Ultra-High Molecular Weight Polyethylene Modifications Produced by Carbon Nanotubes and Fe₂O₃ Nanoparticles

Thin sheets of ultra-high molecular weight polyethylene (UHMWPE), both in pristine form and containing carbon nanotubes (CNTs) or Fe₂O₃ nanoparticles (NPs) at different concentrations, were prepared. The CNT and Fe₂O₃ NP weight percentages used ranged from 0.01% to 1%. The presence of CNTs and Fe₂O₃ NPs in UHMWPE was confirmed by transmission and scanning electron microscopy and by energy dispersive X-ray spectroscopy analysis (EDS). The effects of the embedded nanostructures on the UHMWPE samples were studied using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and UV-Vis absorption spectroscopy. The ATR-FTIR spectra show the characteristic features of the UHMWPE, CNTs, and Fe₂O₃. Concerning the optical properties, regardless of the type of embedded nanostructures, an increase in the optical absorption was observed. The allowed direct optical energy gap value was determined from the optical absorption spectra: in both cases, it decreases with increasing CNT or Fe₂O₃ NP concentrations. The obtained results will be presented and discussed.