The wettability of polymer surfaces is an important consideration in some applications, for example where adhesion to the polymer surface is needed, such as when paint or functional coatings are applied to polymer substrates, or glue is used to stick a polymer substrate to something else. It may therefore be desirable to modify the polymer substrate surface.
Several methods for modification of polymer wettability have been reported. These include treatment with aggressive liquids, plasma and reactive gases. An already used method is treatment of polymer materials with gaseous plasma. A technological challenge, however, is formation of oxygen-rich functional groups on the surface of a fluorinated polymer. Currently used plasma treatment methods lead to etching rather than to functionalization of fluorine containing polymers with oxygen-rich functional groups.
A Slovenian research institute offers a novel method for modification of surface wettability of fluorine-containing polymers by a sequential two-step treatment.
The method is rapid and enables treatment of fluorine-containing polymers of almost any shape and size including ‘infinite’ materials such as foils. The wettability of objects made from, or containing, fluorine-containing polymers treated according to the methods of invention is close to the theoretical limit for smooth polymers – with this method a 20° water contact angle was achieved.
A surface finish with the novel method is stable and assures for long-lasting hydrophilicity of otherwise hydrophobic polymers. Unlike conventional treatment of fluorine-containing polymers with oxygen plasma, the novel method does not produce hazardous gases such as oxy- or peroxy-fluorinated carbon compounds.
The surface treatment method has been validated in the laboratory. Additionally, a device for surface treatment of fluorinated polymers in a batch or continuous mode has been developed.
The technology has been developed at the Slovenian research institute. The research group comprises experts in the field of surface treatment with emphasis on plasma technologies, thin films and vacuum science and have numerous experience in cooperation with industry.
The institute is looking for producers of PTFE products (cookware, plain bearings, gears, slide plates, seals, gaskets, bushings, wiring in aerospace and computer applications, etc.) and other fluoropolymeric products. The industrial partners are expected to enter license agreements with aim of implementation of the developed method in their production line.