Synchronized Improvements in the Protective and Bioactive Properties of Plasma-Electrolyzed Layers via Cellulose Microcrystalline

This study reports synchronized improvements in the protective and bioactive properties of Ti-6Al-4V alloy through the formation of titania-based inorganic layers by considering the role of cellulose microcrystalline (CMC) additive into account. Acetate-phosphate-based electrolyte with cellulose CMC is formulated for the first time to modify the porous structure of the oxide layers made via plasma electrolysis of Ti-6Al-4V alloy. The presence of CMC (0, 1, 2, 3 g/L) changed the characteristics of plasma discharges where porous oxide layers with different pore sizes and surface roughness were obtained. A rough oxide layer with large pores was found in the 3 g/L CMC, while a slightly smoother oxide layer with smaller pores was obtained in the case of 2 g/L CMC. The -OH groups in CMC would facilitate the formation of an adsorption layer on the substrate surface, affecting the sparking behavior during plasma electrolysis (PE). Due to a synergy between controlled microstructure, surface roughness, and the insertion of bioactive phases, the coated samples in CMC-containing electrolytes displayed protective and bioactive properties simultaneously. Based on the obtained results, the samples coated in CMC-containing electrolytes can be used as safe implants to replace missing teeth in dental applications.