17.1%compressive strain,the maximum compressive strength is 1.12 MPa and the compressive modulus is as high as 2.57 MPa.The composite aerogels show low thermal conductivity of 0.0670 W·m^(-1)·K^(-1)at 150℃.Moreover,it is found that the boehmite fiber can inhibit the sintering and phase transformation of silica particles at elevated temperature and thus enhance the high temperature resistance of silica aerogels.Accordingly,the silica-boehmite fiber composite aerogel can still maintain good thermal insulation performance and high mechanical strength at a high temperature of 1100℃.

关 键 词：二氧化硅气凝胶 勃姆石纤维 耐高温性能 

分 类 号：O648[理学—物理化学]