Comparative Study of the Surface Cleaning for Ar-/He-Based Plasma Jets at Atmospheric Pressure

Abstract

In this study, an atmospheric-pressure He/O 2 or Ar/O 2 plasma jet is generated by a specially designed equipment with two coaxial quartz tubes and double power electrodes to remove lubricants from the surfaces of metals. The experimental results indicate that the cleaning performance is much better in the Ar/O 2 plasma jet than in the He/O 2 plasma jet under the same input power and O 2 mixing ratio. It is found that more electron, more atomic oxygen, and more metastable Ar atoms generated in the Ar/O 2 plasma jet result in better cleaning performance. In the He/O 2 plasma jet or the Ar/O 2 plasma jet, there exists an optimum O 2 mixing ratio for a certain input power, at which the desirable cleaning performance can be received. And the highest removing rate is 1259.8 ng/s when the 2.1% O 2 in the Ar plasma jet at an input power of 6 W. It is considered that atomic oxygen can be generated most efficiently under this optimum O 2 mixing ratio.

Comparative study of the Ar and He atmospheric pressure plasmas on E-cadherin protein regulation for plasma-mediated transdermal drug delivery

“…Shao et al elucidated that argon is relatively easier to ionize than helium under the same operating conditions because the ionization threshold energy of argon (15.76 eV) is lower than that of helium (24.59 eV) [26]. In addition to the results of Jin et al, our data present that ArP has stronger discharge than HeP under the same applied voltage and flow conditions [27]. The plasma density is higher in Ar discharge than He, which is in accordance with the simulation results of other studies reporting that the electron density of ArP is twice as high as that of HeP [28,29].…”

Highly efficient synthesis of [60]fullerene oxides by plasma jet

“…Two additional emission peaks, which were assigned to the reactive atomic oxygen species O* (777.2 nm, 3p 5 P-3s 5 S) and O* (844.6 nm, 3p 3 P-3s 3 S), were detected in the Ar/O 2 APNPJ [39][40][41][42]. The generation of the reactive oxygen species as well as the production of C 60 O n are shown in equations (3.1)−(3.5) [43][44][45][46]. Firstly, the plasma jet initiated the reaction and produced active species including activated Ar*, electrons and so on.…”

Characteristics of the plasma sheath in helium discharge within dielectric tubes

“…A steep gradient of the electric field near the tube wall presents for the three cases, indicating the formation of a plasma sheath near the tube wall. The influence of the O 2 addition on the n e can be explained as follows: because of the low ionization energy (13.6 eV) required for O 2 molecules compared to He atoms and He metastable [57], the direct ionization by the collisions between the energized electrons and O 2 molecules and the Penning ionization between He metastable and O 2 molecules contribute to the total ionization processes in the He/O 2 mixture discharge [58,59]. Therefore, a small amount of O 2 gas increases the n , e which is observed in the head of the plasma volume where the gas ionization processes take place.…”