Cleaning of glass surfaces using diffuse coplanar surface barrier discharge in ambient air
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| Year of publication | 2013 |
| Type | Conference abstract |
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| Description | We report a study on treatment of flat glass surfaces by ambient air atmospheric pressure plasma generated by a dielectric barrier discharge (DBD) with coplanar arrangement of electrode system – the so called Diffuse Coplanar Surface Barrier Discharge (DCSBD) [1]. The DCSBD atmospheric plasma system (Roplass, Czech Rep.) is made from multiple parallel stripline molybdenum electrodes embedded in 96% alumina. Dimensions of the alumina ceramic of DCSBD system are a = 93 mm in width and b = 230 mm in height and the total plasma area is about 80 mm x 200 mm. The 16 pairs of molybdenum comb-shape electrodes of width and inter-electrode distance c = 1.5 mm and d = 1 mm, respectively, were printed by green-tape technique on a 0.5 mm thick flat ceramic plate. The plasma is generated on the ceramic surface in thin 0.3 mm layer. We observed an influence of a glass on DCSBD plasma in respect to glass-ceramic distance z. The DCSBD plasma consists of two optically different segments: the diffuse plasma and the streamer plasma. We found that the introduction of a glass into DCSBD plasma led to increase of the diffuse plasma width w. This was explained mainly as a consequence of Meek’s breakdown criterion [2]. The study of a water contact angle with respect to glass-ceramic distance z showed that water contact angle depends strictly on z in small interval between 0.1 mm < z < 0.6 mm where the most effective treatment occurred. The X-ray Photoelectron Spectroscopy (XPS) technique was used to investigate the changes in surface chemistry before and after the plasma treatment of a glass. The results are summarized in Table 1. We found that the DCSBD plasma treatment for 3 s led to decrease of carbon concentration and C/Si ratio from 15 at.% to 4 at.% and from 0.69 to 0.15, respectively. The detailed study on high-resolution C1s peak shown that the plasma treatment for 3 s decreased C–C or C–H bonds concentrations while the concentrations of C–O and O–C=O bonds increased. Since the C–C and C–H bonds are related with the initial surface hydrocarbon contaminants this shows that the plasma treatment exhibits the cleaning effect of glass surface. Saturation on total amount of carbon reached after 3 s can be explained by fast accumulation of the carbon contaminants from ambient air during transportation of samples [3]. Acknowledgments The presented work has been supported by the project R&D center for low-cost plasma and nanotechnology surface modifications CZ.1.05/2.1.00/03.0086 funding by European Development Fund. |
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