Characteristic and Application Study of Cold Atmospheric-Pressure Nitrogen Plasma Jet

Abstract

Atmospheric-pressure discharge plasma is a promising tool for many applications due to its enhanced plasma chemistry. In this paper, a low-temperature atmospheric-pressure nitrogen plasma jet generated by bare metal electrode's discharge is reported. The typical electrical and optical characteristics of the atmospheric-pressure plasma jet (APPJ) are studied. Optical emission spectrum shows that excited OH, NO, N 2 (C-B), N 2 + (B-X), N 2 (B-A), and O emissions are produced by the plasma jet. When the applied voltage is 2.5 kV, the vibrational and rotational temperatures of the APPJ are, respectively, 2275 and 325 ± 5 K. Hydrophilic treatment of the superhydrophobic aluminum surface is also presented, and the results show that the wettability of the APPJ-treated areas is obviously improved, which was mainly due to the slight morphological changes and the incorporation of oxygen-containing functional groups. A pumpless antigravity water transport on APPJ-induced wettability contrast patterning surface is also presented to show the potential applications of the APPJ hydrophilic treatment of metals. These results demonstrate the application prospects of bare electrode's discharge plasma jet, especially in metal-based smart surface fabrications.