Effect of ZnO addition on structure,bioactivity, and corrosion protection of mica-fluorapatite glass/glass-ceramic

The bioactivity and technological properties of glass and glass-ceramics make them candidates to be used as a coating on thin-film porous titanium oxide. So, a series of 80% mica + 20% fluorapatite glass with gradual replacement of 0.5, 1.0, 1.5 mol.% of MgO by ZnO were prepared by a traditional melting method. The structure of the prepared samples was characterized using differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), and infrared spectroscopy techniques (FTIR). The gradual substitution of MgO by ZnO decreased the (Tg°C) and (Tc°C) temperatures as DTA analysis indicated. XRD patterns confirmed the crystallization of Na-phlogopite, Na-mica, and foresterite beside fluorapatite as the main crystallized phase, increasing the ZnO content catalyzed the crystallization of willemite, diminished the fluorapatite, and concealed the mica crystallization. FTIR analysis exhibited the characteristic IR features belonging totetrahedral SiO4, BO4, and trigonal BO3 besides essential sharing of phosphate chains. The bioactivity behavior of glass/glass-ceramic samples was examined by utilizing the XRD, FTIR, and SEM techniques after their immersion in simulated body fluid (SBF). The samples provided good mechanical properties by microhardness measurements and good antibacterial behavior to some kinds of bacteria. Electrophoretic deposition of glass and glass-ceramic on the titanium (Ti) surface inhibited its corrosion in SBF. MFZ1G/Ti displayed the highest corrosion resistance among different glass samples, while MFZ3GC presented the most protective coat among the glass-ceramic coat samples.