Producing porous glass with high alkali resistance - by heat treating mother glass to separate into two phases, acid leaching to remove 2nd phase rich in boron oxide

摘要

Porous glass is produced by using a mother glass containing in wt.% 50-70 SiO2; 0-5 Al2O3; 20-30 B2O3, 3-10 of at least one alkali metal oxide from Na2O, K2O and Li2O; 0-10 ZrO2; 0-10 SnO2; 0-5 P2O5 and 0-5 V2O5. The total of ZrO2 + SnO2 is 1-10 wt.% and the total of P2O5 + V2O5 is 1-5 wt.%. The mother glass is subjected to a phase sepn. by heat treating the glass producing a first phase rich in SiO2 and a second phase rich in B2O3 and alkali metal oxide. The second phase is then leached out of the glass by treatment with an acid solution to produce pores in the residual glass. USE/ADVANTAGE - As adsorption material, molecular sieve for separating gases or liquids and support for catalyst, or immobilised enzyme. The porous glass has high chemical resistance esp. against alkali solns.