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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:00 |
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Conference: Bucharest University Faculty of Physics 2015 Meeting
Section: Optics, Spectroscopy, Plasma and Lasers
Title:
Surface discharge plasma source for surface treatment
Authors:
Catalin PATRAS(1), Maximilian TEODORESCU(2), Maria-Daniela IONITA(2), Marian BAZAVAN(1), Gheorghe DINESCU(2)
Affiliation:
(1)Faculty of Physics, University of Bucharest, Magurele, 077125 Bucharest, Romania
(2)National Institute for Laser, Plasma and Radiation Physics, Magurele, PO Box Mg36, Bucharest, 077125, Romania
E-mail
maximilian.teodorescu@infim.ro
Keywords:
surface discharge, atmospheric pressure, radiofrequency, spectral study, wettability change.
Abstract:
The present-day plasma devices operating at atmospheric pressure used in industry are mostly based on two configurations: the DBE (Discharge with Bare Electrodes) and the DBD (Dielectric Barrier Discharge). The second is used mainly with one or two dielectric plates placed between the electrodes, confining thus the plasma generation.
In this paper we present a distinct type of device that uses the DBD configuration, but with a special geometry that makes use of a surface discharge on the inside of a glass tube. The tube has the annular power electrode placed on the inside in direct contact. The ground electrode is placed on the outside of the tube, also in direct contact with the glass tube, but shifted with a small distance compared to the power electrode position. The discharge is ignited using radiofrequency at 13.56MHz. Flowing Argon is used as the plasma gas. Due to the gas flow on the inside of the tube a surface discharge appears at the edge of the inner power electrode closer to the ground electrode position. This is a highly constricted discharge that has a dual behavior, in that at higher radiofrequency power values it develops into a multi-filamentary plasma coexisting with a weaker diffuse discharge. Using lower values for the applied power the discharge changes into a diffuse-only plasma. These aspects were investigated using digital photography.
The temperature of the discharge was measured using optical emission spectroscopy by fitting simulated spectra of the OH radical with the experimental data. The obtained values fall into the cold temperature domain, making this type of device suitable for surface treatment of different materials.
Silicon and Mylar samples were treated using the device, and wettability changes were measured using the contact angle method.
Acknowledgement:
This work was supported by a grant from the Romanian Ministry of National Education, CNCS-UEFISCDI, Project PN 09.39.01.03.
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