Synthesis of Pyrex-type porous glass made with calcium carbonate as pore forming material

摘要

Pellets and substrates made from powders of Pyrex-type and soda lime glasses and alkaline earth carbonates were prepared and sintered in the 625-850C range. Powder preparation, sintering temperature, alkaline earth carbonate concentration, acid leaching of alkaline earth carbonate after sintering and effects of time on pellets' integrities after sintering were studied. Densities and porosities of pellets after acid leaching were estimated from pellet's dimensions and weight. CaCO3 behaves in a different way from SrCO3 and BaCO3. Pellets made with CaCO3 break after sintering for the majority of sintering temperatures studied. A mechanism for pellets' breakage based on XRD studies is proposed and discussed. A procedure based on the new mechanism was implemented successfully to prevent breakage after sintering.