The solid-phase photocatalytic degradation of polyvinyl chloride (PVC) film in air was investigated . The photodegradation of the PVC and PVC-TiO2 was compared with that of plasma-treated PVC and plasma-treated PVC-TiO2 in terms of weight loss and scanning electron microscopic (SEM) analysis. The results show that the weight loss of plasma-treated PVC film is only 1.536%, while the weight loss of PVC-TiO2 film treated by plasma amounts to 1.966% . The SEM of the PVC-TiO2 film treated by plasma shows that there is a lot of crack on the surface after photodegradation. Furthermore, the surface wettability and surface structure of PVC after nitrogen plasma treatment were characterized by using contact angle and surface tension detector, X-ray photoelectron spectroscopy (XPS), and electron spin resonance (ESR). The experiment indicates that the surface free energy and wettability of PVC treated by plasma increase greatly. XPS analysis of the plasma-treated PVC film shows that the surface concentration of oxygen increases while that of chlorine decreases after plasma treatment. ESR analysis reveals that the signal of radical on the surface of the plasma-treated PVC film is enhanced after treatment. The free radicals on the surface of plasma-treated PVC get the activating energy of photocatalytic degradation decreased because of higher chemical activity of the free radicals , which favors the photodegradation of plasma-treated PVC-TiO2.
DownLoad: