Nanostructuring of polymer surfaces by magnetron plasma treatment

Stochastic nanostructured polymer surfaces exhibit superior properties like enhanced antireflective behavior and soil- resistance as well as improved adhesion to adhesives and other coatings. This paper investigates the modification of surface chemistry and topography of different widely used polymers by means of a roll-to-roll reactive dual magnetron plasma etching process. The etching process induces formation of stochastic nanostructures on the surfaces. Structure shapes, texture and application relevant properties depend on the composition, morphology and crystallinity of the treated polymers. The impact on optical transmission and hydrophobic behavior of the surfaces are discussed. Nanostructured varnish coatings allow surface modification of inorganic surfaces that may not be etched directly in a plasma treatment. This paper therefore characterizes plasma etching of acrylic based varnish coatings on polymer webs. Structure formation is investigated in relation to surface active additive content in varnish material. Finally, the outdoor stability of a nanostructured ethylene tetrafluoroethylene (ETFE) surface is shown in a 24 month outdoor weathering test in central Europe.