Dielectric barrier discharge technique in improving the wettability and adhesion properties of polymer surfaces

A dielectric barrier discharge (DBD) in helium at atmospheric pressure was used to improve the polymer surface wettability as a first condition for ensuring a good adhesivity in particular for a subsequent immobilization of selected biological macromolecules (heparin, drugs, enzymes, etc.) on these surfaces. The DBD was analyzed by electrical measurements and optical emission spectroscopy. The polymer surface was characterized by thermodynamic parameters which may predict the adhesion properties, the adhesion work and the surface polarity, and also by its morphology. The results show that the DBD treatments improve the wettability and thus the adhesive properties due to the creation of functional groups and less due to a physical adsorption induced by an expected larger area of the treated surfaces. Dimensions of grains/crystallites are decreased on the treated surface, but a significant and systematic modification of the surface roughness was not observed.