Preparation and Characterization of Alkylphosphonic Acid Self- Assembled Monolayers on Titanium Alloy by Chemisorption and Electrochemical Deposition

ABSTRACT: Ti-6Al-4V alloy is the most commonly used alloy for dental and orthopedic implants. In order to improve osseointegration, different surface modification methods are usually employed, including self-assembled monolayers (SAMs). This study presents an investigation of both active (electro-assisted) and passive (adsorption) approaches for the modification of Ti-6Al-4V using alkylphosphonic acid. The monolayers were characterized by cyclic voltammetry, double-layer capacitance, contact angle measurements, X-ray photo-electron spectroscopy, polarization modulation infrared reflec-tion adsorption spectroscopy, electrochemical impedance spec-troscopy, and corrosion potentiodynamic polarization measure-ments. It is shown that the electrochemically assisted monolayers, which are assembled faster, exhibit better control over surface properties, a superior degree of order, and a somewhat higher packing density. The electrosorbed SAMs also exhibit better blockage of electron transfer across the interfac