Corona discharge plasma

Birmingham J, Demirev P, EIo Y-P, Thomas J, Bryden W, Eenselau C. Corona plasma discharge for rapid analysis of microorganisms by mass spectrometry. Rapid Commun Mass Spectrom. 1999 13(7) 604-6. doi 10.1002/(SICI)1097-0231(19990415)13 7<604 AID-RCM529>3.0. 

Particularly in mass spectrometry, where discharges are used to enhance or produce ions from sample materials, mostly coronas, plasmas, and arcs are used. The gas pressure is normally atmospheric, and the electrodes are arranged to give nonuniform electric fields. Usually, coronas and plasmas are struck between electrodes that are not of similar shapes, complicating any description of the discharge because the resulting electric-field gradients are not uniform between the electrodes. 

The exact conditions of gas pressure, current flow, and applied voltage under which the discharge occurs determine if it is of the corona, plasma, or arc type. The color of the emitted light may also change, depending not only on the type of gas used but also on whether it is a corona, plasma, or arc discharge. 

Kirkpatrick, M.J., Finney, W.C. and Locke, B.R. (2003) Chlorinated organic compound removal by gas phase pulsed streamer corona electrical discharge with reticulated vitreous carbon electrodes, Plasmas and Polymers 8, 165-77. 

Figure 12-20. Point-to-plane plasma discharge system for pulsed corona discharge and spark in water.

Some plastics, notably polyolefins and acetals, are, however, highly resistant to bonding and need separate treatment to activate the surface. Commonly used treatment processes are flame treatment, electronic treatments such as corona discharge and plasma discharge, and chemical treatment. 

Biaxially oriented polypropylene [BOPP] surface modification by nitrogen atmospheric pressure glow discharge [APDD] and by air corona. Plasmas Polymers, Vol. 7, pp. 71-88, ISSN 1084-0184. 

Corona, dielectric barrier and plasma discharges, and, more recently, laser, y-ray and vacuum UV irradiations, have been used to modify the surface of cellulose fibres. This topic was recently reviewed [18] and here we will limit our coverage to the most significant results and to an update of recent contributions. 

Several fiber treatments are reported in literature [9], namely (a) physical treatments, such as solvent extraction (b) physico-chemical treatments, like the use of corona and plasma discharges or laser, y-ray and UV bombardment and (c) chemical modifications, both by the direct condensation of the coupling agents onto the cellulose surface and by various grafting strategies calling upon polycondensations and free-radical or ionic polymerizations. 

The various surfactants/treatments use include, but are not limited to, corona or plasma discharge, surface derivatization, graft copolymerization, acetylation. 

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