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

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, N₂(C-B), N₂⁺ (B-X), N₂(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.