타이타늄의 양극산화 공정: PDMS 수지 보조 양극산화법

초록

Anodization is an electrochemical surface treatment process widely used to fabricate oxide films on titanium (Ti), offering enhanced corrosion resistance, biocompatibility, and surface functionality. Porous anodic oxide layers formed through this method have shown great potential in applications such as biomedical implants, sensors, and catalyst supports due to their high surface area and tunable nanostructure. Conventional anodization of Ti typically produces nanotubular oxide films using fluoride-containing electrolytes. However, these films often suffer from poor adhesion and low mechanical durability due to the formation of a fluoride-rich interfacial layer. While plasma electrolytic oxidation (PEO) can yield more durable oxide films, it requires high-voltage and high-current conditions, resulting in significant energy consumption and limited structural control. In this study, we introduce a novel polydimethylsiloxane (PDMS)-assisted anodization method that enables the formation of a uniform porous oxide film under low-energy conditions without the use of fluoride-based electrolytes. Upon applying sufficient voltage, the PDMS resin layer becomes hydrophilic, allowing water molecules to permeate. Oxygen evolution reactions (OER) occur at the electrode surface, generating oxygen gas that accumulates within the PDMS layer. This trapped gas promotes continuous dielectric breakdown, leading to the formation of a highly uniform porous oxide structure. By precisely adjusting the applied voltage and reaction time, we successfully controlled the film thickness and pore size. The resulting oxide film exhibited a superhydrophilic surface with a contact angle of 7°. While the nanotubular oxide film formed through conventional anodization delaminated too quickly to quantify adhesion strength, the PDMS-assisted sample exhibited significantly improved adhesion, withstanding up to 0.45 N in scratch testing.