This paper reports the effects of long- distance and direct argon radio frequency (RF) plasma surface treatment on polyvinyl chloride (PVC) films in terms of changes in surface wettability and surface chemistry. The surface properties are char- acterized by the water contact angle measurement, X-ray photoelectron spectroscopy (XPS) and scan- ning electron microscopy (SEM). The mechanism is further analyzed and the role of all kinds of active species, e.g. electrons, ions and free radicals in- volved in plasma surface modification is further evaluated. Results show that the long-distance and direct RF plasma treatments modify the PVC surface in morphology and composition, and both modifica- tions cause surface oxidation of PVC films, in the forming of functional groups enhancing polymer wet- tability. The effect of the long-distance argon RF plasma is more notable. This suggests that long-distance argon RF plasma could restrain the ion and electron eroding effect and enhance free radical reaction.
