Accurate in-situ gas temperature measurements in dielectric barrier discharges at atmospheric pressure

Wertheimer, M. R.; Ahlawat, Meenu; Saoudi, Bachir; Kashyap, Raman

doi:10.1063/1.4719208

Cited by 25 publications

(13 citation statements)

References 19 publications

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“…The gas temperature in the PJ was estimated using a Boltzmann plot analysis of rotational spectra corresponding to molecular nitrogen positive ion, using a method reliable for neon and helium DBD discharges. 78 The temperatures of $350 K were estimated for the external jet facing the tagret. Recent results have shown that exploitation of barrier discharge principles and the use of capillary dielectric tubes allowed the design and operation of a very low volume plasma source able to induce controllable effects on proteins and amino acids.…”

Section: He Plasma Jetmentioning

confidence: 99%

Effects of air transient spark discharge and helium plasma jet on water, bacteria, cells, and biomolecules

et al. 2015

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Atmospheric pressure DC-driven self-pulsing transient spark (TS) discharge operated in air and pulse-driven dielectric barrier discharge plasma jet (PJ) operated in helium in contact with water solutions were used for inducing chemical effects in water solutions, and the treatment of bacteria (Escherichia coli), mammalian cells (Vero line normal cells, HeLa line cancerous cells), deoxyribonucleic acid (dsDNA), and protein (bovine serum albumin). Two different methods of water solution supply were used in the TS: water electrode system and water spray system. The effects of both TS systems and the PJ were compared, as well as a direct exposure of the solution to the discharge with an indirect exposure to the discharge activated gas flow. The chemical analysis of water solutions was performed by using colorimetric methods of UV-VIS absorption spectrophotometry. The bactericidal effects of the discharges on bacteria were evaluated by standard microbiological plate count method. Viability, apoptosis and cell cycle were assessed in normal and cancerous cells. Viability of cells was evaluated by trypan blue exclusion test, apoptosis by Annexin V-FITC/propidium iodide assay, and cell cycle progression by propidium iodide/RNase test. The effect of the discharges on deoxyribonucleic acid and protein were evaluated by fluorescence and UV absorption spectroscopy. The results of bacterial and mammalian cell viability, apoptosis, and cell cycle clearly show that cold plasma can inactivate bacteria and selectively target cancerous cells, which is very important for possible future development of new plasma therapeutic strategies in biomedicine. The authors found that all investigated bio-effects were stronger with the air TS discharge than with the He PJ, even in indirect exposure.

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Section: He Plasma Jetmentioning

confidence: 99%

Effects of air transient spark discharge and helium plasma jet on water, bacteria, cells, and biomolecules

et al. 2015

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“…400 K, while the air plasma, generated by the PlasmaTreat system, saw these temperatures reach over 1900 K. The translational energy distribution of a gas is closely coupled to the population distribution among molecular nitrogen sublevels. It is therefore generally considered that the rotational temperature is similar to the kinetic gas temperature [31], this view however has recently been challenged by the use of fibre-optic based devices to obtain temperature measurement [32].…”

Section: Figure 4: Ftir Spectra Of the Aac Monomer (A) Plasmastream mentioning

confidence: 99%

Protein adhesion on water stable atmospheric plasma deposited acrylic acid coatings

