ABSTRACT
The decay of hydrophobicity manifested by the sessile droplet contact angles of water as well as of XPS F 1s peak intensity is observed in nylon 6 and PET films treated similarly. There is a direct linear correlation between the contact angles of water and the intensity of XPS F 1s peaks for each substrate polymer as shown in Figure 25.4. This correlation confirms that the increase and the decrease of the contact angle of water on the surface of plasma-treated films are due mainly to the change in the surface concentration of fluorine-containing moieties, which enable us to deal with the decay and the recovery phenomena by either measurement.
