| Aerogel materials with nano-porous, high porosity, high surface area, low-density,low thermal conductivity could be applied widely in the field of high temperaturethermal protection, catalytic science, optics, acoustics, microelectronics and so on.In this study, zirconium oxychloride was used as raw material, by means of sol-geltechnology and supercritical CO2drying process, we could prepare zirconia aerogels, aswell as silicon-doped zirconium composite aerogels. The micro-structure and somethermal properties were analyzed by SEM, BET, TGD/TA, XRD, FT-IRAfter scanning different reaction condition, we got the optimized formula: we usedZrOCl2as Zr source, PO (propane oxide) as “proton scavenger”(which could adjust theconcentration of proton in the reaction solvent), and control the quantity of somereactants as follow: the mol ratio of PO: Zr (or the total mol quantity of Zr and Si whenwe used Si as hybrid) was2~5; the percent of ZrO2(or the total percent of ZrO2andSiO2when we used Si as hybrid) was2~5%. Reactions were performed in the solvent ofethanol and water (the ratio of volume was1or little higher than1), Zr aerogels withlow shrinking measure, low density and high surface area could be achieved. And wefound that when Si was used as hybrid, the temperature of phase transfer of Zr aerogelfrom amorphism to crystal increased from600oC to800oC, that is to say, the thermalstability in high temperature of Zr aerogels could be improved highly by introducing Si.When the ceramic fibers were used as enhanced materials, we could prepare thecomposite aerogels with good themal and mechanical properties.Test results show that mullite fiber reinforced zirconium-silicon aerogelcomposited with rutile TiO2(which could block infred radiation) is a kind ofmesoporous material with high surface area (up to600m2/g and above), large porevolume (up to2.63cm3/g), uniform pore size distribution, and high temperature thermalstability, and it has the great potential in the application of industry. |
PDF Full Text Request