Contact angle determination on plasma-treated poly(ethylene terephthalate) fabrics and foils

The surfaces of polyester (PET) fabrics and foils were modified by low-pressure RE plasmas with air, CO2, water vapor as well as Ar/O-2 and He/O-2 mixtures. To increase the wettability of the fabrics, the plasma processing parameters were optimized by means of a suction test with water. It was found that low pressure (10-16 Pa) and medium power (10-16 W) yielded a good penetration of plasma species in the textile structure for all oxygen-containing gases and gaseous mixtures used. While the wettability of the PET fabric was increased in all cases, the Ar/O-2 plasma revealed the best hydrophilization effect with respect to water suction and aging. The hydrophilization of PET fabrics was closely related to the surface oxidation and was characterized by XPS analysis. Static and advancing contact angles were determined from the capillary rise with water. Both wetting and aging demonstrated a good comparability between plasma-treated PET fabrics and foils, thus indicating a uniform treatment. (c) 2006 Wiley Periodicals, Inc.