Surface modification of polyethylene by medium pressure microplasma generator

Abstract

Polyethylene surface modification studies were performed in a new microplasma source using O₂ and N₂ gases. The degree of modification of polyethylene surface was qualitatively investigated through water contact angle measurements using distilled water. The influence of the plasma discharge parameters, such as gas nature, gas flow, power and exposure time, over the polyethylene contact angle was investigated. The obtained results indicate a decrease of the contact angle from 100° (for untreated sample) to 22·9°, when N₂ plasma was used for 40 s and discharge power >2 W. The surface morphology of the samples was examined by atomic force microscope and a smoothing effect after the plasma treatment was found. These results are very promising because of the experimental set‐up which requires medium vacuum, exhibit low process temperature (50–100°C) leaving the surface intact. Other advantages are the very short processing time (60 s) and applicability to large area substrates.