硅藻土制备介孔SiO_2气凝胶  

Preparing Mesoporous Silica Aerogels from Diatomite

作　　者：王宝民[1] 宋凯[1] 韩瑜[1] 张婷婷 王立久[1] 

机构地区：[1]大连理工大学土木工程学院,大连116024 [2]帝国理工大学环境与水资源工程研究中心

出　　处：《土木建筑与环境工程》2013年第2期141-146,158,共7页Journal of Civil,Architectural & Environment Engineering

基　　金：国家自然科学基金(51178085);海岸和近海工程国家重点实验室开放基金(LP1109);大连市科技计划项目(2012A13GX024)

摘　　要：采用响应面法对由硅藻土制取水玻璃的工艺进行优化,进而选择最佳工艺参数在常压干燥下成功合成了SiO2气凝胶材料。试验结果表明:当碱硅比为3∶10,NaOH溶液浓度为10%,反应温度为90℃时,水玻璃模数测定值与SiO2溶出率的加权平均值达到最大值79.91%;利用N2物理吸附、FESEM、TEM、FT-IR、TG/SDTA对气凝胶的基本性能和形貌结构进行了研究。结果表明,制备得到的气凝胶密度为0.132～0.143g/m3,比表面积达755.5m2/g,形貌为不规则纳米晶粒堆积而成的海绵状结构,孔径分布集中,经改性后的气凝胶的疏水性可保持到400℃左右。Response surface methodology was adopted to optimize waterglass preparation process,and silica aerogels were synthesized under ambient pressure drying with optimum condition.Experimental results show the optimum conditions are： alkali-silica ratio 3∶10,alkalinity 10%,and reaction temperature 90 ℃.The morphology structure and other properties of silica aerogel based on diatomite were characterized by N2 physical adsorption,XRD,FESEM,TEM,FTIR and TG/SDTA measurement.The results indicate that silica aerogel is crack-free amorphous state solid,with the density 0.132~0.143 g/m3 and the specific surface area 755.5 m2/g,and it exhibits a sponge structure and a narrow pore size distribution.In addition,the hydrophobicity of aerogel can maintain up to 400 ℃.

关 键 词：硅藻土 水玻璃 响应面法 SIO2气凝胶 介孔 

分 类 号：X703.5[环境科学与工程—环境工程]