Synthesis, Characterization and Bactericide Properties of Al₂O₃ Nanoparticles and Al₂O₃-PAN Membranes for Alternative Water Disinfection Methods

Abstract

As the global populations grow, water demand and pollution of water resources will increase. As a consequence, water borne disease outbreaks are on the rise and current disinfection methods have been shown to be ineffective in inactivating all pathogens during water treatment. Aluminum oxide nanoparticles (Al₂O₃ NPs) have been shown to poses antimicrobial properties. Also, Al₂O₃ has high thermal and chemical stability, which makes these NPs an excellent candidate for water treatment applications. Thus, the objective of this work is to assess the bactericidal properties of Al₂O₃ NPs synthesized using a polyol-based process in presence of polyvinylpyrrolidone (PVP). For practical applications nanoparticles must be immobilized in a medium to ensure that particles are not dispersed into the treated water. For this reason, synthesized nanoparticles were dispersed in electrospun polyacrylonitrile (PAN) membranes to also evaluate the bacterial removal capacity. X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) analysis suggests that synthesized nanoparticles are γ-Al₂O₃ after annealing at 800ºC for 6 hours. Scanning Electron Microscopy (SEM) characterization was used to determine the morphology and size of synthesized nanoparticles. Composite electrospun membranes were also characterized by XRD, FT-IR, and SEM. The bactericide activity of the synthesized γ-Al₂O₃ NPs and commercially available Al₂O₃ particles was evaluated by the disc diffusion method against E. coli bacteria. Also, Al₂O₃-PAN composite electrospun membranes bacterial filtration capacity was tested. Both synthesized and industrially produced particles exhibited antibacterial activity against E. coli, but polyol-based synthesized nanoparticles demonstrated better bactericide properties. The bacterial removal capacity of PAN and PAN/Al₂O₃ fibers was comparable to that of paper filters.