Black and purple metal-like lustrous films from anion-doped poly(3-alkoxyselenophene) dyes†‡

Materials that exhibit metallic luster without containing metals are promising alternatives to existing metallic paints and coatings. In this study, we successfully synthesized four types of anion-doped poly(3-alkoxyselenophene) and used them to develop metal-free metal-like lustrous films. By employing polyselenophene, we achieved the expression of luxurious glossy colors such as black and purple, which were difficult to obtain with previously reported polythiophene-based materials. The developed films were thoroughly investigated through reflectance spectroscopy, colorimetry, gloss measurements, and XRD analysis. The glossy colors exhibited by the polyselenophene films are suggested to arise from a well-balanced presence of face-on and edge-on lamellar crystals within the coated films, in addition to the optical properties of the polymer itself. The developed metal-like lustrous films do not contain any metals, being highly promising for applications in essential everyday items such as writing instruments, cosmetics, anti-counterfeiting inks, and automotive paints.