Abstract: The surface of polyethylene terephthalate film was modified using radio frequency RF-Ar plasma under a working pressure of 20 Pa and a power of 60 W for different length of time. The changes of hydrophilicity and surface structure of the film before and after modification were analyzed with static contact angle measurement, Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy. It showed that the contact angles were gradually decreased with increasing treatment time within 0~120s, however, further treated for longer time caused no further changes and remained in the region between 22° and 23.5°. Polar groups such as C-N, N-C=O, C=O, C-O were formed on the treated film surface. Meanwhile, the surface roughness was increased and appeared conical or globular protuberances.

Key words: RF-Ar plasma, poly(ethylene therephthalate), hydrophilicity, surface structure, film