PET surface modifications by treatment with monochromatic excimer UV lamps

Physical and chemical surface modifications of polyethyleneterephthalate (PET) films due to treatment with excimer UV lamps (222 nm) have been studied. Interpretations of the reactions and products were made in comparison to known PET irradiations with excimer UV lasers and broad-band UV sources. In this context the advantages of the excimer UV lamps as a light source, i.e., a quasi monochromatic radiation source with a power density which is sufficient for initiating surface reactions without changing the topography of the substrate, have been shown. Analytical data on treated PET to characterize the surface modifications were obtained by contact-angle measurements, dyeing with cationic dyestuff, scanning electron microscopy (SEM), photoacoustic Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) studies. With regard to possible industrial applications, the relevance for textile finishing and some perspectives for future developments are pointed out.