Comparison of the Physicochemical Properties of Carboxylic and Phosphonic Acid Self-Assembled Monolayers Created on a Ti-6Al-4V Substrate.

Michal Cichomski,Mariusz Dudek,Andrzej Sikora,Damian Batory,Dorota Anna Kowalczyk,Milena Prowizor

doi:10.3390/ma13225137

Abstract

This study compared the tribological properties in nano- and millinewton load ranges of Ti‑6Al-4V surfaces that were modified using self-assembled monolayers (SAMs) of carboxylic and phosphonic acids. The effectiveness of the creation of SAMs with the use of the liquid phase deposition (LPD) technique was monitored by the contact angle measurement, the surface free energy (SFE) calculation, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) measurements. The obtained results indicated that more stable and well-ordered layers, which were characterized by the lowest values of the coefficient of friction, adhesion, and wear rate, were obtained using phosphonic acid as a surface modifier. Based on the obtained results, it was found that the Ti-6Al-4V alloy modified by phosphonic acid would be the most advantageous for practical applications, especially in micro- and nanoelectromechanical systems (MEMS/NEMS).

Highlights

Titanium and its alloys are widely used in various important fields of industry in which their physicochemical and mechanical properties play a very important role [1,2]
Based on the measured contact angle, the optimal deposition time was selected for different solution concentrations
The presented results of this investigation of phosphonate and carboxylate self-assembled monolayers (SAMs) created on the oxidized surface of Ti-6Al-4V substrates show that due to the appropriate selection of parameters of the liquid phase deposition (LPD) process, hydrophobic surfaces can be obtained

Summary

Introduction

Titanium and its alloys are widely used in various important fields of industry in which their physicochemical and mechanical properties play a very important role [1,2]. The major drawback to the use of Ti-6Al-4V is the presence of toxic elements, such as aluminum (Al) and vanadium (V). These ions are released to the surrounding tissues when the alloy is implanted into the human body [8,9,10].

Methods

Results

Conclusion