Surface modification of PET film by plasma-based ion implantation

It has been reported that thin diamond like carbon (DLC) coating is very effective for enhancing the barrier characteristics of polyethylene terephthalate (PET) against CO2 and O-2 gases. However, coating technique has a problem of DLC-deposit peeling. In this research, we develop a new technique to change the PET surface into DLC by ion implantation instead of coating the surface with the DLC deposit. The surface of PET film is modified by plasma-based ion implantation using pulse voltages of 10 kV in height and 5 mus in width. Attenuated total reflection FT-IR spectroscopy shows that the specific absorption peaks for PET decrease with dose, that is, the molecules of ethylene terephthalate are destroyed by ion bombardment. Then, laser Raman spectroscopy shows that thin DLC layer is formed in the PET surface area. (C) 2003 Elsevier Science B.V. All rights reserved.