Chemical reaction pathways at the plasma-polymer interface

The interaction of N-2 and O-2 glow discharges with polyethylene surfaces has been studied using mass spectrometry to characterize species permeating through toward the reverse side of the polymer substrate. Compared to previously reported diagnostic approaches, this method is capable of sampling reaction products within much closer proximity of the plasma-polymer interface, thereby circumventing the complication of primary product species undergoing secondary processes within the bulk of the electrical discharge prior to detection. The nature of the feed gas is found to strongly influence the chemical reaction pathways occurring at the plasma-polymer interface. Furthermore this approach opens up scope for isotopic studies.