添加环氧丙烷法常压干燥制备ZrO_2气凝胶  

Synthesis of Zirconia Aerogels by Ambient Pressure Drying with Propylene Oxide Addition

作　　者：郭兴忠[1] 颜立清[1] 杨辉[1] 李建[1] 李超宇[1] 蔡晓波[1] 

机构地区：[1]浙江大学材料科学与工程学系,杭州310027

出　　处：《物理化学学报》2011年第10期2478-2484,共7页Acta Physico-Chimica Sinica

基　　金：浙江省重点创新团队项目(2009R50010)资助~~

摘　　要：以无机锆盐硝酸氧锆(ZrO(NO_3)_2·5H_2O)为前驱体,1,2-环氧丙烷(PO)为凝胶促进剂,甲酰胺(FA)为干燥控制化学添加剂(DCCA),采用溶胶-凝胶法并通过常压干燥制备了轻质二氧化锆(ZrO_2)气凝胶,利用差热分析(DTA)、扫描电镜(SEM)、N_2吸附/脱附等测试技术对所制得的ZrO_2气凝胶进行了表征.结果表明:添加环氧丙烷常压干燥制得的ZrO_2气凝胶具有纳米尺寸的多孔网络结构,表观密度可低至202.08 kg·m^(-3),比表面积可高达645.0m^2·g^(-1),与超临界干燥效果相当.环氧丙烷因其环氧原子的强亲核性和不可逆的开环反应,可促进凝胶化,并通过环氧丙烷的量控制反应过程和凝胶状念.ZrO2 aerogels were successfully synthesized by the sol-gel process and ambient pressure drying using ZrO（NO3）2.5H2O as a precursor, 1,2-propylene oxide （PO） as a gelation agent, and formamide （FA） as a drying control chemical additive （DCCA）. The prepared zirconia aerogel samples were characterized using differential thermal analysis （DTA）, scanning electron microscopy （SEM）, and nitrogen adsorption/desorption analysis. The results showed that the zirconia aerogels prepared by the propylene oxide addition method had a nanoscale porous network structure, as well as supercritical dried ones, with a low bulk density （202.08 kg. m^-3） and a high surface area （645.0 m2. g^-1）. Propylene oxide can induce gelation through its nucleophilic property and its irreversible ring-opening reaction, and thus the sol-gel process and the state of gel can be controlled.

关 键 词：气凝胶:ZrO2:常压干燥 环氧丙烷:溶胶-凝胶 

分 类 号：O614.412[理学—无机化学]