1994 Volume 102 Issue 1190 Pages 966-971
Porous silica ceramics with homogeneous pore distribution were prepared by the hydrothermal hot-pressing of silica gels. The recovered porous ceramics had high mechanical strengths with large pore volumes. The ceramics prepared at 300°C and 20MPa for 1h with 17.2mass% water showed the following properties; high compressive strength (60MPa), low bulk density (0.68g/cm3), large pore volume (0.98cm3/g), and uniform pore distribution with average pore size of 65nm. The average pore diameter of the ceramics was controlled from 25 to 100nm by selecting hydrothermal hot-pressing conditions and starting silica gels. The formation mechanism of large pores in the silica ceramics could be elucidated by capillary effects.
