Characterization of a Cold Atmospheric Pressure Plasma Jet Device Driven by Nanosecond Voltage Pulses

Abstract

The structure, fluid-dynamic behavior, temperature, and radiation emission of a cold atmospheric pressure plasma jet driven by high-voltage pulses with rise time and duration of a few nanoseconds have been investigated. Intensified charge-coupled device (iCCD) imaging revealed that the discharge starts when voltage values of 5-10 kV are reached on the rising front of the applied voltage pulse; the discharge then propagates downstream the source outlet with a velocity around 10 7 -10 8 cm/s. Light emission was observed to increase and decrease periodically and repetitively during discharge propagation. The structure of the plasma plume presents a single front or either several branched subfronts, depending on the operating conditions; merging results of investigations by means of Schlieren and iCCD imaging suggests that branching of the discharge front occurs in spatial regions where the flow is turbulent. By means of optical emission spectroscopy, discharge emission was observed in the ultraviolet-visible (UV-VIS) spectral range (N 2 , N + 2 , OH, and NO emission bands); total UV irradiance was lower than 1 µW/cm 2 even at short distances from the device outlet (<15 mm). Plasma plume temperature does not exceed 45 °C for all the tested operating conditions and values close to ambient temperature were measured around 10 mm downstream the source outlet.

Deposition of Plasma‐Polymerized Polyacrylic Acid Coatings by a Non‐Equilibrium Atmospheric Pressure Nanopulsed Plasma Jet

“…The plasma source adopted in this work is a single electrode plasma jet, suitable for the treatment of different substrates such as metals, polymers, glasses, and biological materials (Figure ), developed in our laboratory and previously reported in Refs …”

“…In the present work, results regarding the AA plasma polymerization process carried out on a polymeric substrate by using a non‐equilibrium atmospheric pressure nanopulsed plasma jet, are presented.…”

Studying the non-thermal plasma jet characteristics and application on bacterial decontamination

“…The lower mole fraction of air can lead to higher local electron concentration. This explains the higher emission intensity from excited species [28,29]. Some authors showed that the increase of gas flow rate is very significant to increase the amount of reactive oxygen and nitrogen species (RONS), which in turn contribute to cell death by damage of the DNA molecules [30].…”

Co‐Deposition of Plasma‐Polymerized Polyacrylic Acid and Silver Nanoparticles for the Production of Nanocomposite Coatings Using a Non‐Equilibrium Atmospheric Pressure Plasma Jet

“…The presence of nitrogen in the XPS survey spectrum can be probably appointed to the interaction of AA, or the products of its plasma-polymerization, with vibrationally excited N 2 molecules, resulting from the mixing of the plasma plume with the surrounding air, [43] as proposed by Bhatt et al [54] for the case of plasmapolymerization of diethylene glycol dimethyl ether; indeed, they observed by means of optical emission spectroscopy the formation of OH, CH, N 2 , and CN excited species when the monomer was introduced into the Ar plasma jet. The curve fitting of the high-resolution C 1s peak, shown in Figure 7, provides useful information on the retention of carboxyl groups in the chemical structure of the pPAA matrix of the nanocomposite coating.…”