淀粉-SiO2复合气凝胶的制备

采用常压干燥工艺制备淀粉-SiO2复合气凝胶,得到了制备淀粉-SiO2复合气凝胶的最佳工艺参数,利用BET、SEM以及TG-DTA测试手段,探究了淀粉对SiO2气凝胶的孔结构、微观结构以及热稳定性的影响。结果表明,淀粉的加入能够有效增大纳米SiO2粒子间的连接面积,为增强气凝胶的机械性能提供了可能性;选用小麦淀粉比选用玉米淀粉更易于保持淀粉-SiO2气凝胶的比表面积以及双孔结构,当硅水比(S/W)为1∶4时,以氨水为催化剂,淀粉-SiO2复合气凝胶的比表面积为376.7 m^2/g;疏水改性常压环境干燥制备的淀粉-SiO2气凝胶的热稳定性降至200℃。

Preparation of Starch-SiO2 Composite Aerogels

By preparing starch-SiO2 composite aerogels with atmospheric drying process and obtaining the optimum technological parameters of aerogels,this paper studies the effects on the pore structure,microstructure and thermal stability of the aerogels through BET,SEM and TG-DTA test. The results show that the addition of starch could effectively increase the connection area between SiO2 nanoparticles and provide a possibility for enhancing the mechanical properties of aerogels.Wheat starch is easier to maintain the specific surface area and dual pore structure of starch-SiO2 aerogels than corn starch. When the ratio of silicon to water(S/W) is 1 ∶ 4,the specific surface area is catalyzed by ammonia. The thermal stability of starch-SiO2 aerogels prepared by hydrophobic modified ambient pressure drying is reduced to 376. 7 m^2/g at 200 ℃ .