Effect of suspension medium on the characteristics of electrophoretically deposited bioactive glass coatings on titanium substrate

Bioactive glasses (BGs) have been extensively investigated for use in medical applications due to their excellent biocompatibility and bioactivity. In this work, synthesized BG nanoparticles were deposited on titanium substrate by electrophoretic deposition (EPD) method. Suspensions of BG nanoparticles were prepared in different solvents (methanol, ethanol, isopropanol and butanol) using triethanolamine (TEA) as dispersing additive. Adsorption of TEA on BG particles increased with molecular size of alcohols; so the optimum concentration of TEA obtained at less amounts in larger molecular size alcohols: 0.4, 0.2 and 0.13Vol% for ethanol, isopropanol and butanol based suspensions, respectively. Suspension medium had the great effect on the microstructure of obtained coatings. Microstructures with mostly coarse, mixed (fine and coarse) and fine particles were obtained using ethanol, isopropanol and butanol based suspensions, respectively. Among the suspensions, the isopropanol based one with optimum TEA amount had the highest stability. Also the coatings obtained from isopropanol based suspension had the relatively high sinterability and roughness. So, the isopropanol based coating was chosen as the optimum one. The amorphous structure of optimum BG coating was survived even after sintering at 800 degrees C. The optimum coating showed good fibroblast cell adhesion and antibacterial activity against Escherchia coli and Staphylococcus aureus bacteria.