Structural and surface studies on calcium phospho-silicate glass-ceramics containing zinc and iron oxide

Effects of ZnO addition on structural and microstructural properties of glass/glass-ceramic with nominal composition 25SiO2–50CaO–15P2O5–(10 − x) Fe2O3 − x ZnO (where x = 0–5 mol%) have been studied. Glasses were prepared by melt-quench technique and converted into glass-ceramics by controlled heat treatment. The glass-ceramics samples were immersed in bovine serum albumin (BSA) and their surfaces were investigated using Fourier transform infrared spectroscopy (FTIR) and time of flight-secondary ion mass spectrometry (TOF-SIMS). Microstructure of glass-ceramic exhibited a granular microstructure. Calcium phosphate, calcium silicate (Ca3Si2O7), hematite and magnetite phases were observed. Surface morphology of glass-ceramics after immersion in BSA showed the formation of SiOH functional groups. Absorption of BSA took place by interacting with the silanol groups present at the surface. The fraction of non-bridging oxygen decreased with the increase in the amount of ZnO, which led to a decrease in the surface dissolution; thereby decreasing the adhesion of BSA.