Characterization and electrochromic properties of ultrathin films self-assembled from poly(diallyldimethylammonium) chloride and sodium decatungstate

Poly(diallyldimethylammonium) chloride (P) and sodium decatungstate (W) were layer-by-layer self-assembled onto quartz, mica, and ITO-electrode substrates (S). The self-assembled films, S-(P/W)(n), were characterized by absorption spectrophotometry, reflectivity, cyclic voltammetry and scanning force microscopy(AFM). The electrochemical properties of the S-(P/W)(n) films were found to differ from those in which the polyelectrolyte remained at the outermost layer, i.e., S-(P/W)(n)/P. Photoelectrochemical measurements provided evidence for the electrochromic and photoelectrochromic behavior of these films.