Functionalization of CoCr surfaces with graphene oxide

Abstract

Improvements regarding durable lubrication together with minimized wear are mandatory for obtaining long-term, functioning metallic joint prostheses. For this goal, CoCr surface was functionalized with Graphene Oxide (GO), characterized by FTIR and XPS, and tested at tribocorrosion. Deposition of graphene oxide was carried out by consecutive steps: alkalinization of CoCr; intermediate coupling via 3-aminopropyltriethoxysilane (APTES) which was cured at 45 °C for 24 h; and final assemble of GO layers at 60 °C for 24 h upon exposure with silane-coated CoCr. FTIR displayed C=C band confirming the assembly of GO on silane-coated CoCr surfaces. XPS elucidated reaction between primary amines of APTES and epoxy groups of GO, free -OH groups in APTES and carboxyl groups in GO, and reaction between APTES primary amines and -OH from carboxyl groups of GO. COF values for GO incubated on silane-coated CoCr disks show stationary values near 0.2. CoCr surfaces in as-reception state show higher COF values increasing at longer testing times.