Solid Thermoplastic Laminable Electrochromic Film

A new kind of solid plastic electrochromic (EC) film, prepared by introducing EC molecules, belongingto a class of bipyridinium salts (viologens), and plasticizers into preformed solid thermoplastic polymers,is presented. The particularly easy preparation of this EC device makes it suitable for large-scaleapplications, by simple lamination of the film between conductive glasses. In this way it is possible toeliminate the disadvantages of fast EC films, due to the variation of the solvent organization around theEC molecules and to the onset of the hydrostatic pressure of the fluid layer which can break or separatefrom the glass supports. The electrochromic cells based on our solid films have undergone up to 105operational cycles in which coloring, bleaching processes, and stationary state conditions have been adjustedby applying suitable electric pulse sequences.