The Effect of Pretreated Titanium Surface Topography on the Properties of Electrophoretically Deposited Chitosan Coatings from Ethanol-Based Suspensions

This study investigated the influence of surface preparation methods on the microstructure, chemical composition, wettability, corrosion resistance, and adhesion of chitosan coatings on titanium substrates for biomedical applications. Titanium samples were subjected to grinding with abrasive papers of gradations #800, #1200, and #2000, electrochemical anodization, and etching. Surface characterization revealed that the etched samples presented the highest roughness, with Sa values reaching 0.75 mu m, significantly surpassing the values of the ground samples. The electrophoretically deposited chitosan coatings from ethanol-based suspensions were relatively thin (similar to 1 mu m). Except for the sample after anodization, all the samples were hydrophilic. Compared with the anodized samples, the corrosion tests revealed the lowest corrosion current density among the pretreated samples for the ground and etched substrates (several hundred nA/cm(2)). The deposition of chitosan coatings contributed to a decrease in corrosion resistance, but the measured values of the corrosion parameters were satisfactory. Adhesion tests revealed that coatings on etched surfaces achieved the highest adhesion class (class 0), whereas those on electrochemically oxidized surfaces were class 4, highlighting the importance of surface preparation for optimal coating performance. All tested surfaces initiated the precipitation of calcium- and phosphorus-based salts essential for osteointegration. These findings suggest that etching titanium substrates with chitosan coatings is promising for enhancing the biological performance of titanium implants. (c) The Minerals, Metals & Materials Society and ASM International 2025