The Effect of Oxygen Admixture with Argon Discharges on the Impact Parameters of Atmospheric Pressure Plasma Jet Characteristics

Abstract

Dry argon (Ar) discharge and wet oxygen/argon (O2/Ar) admixture discharge for alternating current atmospheric pressure plasma jets (APPJs) were studied for Ar discharges with flow rates ranging from 0.2 to 4 slm and for O2/Ar discharges with different O2 ratios and flow rates ranging from 2.5 to 15 mslm. The voltage–current waveform signals of APPJ discharge, gas flow rate, photo-imaging of the plasma jet length and width, discharge plasma power, axial temperature distribution, optical emission spectra, and irradiance were investigated. Different behavior for varying oxygen content in the admixture discharge was observed. The temperature recognizably decreased, axially, far away from the nozzle of the jet as the flow rate of dry argon decreased. Similar behavior was observed for wet argon but with a lower temperature than for dry argon. The optical emission spectra and the dose rate of irradiance of a plasma jet discharge were investigated as a function of plasma jet length, for dry and wet Ar discharges, to determine the data compatible with the International Commission on Non-Ionizing Radiation Protection (ICNIRP) data for irradiance exposure limits of the skin, which are suitable for the disinfection of microbes on the skin without harmful effects, equivalent to 30 μJ/mm2.

Compared discharge characteristics and film modifications of atmospheric pressure plasma jets with two different electrode geometries

“…The discharge waveforms were displayed and recorded by a digital oscilloscope (TDS2024C; Tektronix Inc.). The Lissajous plot method was used to measure the dissipated power with a capacitance of 10 nF, and the dissipated power was calculated according to the following equation: [19]…”

“…The most common ones include single-rod electrode, [11,12,15,16] rod-ring (or needle-ring), [4,6,10,17] singlering, [18] and double-ring. [5,7,8,19] APPJ devices, all of which have been used by researchers for surface modification of polymer films. For example, Chen et al used a doublering APPJ device to enhance the surface electrical strength of epoxy resin samples by ionizing a mixture of He/CF 4 gas.…”

Effect of argon cold plasma composition on orthodontic bonding—new insights into input parameters and protocols

“…Reuter et al [19] found an inverse correlation of bullet velocity and oxygen content of CAP. Asghar et al [2] and Bekeschus et al [3] reported that the admixture of oxygen lowered the discharge plasma power. These findings underline our observation that oxygen admixture leads to less morphological alteration of the enamel.…”

“…While most plasma devices in preclinical and clinical use utilize pure argon gas for CAP generation, current research shows that the characteristics of the plasma effluent can be modified by admixing oxygen to the feed gas [2,3]. Regarding orthodontics, this raises the question which CAP composition is most suitable for bracket bonding.…”

Non-Thermal Plasma Treatment Coupled with a Photocatalyst for Antimicrobial Performance of Ihram Cotton Fabric

“…In our previous works [ 21 , 22 ], a plasma generated by an atmospheric pressure plasma jet (APPJ) was investigated in terms of its non-thermal, electrical, photographical, and spectroscopic characteristics, in the context of its antibacterial effects when coupled with a photocatalytic in culture media in the laminar flow mode.…”