In vitro characterisation and microstructure of B_2O_3/P_2O_5 doped bioactive spodumene glass-ceramics

摘要

Glasses with compositions of (100-X-Y)Li_2O.Al_2O_3.4SiO_2+XB_2O_3+YP_2O_5 where X velence 0-2 centre dot 5 and Y velence 0-10 (wt-percent) were melted in a platinum crucible at 1500 deg C with air as the furnace atmosphere. The green compact pellets were prepared and fired at 500 deg C. The samples were sintered in air atmosphere at selected temperatures in the range of 750-900 deg C for up to 20 h. It has been found that the addition of B_2O_3 and P_2O_5 has a remarkable effect on the amount of beta spodumene (beta-S), relative to high quartz solid solution (h-QSS). The glass ceramics that contain appropriate amounts of B_2O_3 and P_2O_5 promise good sinterability at temperature as low as 850 deg C. There were two major types of phase transformation in the present investigation: crystallisation of the present glass to a metastable h-QSS and subsequent transformation from h-QSS to a stable beta-S. In vitro test revealed that the spodumene glass ceramic is much more durable in human body fluid. It is further observed that the addition of B_2O_3 and P_2O_5 enhanced the chemical durability of glass ceramics.