Structural refinement and antimicrobial activity of aluminum oxide nanoparticles

Abstract

The study aimed to prepare Al₂O₃ nanoparticles (NPs) from aluminum wastes (originate from aluminum workshops as waste) and tested its antimicrobial activity against bacteria (Gram-negative): Escherichia coli ATCC25922, Salmonella Typhimurium ATCC14028, Pseudomonas aeruginosa ATCC27853, Alcaligenes aquatilis and bacteria (Gram-positive): Staphylococcus aureus ATCCBAA977 and Streptococcacea pneumonia ATCC49619, types of Fungal Aspergillus niger, Aspergillus flavus and Penicillium sp. The nanomaterial prepared were confirmed using X-ray diffraction (XRD), Scan electron microscope (SEM) with Energy dispersive X-ray analysis (EDAX) techniques. The structural refinement of this material has been achieved by the Rietveld method. The shape, the cell parameters and the atomic positions were deduced for each allotropy form appearing at different calcination temperature (700–1300 °C) with particle size less than 100 nm. Results obtained by XRD denoted that alumina that obtained is crystallite nano-particles, with size ranged from 15 nm at 90 °C to 50 nm at 1300 °C, that confirms that calcination temperature direct influences the crystallite growth. EDX analyses show only the presence of two peaks for aluminum and oxygen. The aluminum NPs had antimicrobial activities. The diameter of the inhibitory zone shows the sensitivity of the microorganism to Al₂O₃ NPs especially at 30 % dimethyl sulfoxide (DMSO). Furthermore, the inhibitory effect of Al₂O₃ NPs increases with decreasing of the DMSO concentration.