The surface dynamic behaviors of PET modified by CF~4/CH~4 plasmas were investigated by static state, dynamic contact angle and X-ray photoelectron spectroscopy (XPS) techniques. It was found that the hydrophobic characteristics of the modified PET surface decreased through water immersion. Decay constant k of Surface Dynamics of the modified surface can be calculated using the measurement results of the contact angle and the angle-dependent XPS, being a probe, k values can be used to characterize the surface dynamic behavior of the modified PET. Experiments proved that the CF~4/CH~4 plasmas show stronger hydrophobic effect than that of pure CF~4 plasma alone.

Key words: CONTACT ANGLE, X-RAY PHOTOELECTRON SPECTROMETRY, CARBONTETRAFLUORIDE, METHANE, MIXTURE OF GASES, PLASMAS, ATTENUATION CONSTANT, POLYETHYLENE TEREPHTHALATE, SURFACE PROPERTY, HYDROPHOBILITY