Wettability control of PET surface by plasma-induced polymer film deposition and plasma/UV oxidation in ambient air

Publication date: 5 November 2018Source: Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 556Author(s): Keiko Gotoh, Eriko Shohbuke, Yasuyuki Kobayashi, Hirohisa YamadaAbstractThe surface modification of poly (ethylene terephthalate) (PET) film was achieved by two sequential atmospheric pressure plasma jet (APPJ) treatments: plasma-induced polymer coating with hexamethyldisiloxane (HMDSO) and plasma oxidation with nitrogen gas. For comparison with APPJ-oxidation, oxidation by excimer ultra violet (UV) light irradiation was performed. The sessile drop and Wilhelmy contact angle measurements revealed that the PET film subjected to APPJ-coating showed superior water repellency and subsequent APPJ- or UV-oxidation made the PET film super-hydrophilic. UV-oxidation was also performed on the PET film treated by APPJ-coating, covered by a metal mesh. The difference in the contact angles between the surface areas covered with and without the metal strip mask was evident based on the Wilhelmy contact angle measurement. Both hydrophobic and hydrophilic surfaces did not exhibit contact angle hysteresis and had excellent stability of wettability. Furthermore, the hydrophilic surface treated only by APPJ- or UV-oxidation exhibited contact angle hysteresis and hydrophobic recovery with prolonged storage. Field emission scanning electron microscopy (FE-SEM) and SEM observation revealed that the morphology of the PET surface became granular after APPJ-coating. From the...

Source: Colloids and Surfaces A: Physicochemical and Engineering Aspects - August 14, 2018 Category: Chemistry Source Type: research