作者：ZHAO Huizhong;HU Shoutian;WANG Houzhi;

作者单位：Center of Nanomaterials and Technology, Wuhan University of Science and Technology (WUST), Wuhan, 430081, China

刊名：China's Refractories

ISSN：1004-4493

出版年：2003-01-05

卷：12

期：4

起页：20

止页：24

分类号：TQ175

语种：英文

关键词：Nanosized mullite;Sol-Gel;Supercritical fluid drying;Synthesis;Calcinations;

内容简介

Nanoscale mullite powder were synthesized via Sol-gel-SCFD and middle temperature treatment by using AIP (aluminum-isopropoxde) and TEOS (tetraethyl orthosilicate) as starting materials. Both of the binary aerogel of alumina-silica and calcined nanoscale materials were investigated by using TG-DSC (thermogravimetry-differential scanning calorimeter), TEM (transmission electron microscope), XRD (X-Ray diffractometer) and specific surface area and porosimetry. TG-DSC indicated the removal of most of the volatiles, i.e. 15.98 percent up to about 700 deg C, and in the DSC curve, existence of two exothermic peak at about 445 deg C and 1015 deg C may be due to the crystallization of Si-O-Al-O in diphasic gels and mullitization and a small endothermic peak at about 805 deg C indicated the decomposition of structural water molecules. On the colligation of the results of TG-DSC, XRD and TEM, the beginning temperature of mullitization of Al_2O_3-SiO_2 aerogel system can be confirmed at about 1015 deg C. XRD results also showed the formation of mullite at the range 1100 approx 1200 deg C. TEM and surface area and porosimetry results showed that the nanosized mullite were calcinated at 1100 and 1200 deg C exhibited size 30 nm and 50 nm, specific surface area 138.91 m~2/g and 95.81 m~2/g.