Tailoring electrochromic properties using poly(N-vinylcarbazole) and poly(N-phenyl-2-(2′-thienyl)-5-(5"-vinyl-2"-thienyl)pyrrole) blends

Blends of poly(N-phenyl-2-(2'-thienyl)-5-(5"-vinyl-2"-thienyl)pyrrole) (PSNPhS) and poly(N-vinylcarbazole) (PVK) were prepared in mass ratios of 1:4, 3:2, and 4:1. Their electrochromic properties were characterized using cyclic voltammetry, in situ spectroelectrochemistry, and spectrocolorimetry. Solid-state electrochromic devices were prepared using ITO/Mylar substrates and a solid polymer electrolyte, with cast films of the polymer blends deposited on the working electrode. The color contrasts of these devices were measured by spectrocolorimetry conforming to the Commission International de l'Eclairage (CIE) methods. The observed color changes in the p-doped state of the devices were compared using the CIE color coordinate values and correlate (R-2 = 0.97) With the quantity of PSNPhS present in the blend, These combinations of PSNPhS and PVK yielded colors similar to those of natural vegetation and soils, as desired.