Nanosteel synthesis via arc discharge: media and current effects

Abstract

Size, purity, yield, and morphology of arc-synthesized nanosteel particles are altered by the employed currents (50, 80, and 100 A/cm²), as well as the media [nitrogen, open air, ethylene glycol, and distilled water saturated with polyvinylpyrrolidone (PVP)]. Nanoparticles (Nps) produced at 80 A/cm² in distilled water, PVP-saturated distilled water, and ethylene glycol are on average five times smaller than those synthesized in nitrogen and open air. This is attributed to the capping as well as stabilizing effects of the liquid media. Changing current from 50 to 80 A/cm² results in a decrease of Nps sizes in the liquid media, and a size increase in the gaseous media, which suffer from the lack of grain growth and particle aggregation prohibitor agents. SEM images and XRD profiles show the purest nanosteel particles formed in nitrogen, with an average size of 29 nm at 50 A/cm². Nps with relatively smaller size (7 nm) are obtained in distilled water at 100 A/cm², as a mixture of nanosteel and nano Fe₃O₄ particles. Yet, comparatively the highest amounts of the latter are formed in the open air at 80 A/cm².