Air DBD plasma treatment on three-dimensional braided carbon fiber-reinforced PEEK composites for enhancement of in vitro bioactivity

Surface treatment for bio-inert PEEK and its composites is required to broaden their applications in biomedical fields. In this work, a dielectric barrier discharge (DBD) plasma treatment in ambient air was performed on the surface of a three-dimensional braided carbon fiber-reinforced PEEK (C3D/PEEK) composite. The changes in surface chemistry and topography after DBD treatment were examined using water contact angle measurement, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Apatite formation on the DBD-treated C3D/PEEK composite was assessed using SEM after immersion in a simulated body fluid (SBF) to determine its in vitro bioactivity. It was shown that DBD plasma treatment led to a significant decrease in water contact angle, an increase in roughness and the creation of new oxygen related functional groups on C3D/PEEK composite. These changes were found to result in a significant improvement in its in vitro bioactivity. The results presented here clearly indicate that DBD plasma treatment in air is capable of modifying the surface of C3D/PEEK composite such that the treated surface changes from bio-inert to bioactive.