A New Plasma Electrolysis Technique in Archaeological Glass Cleaning

Archaeological glass pieces covered with soot, gypsum and black corrosion crust was cleaned for the first time by using novel plasma technique. Plasma electrolysis was done by gas discharging between a cathodic metallic pin and anodic water electrode. The glass pieces completely immersed inside the water and discharge take place over the surface of the water in open air. Different kinds of active species formed over and inside the water surface including OH, O, O3, atomic oxygen and hydrogen, H2, H2O2 and UV radiation. The cleaning mechanism will be discussed at discharge current 0.268 with exposure time range from 10: 15 min., applied at frequency (10 kHz) and sustaining voltage (500v). This current successfully removed 95.46% from soot and totally removed gypsum from the glass surfaces. Cleaning results for black corrosion were amazing. It could be concluded that, 0.268 A is considered the safest and successful current to be used in cleaning the archaeological glass samples despite the relatively long time of exposure to plasma. From the previous, it was clear that plasma electrolysis can be used successfully as a novel method in cleaning different types of small archaeological and historical glass. This method hasn’t been used yet with fragile, large-scale and outdoor archaeological and historical glass, so it needs future experimental work to be made.