Wettability of nanotubular titania layers for biomedical applications developed by electrochemical anodization

Abstract

The titania nanotubes (TNT) were synthesis on Ti6Al4V alloy planar surfaces with different initial preparation: polished, turned, acid etched, and SLA (sand blasted with large grits and acid etched), by electrochemical anodization performed in phosphate/fluoride based electrolyte, using anodization potentials of 20 V or 24 V. The morphology of developed layers was investigated by scanning electron microscopy (SEM) and consists in highly ordered, self-arranged TiO2 nanotubes of 25-110 nm in diameter. The initial and modified surfaces’ wettability was evaluated by static contact angle method and drop shape analysis. The contact angle measured on modified surfaces with TNT developed on polished surfaces is 70° showing moderate hydrophilic properties, while the contact angle measured on TNT layers developed on micro rough surfaces (turned, acid etched, SLA) is lower, showing the enhancement of surfaces wettability. Turned surfaces covered with TNT exhibits a contact angle of 60°, on SLA surfaces modified with TNT layers contact angle is 47°, while the best wettability, demonstrated by a contact angle of 35°, is showed by acid etched surfaces covered with TNT layers.