Al nanoparticles: Impact of media and current on the arc fabrication

To optimize the arc fabrication of aluminum nanoparticles (Al Nps), six diverse media were probed including ethylene glycol (EG), distilled water, liquid nitrogen, gaseous nitrogen, sunflower oil, and tap water (all free of any surfactant or stabilizer). These were investigated at three different currents: 50, 100 and 150 A/cm 2. EG at 50 A/cm 2 provides the best recipe for the arc fabrication, giving the relatively purest, most dispersed and the smallest size Al Nps (26.6 nm), with the highest yield (91.5 %). Regardless of the medium used, the SEM analyses show that the size increases of Al Nps are directly proportional to the current density employed. The observed sizes for Al Nps in EG (at three different currents/A cm - 2) are 26.6 nm (50), 64.9 nm (100), and 72.5 nm (150). Also, regardless of the current employed, the SEM analyses show different Al Nps size distributions, depending on the medium nature. The XRD extracted average sizes of the arc fabricated Al Nps show reasonable linear correlations with their corresponding elemental weight% or atomic%, acquired through energy-dispersive X-ray spectroscopy (EDX). High quantities of separable industrially significant nanoAl oxides (γ-Al 2O 3, Al(OH) 3) are fabricated along with Al Nps in tap water. In EG medium, TGA revealed only ∼7% weight loss, indicating thermal stability of the fabricated Al Nps.