Preparation of mesoporous silica ceramics with relatively high strength from industrial wastes by low-toxic aqueous gel-casting

Bulk mesoporous silica ceramics with homogeneous microstructure were prepared in this study using a low-toxic aqueous gel-casting method with industry waste as a raw material. The pore size of the porous silica ceramics prepared was about 30 nm. The solid loading and sintering temperature showed significant influence on the properties of resultant silica porous ceramics, including porosity, pore size, and pore volume, all of which are easily adjusted by changing the loading and temperature parameters. The addition of glutinous rice flour (GRF) increased the porosity and pore volume of the ceramics while maintaining uniform microstructure and nanoscale pore size. Adding 10 wt% GRF in the slurries increased porosity from 47.5% to 55.1% and pore volume from 0.117 cm3/g to 0.141 cm3/g. The highly porous silica ceramics also possessed relatively high mechanical strength of up to 34.96 MPa, suggesting its promising potential application in catalytics, filter industries, and other relevant fields.