Modification of PET surface by nitrogen plasma treatment

A study on nitrogen plasma functionalization of polyethyleneterephthalate (PET) is presented. The samples of PET foils were exposed to a weakly ionized, highly dissociated RF nitrogen plasma with an electron temperature of 5 eV, a density of positive ions of the order of 10¹⁵ m^-3 and a density of neutral nitrogen atoms of the order of 10²¹ m^-3. The pressure was 75 Pa and a discharge power was 200 W. The PET-samples were exposed to plasma and its afterglow from 3 s to 10 s. After the treatment the surface was analysed by XPS (X-ray photoelectron spectroscopy). XPS results showed appearance of new functional groups like amine and amide.