Copolymerization and a self-assembly technique were used to build up a self-doped polyaniline (SPANI) ultrathin film on an indium tin oxide (ITO) substrate. The monomers used were aniline and its derivative OSAN (o-aminobenzenesulfonic acid). Successful OSAN-AN copolymerization and film formation were simultaneously performed in aqueous solution with the addition of oxidant (APS, ammonium persulfate). The film deposition rate of a high AN/OSAN ratio system is generally higher than that of a low AN/OSAN ratio system. Cyclic voltammetry, UV-vis spectroscopy, and film-thickness measurements indicate a systematic dependence of the film thickness of these ultrathin films on the assembly time and temperature. The Auger depth profile reveals the elemental distribution in these films, and exhibits different deposition rates between AN and OSAN. XPS N 1s spectra also show the variation of the degree of doping. This SPANI film can be used as an electrode in an electrochromic device. Waterborne polyurethane (WPU) blended with LiClO4 was used as a solid polymer electrolyte. A total solid electrochromic device was assembled as ITO/SPANI//LiClO4-WPU//PEDOT:PSS/ITO, where PEDOT:PSS is poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) as the counter electrode. The device was pale gray at -1.5 V and blue at +1.5 V.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films