Abstract
Friction and wear properties play an important role in the long-term in vivo performance of load-bearing bioceramic implants. In this study, the friction and wear behaviors of hydroxyapatite (HA) reinforced with reduced graphene oxide (rGO) and rGO + carbon nanotube (CNT) hybrids were studied by ball-on-disk tests to understand the effects of nanocarbon content and morphology on the composites’ tribological behaviors. The intact and worn surfaces were characterized by optical microscopy, nanoindentation, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Raman spectroscopy. We found that the incorporation of rGO and rGO + CNT hybrids in HA bioceramic both improved the friction and wear behaviors, and the highest wear resistance was achieved by employing 1 wt% rGO and 1 wt% CNT as reinforcements. The major reinforcing mechanism was the formation of carbonaceous films between the composite surfaces and counterbody, which served as solid lubrication films that resulted in a lower coefficient of friction, higher hardness, and increased hardness/modulus ratio. Importantly, CNT addition facilitated the uniform distribution of the reinforcements in the HA matrix and the pinning effects of CNT enhanced the connection between rGO and HA.
Highlights
The aging of the world’s population creates an increasing demand for bone repair and regeneration, with over four million operations annually (Amini et al, 2012; Turnbull et al, 2018)
We report the preparation of reduced graphene oxide (rGO) and rGO/carbon nanotube (CNT) hybrids reinforced HA composites, and rationalize their structural, mechanical, and tribological properties
Compared with pure HA, the wear track widths of the composites were reduced at higher total nanocarbon content, and the narrowest value was obtained in 1 wt% rGO and 1 wt% CNTreinforced composites
Summary
The aging of the world’s population creates an increasing demand for bone repair and regeneration, with over four million operations annually (Amini et al, 2012; Turnbull et al, 2018). While the use of autografts remains the gold standard treatment, they have very limited availability and can cause donor site morbidity. Allografts and xenografts, albeit with higher availability, pose risks such as disease transmission and detrimental immune responses (Martin and Bettencourt, 2018). Bioceramics are among the most widely used materials for hard tissue repair. Among the diverse forms of bioceramics, hydroxyapatite (Ca10(PO4)6(OH), HA) has attracted significant attention because it is the main mineral component in bones and teeth of vertebrates; the biocompatibility, bioactivity, and osteoconductivity of HA have led to its extensive applications
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
