Preparation of Photostable Chlorophyll/PVA Film

Based on the principle that chlorophyll's photodegradation occurs in the presence of oxygen, high-oxygen-barrier polyvinyl alcohol (PVA) films comprising chlorophyll are prepared without photodegradation of chlorophyll by a facile procedure. The photostability of the films are characterized by the absorption spectra. The result shows that the chlorophyll in the films can keep photostable at least for six months whereas the photostability of chlorophyll in ethanol is less than one day. The absorption maxima of chlorophyll/PVA films at red band, which are at 668nm due to the chlorophyll and consist with that of chlorophyll in ethanol (666 nm), shift blue after the sunlight treatment. The shift extent increases with the time of sunlight treatment and decreases with the content of chlorophyll in samples. The method proposed in the study could greatly improve the photostability of chlorophyll and can be used in the field of photocatalysis.