High Rate Etching of Polymers by Means of an Atmospheric Pressure Plasma Jet

The impact of atmospheric pressure plasma on surfaces, in particular its potential application of modification and decontamination of different materials has been intensively investigated. In this study, the etching capability of an atmospheric pressure plasma jet is shown. A variety of polymers [e.g., polyethylene and poly (ether ether ketone)] was exposed to pure argon and argon/oxygen plasma. The influence of the oxygen admixture (up to 1%) and of the jet-nozzle to substrate distance on the etch rate of chemically different polymers was explored. Particular attention was applied on the feasible use of atmospheric pressure plasma on biofilm removal. For that reason a theory was postulated with each polymer representing a model compound of bacterial cells. The etch rates were obtained by determination of the mass loss and etch profiles after plasma exposure. The experiments showed that reactive oxygen species play an important role in the polymer removal which results in etch rates of 50 up to 300 nm . s(-1) depending on the polymeric material. These high etch rates imply that non-thermal atmospheric plasma jets could be used for removal of organic material including micro-organisms from surfaces.