Preparation of V2OX/Au-PPTA Flexible Composite Film and the Electrochromic Properties

Two kinds of flexible composite films, V2OX-PPTA and V2OX/Au-PPTA, were prepared by electrodeposition methods. The V2OX-PPTA film was obtained by electrooxidation of VOSO4 using the electrode with which poly (p-phenylene terephtal amide) (PPTA) film was covered as a matrix film. The V2OX/Au-PPTA film was obtained by over-electrodepositing gold on the V2OX-PPTA film. Both films exhibited bright electrochromism: from catholic to anodic polarization, dark green-green-yellow color change for the V2OX-PPTA film, and black green-dark green-red color change for the V2OX/Au-PPTA film. The electrochromic properties were examined using cyclic voltam-mograms, absorption spectra, XPS spectra, and so on; the red was estimated due to the lower valence vanadium. The film was self-supporting because the matrix film was mechanically strong and flexible.