Effect of polydopamine coating on improving photostability of poly(1,3,4-oxadiazole)s fiber

Effect of polydopamine coating on improving photostability of poly(1,3,4-oxadiazole)s (POD) fiber was studied in detail. Due to strong adhesion ability of polydopamine, the POD fiber could be coated easily by dopamine in Tris–HCl (pH = 8.5) solution at room temperature with exist of oxygen. The polydopamine coating was characterized by SEM, XPS and ATR-FTIR. It was proved by UV-spectra analysis that the polydopamine coating had a strong absorbance in ultraviolet wavelength and was very stable to ultraviolet. Additionally, it was found by pyrogallol autoxidation method that the polydopamine could efficiently capture superoxide anion radical, which was an important factor that resulted in photodegradation of POD fiber, due to its catechol structure. These two findings implied that polydopamine coating was a potential photoprotection agent. Finally, compared to POD fiber, the tensile test of POD fiber coated by polydopamine further proved that the polydopamine did improve the photostability of POD fiber. And the FTIR analysis of POD coated by polydopamine also confirmed that there was almost no macromolecular change after UV exposure.