DEVELOPMENT OF ALKALI-RESISTANT POROUS GLASS BASED ON (69-x)SiO_2-25B_2O_3-6Na_2O-xZrSiO_4 SYSTEM

摘要

Alkali resistant porous glass has been developed by making additions of ZrO_2 in form of zircon (ZrSiO_4) to the sodium borosilicate glass system SiO_2-B_2O_3-Na_2O. Differential thermal analysis (DTA) was carried out to determine the appropriate heat-treatment. Additions of ZrSiO_4 reduced the crystallisation tendency and inhibit coarsening process during heat-treatment. After leaching, a silica-rich skeleton with an interconnected pore structure and a uniform pore distribution was observed. Pore characterisation was carried out using mercury porosimetry. The mean pore diameter increased with increasing heat-treatment dwell time. The total pore surface area increased with addition of ZrSiO_4. Additions of ZrSiO_4 increased the alkali resistance of the porous glass 3-4 times.