The effect of ZnO nanoparticles on the mechanical, tribological and antibacterial properties of ultra-high molecular weight polyethylene

In this study, the response of different filler loadings (5-20 wt%) of zinc oxide nanoparticles reinforced ultra-high molecular weight polyethylene on the mechanical, tribological and antibacterial performances were attempted. The compression, tensile and micro-hardness properties of the nano-zinc oxide/ultra-high molecular weight polyethylene composites were studied. The tribological properties were investigated using DUCOM pin-on-disc tester with variable applied loads (5-35 N) and sliding speeds (0.209 m/s and 0.419 m/s) against 1200 grit size silicon carbide abrasive paper under dry sliding conditions. The worn surfaces and transfer films of the composites were observed using the scanning electron microscopy. Experimental results show that reinforcing ultra-high molecular weight polyethylene with zinc oxide nanoparticles would improve certain mechanical and tribological properties. Wear performance was enhanced with maximum wear resistance found at 10 wt% nano-zinc oxide/ultra-high molecular weight polyethylene composite. The average coefficient of friction of ultra-high molecular weight polyethylene shows a decrease after reinforcement with zinc oxide nanoparticles. Upon zinc oxide nanoparticles reinforcement, the worn surface shows reduced severity of wear. The nano-zinc oxide/ultra-high molecular weight polyethylene composite imparts antibacterial activity against Escherichia coli and Staphylococcus aureus.