Fabrication of HAp/rGO nanocomposite coating on PEEK: Tribological performance study

Abstract

Polyetheretheretherketone (PEEK) is a prominent alternative material in medical applications because of its lower stress shielding impact than metal. Friction and wear characteristics have a large impact on the long-term in vivo performance of load-bearing implants. As a result, orthopaedic polymer implants have been subjected to a myriad of surface changes to increase their biofunctionality. In this study, wear resistant coatings, including hydroxyapatite (HAp) and reduced graphene oxide (rGO) as HAp/rGo, rGo/HAp and HAp+rGO nano composites were applied to the polyetheretherketone (PEEK) sample through dip coating method. The characterization of various coating combinations and patterns was accomplished by FESEM, XRD, AFM, and FT-IR. It was observed that the inclusion of rGO with HAp enhanced the friction and wear behaviour, with the HAp+rGO composition achieving the best wear resistance. In addition, carbonaceous films formed between the composite surfaces and counter body operated as solid lubricating films, resulting in a drop in the coefficient of friction (COF) from to 0.23 r min−1 on the coating and even helps to increase hydrophobicity state of the coating. Nevertheless, because rGO functions as an interstitial bonding agent between PEEK and HAp, bond strength increases, with the HAp+rGO combination having the highest bond strength of 35 MPa.