Donegan

Dowling

2013

Surface and Coatings Technology

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There is considerable interest in the application of plasma polymerised acrylic acid (ppAAc) coatings due to their ability to enhance the adhesion of cells and proteins. An issue with this coating however it its stability in water and previous studies carried out using low pressure plasmas have demonstrated that high plasma powers are required to achieve water stable coatings. In this paper the use of both helium and air atmospheric plasmas are compared for the deposition of ppAAc coatings. The deposition studies were carried out on silicon wafer substrates using the PlasmaStream TM and PlasmaTreat TM plasma jet deposition systems respectively. The coatings were characterized using contact angle, FTIR, SEM, XPS, ellipsometry and optical profilometry. While both the helium and air plasmas were successful in the deposition of ppAAc coatings, the nm thick films deposited using the PlasmaTreat system exhibited significantly higher levels of water stability, probably due to a higher level of coating cross linking. Ellipsometry measurements demonstrated only a 0.2 nm reduction in the thickness of an 18 nm thick ppAAc coating, when immersed in an aqueous buffer solution for one hour. Protein attachment studies were carried out using a flow cell system, which was monitored using a spectroscopic ellipsometer. This study was carried out with Bovine Serum Albumin (BSA), Immunoglobulin G (IgG) and Fibrinogen (Fg) proteins. In all three cases increased levels of protein adhesion was observed for the ppAAc coating, compared to that obtained on the uncoated silicon wafer substrates.Keywords: Atmospheric Plasma, Thin Film, Nano-coatings, Surface Engineering, Protein Adhesion IntroductionControlling protein adhesion is an important issue affecting many different fields including bio-processing, medical device implants, biosensors, and drug delivery devices [1,2]. When the surface of a material interacts with a biological environment one of the initial interactions is through protein adhesion [3]. Amongst the factors influencing protein adsorption, are surface chemical functionality and morphology [4]. Amongst the techniques that have been investigated to modify the surfaces of polymers prior to protein adhesion studies have been micro patterning and monomer polymerisation by free radical solution, emulsion, grafting as well as plasma processes [5][6][7][8][9]. It has been demonstrated by a number of authors that plasma techniques enable both the surface functionality and morphology to be tailored [10,11]. This makes it possible to create a surface which will inhibit or enhance the rate of protein adhesion onto a biomaterial surface, without changing the properties of the bulk material [12].One surface chemistry that has received considerable attention for cell and protein adhesion has been acrylic acid. Surfaces containing this coating have been reported in applications ranging from platelet adhesion promotion [13], RGD peptide immobilisation [14], attachment of osteoblast-like [15], fibroblast [16] and keratinocyte [17]...

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“…This methods overestimates the gas actual temperature values, as obtained using others physical principles to return the gas temperature value. For example using alternative methods based on fiber optic temperature sensors, immune to electromagnetic interferences, returns an gas temperature increase of only few tens of degrees Celsius for helium dielectric barrier discharges [16,17]. During the last years, mass spectrometry studies of atmospheric pressure plasma jets became an appropriate technique to identify atomic and molecular species present in the plasma volume, either neutral or charged states.…”

Section: Introductionmentioning

confidence: 99%

Time Behaviour of Helium Atmospheric Pressure Plasma Jet Electrical and Optical Parameters

et al. 2017

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Low temperature plasma jets gained increased interest in the last years as a potential device in many life science applications, including here human or veterinary medicine. Standardisation of plasma sources and biological protocols are necessary for quality assurance reasons, due to the fact that this type of atmospheric pressure plasma source is available in multiple configurations and their operational parameters span also on a broad range of items, such as all characteristics of high voltage pulses used for gas breakdown, geometrical characteristics, gas feed composition and conductive or biological target characteristics. In this paper we present results related to electrical, optical and molecular beam mass spectrometry diagnosis of a helium plasma jet, emphasising the influence of various operational parameters of the high voltage pulses on plasma jet properties. Discussion on physical parameters that influence the biological response is included, together with important results on plasma sources statistical behaviour until reaching a quasi-stationary working regime. The warm-up period of the plasma jet, specific to many other plasma sources, must be precisely known and specified whenever the plasma jets are used as a tool for life science applications.

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Accurate in-situ gas temperature measurements in dielectric barrier discharges at atmospheric pressure

Cited by 25 publications

References 19 publications

Effects of air transient spark discharge and helium plasma jet on water, bacteria, cells, and biomolecules

Effects of air transient spark discharge and helium plasma jet on water, bacteria, cells, and biomolecules

Protein adhesion on water stable atmospheric plasma deposited acrylic acid coatings

Time Behaviour of Helium Atmospheric Pressure Plasma Jet Electrical and Optical Parameters

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