Fabricating PTFE nanocomposites via in situ filling of hydroxyapatite nanowires and their tribological performance

Abstract

Excellent tribological performance and biocompatibility are required for the biomaterials that can be used for artificial acetabular cups. Hydroxyapatite nanowires, herein, were in situ filled into PTFE, and the resulting PTFE nanocomposites presented a high dispersion degree and a reliable interface adhesion. There were significant improvements in stiffness, heat-resistant and hydrophobic capabilities observed. It was observed that there were drastically decreased coefficients of friction and volume wear rates, which were determined by a sliding friction against a high-speed steel ring in the presence of simulated body fluid, and less and shallower plough furrows on the worn surfaces of the in situ fabricated nanocomposite specimens. The enhancements in tribological performance might be attributed to the one-dimensioned hydroxyapatite nanowires with the characteristics of both nano- and micro-sized materials and outstanding properties in mechanics, thermology, tribology. And the in situ fabrication method contributed to a reliable stress transfer between the matrix and the nanofillers, and led to a marked enhancement in stiffness, wear resistance and friction reduction of the nanocomposites fabricated with respect to the pristine PTFE even at a mass fraction of as low as 0.5%. The fabrication method and the resulting PTFE nanocomposites may suggest a way to a promising application in acetabular cups or other artificial joints/human tissues. • PTFE composites are fabricated via in situ filling of hydroxyapatite nanowires. • The nanofillers present a high dispersity and a reliable interface combination. • Mechanical, thermal and tribological properties are improved by in situ filling. • In situ filling contributes to dispersion, interfacial adhesion, and stress transfer. • Filler characteristics and fabrication method impart enhanced tribological performance.