Surface modification of cyclic olefin copolymer substrate by oxygen plasma treatment

Cyclic olefin copolymer (COC) substrate surface was modified by plasma treatment under oxygen atmosphere. The surface properties were evaluated by contact angle measurement, atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS). It was found that the surface acquired oxygen containing polar functional groups such as C–O, C = O, which increased in number as the plasma treatment time increased. As revealed by AFM profile, these changes were accompanied by a slightly increase in roughness. The adhesive ability between the coating layer (ITO) and the COC surface can be improved after optimum plasma treating procedure, which can be proofed by the optical microscope observation after boiling test.