Poly electrochromic behavior

Sonochemical methods have been used by the Cordoba de Torresi group to prepare Ni(OH)2, Co(OH)2 and mixed Ni/Co hydroxide NPs [33, 34]. For the sonochemical synthesis, the appropriate metal nitrate was mixed with ammonium hydroxide solutions and then sonochemically irradiated for various times. This produced about 5-nm diameter metal-hydroxide NPs that were then immobilized at ITO surfaces using a LbL approach with poly(allylamine) hydrochloride (PAH). In one study, the electrochromic behavior of the LbL deposits was compared with that of bulk deposits... 

Several such polymers have shown electrochromic behavior, among them poly(n-vinylcarbazole) [73] which switches from colorless in the neutral state to green in the doped state (Scheme 10) and poly(Ar-phenyl-2-(2 -thienyl)-5-(5"-vinyl-2"-thienyl)pyrrole) [74], which changes from yellow to reddish brown upon oxidation (Scheme 11). A study of the electrochromic properties of blends consist-... 

Huang, L.-M., T.-C. Wen, and A. Gopalan. 2002. In situ UV—visible spectroelectrochemical studies on electrochromic behavior of poly(2,5-dimethoxy aniUne). Synth Met 130 155—163. 

Reynolds et al. [279] reported electrochromic behavior of self-doped propanesulfonated poly(3,4-propylenedioxypyrrole). The polymer has not only shown interesting electrochromic properties in the visible, but, upon doping, also exhibits a very strong absorption in the near infrared with changes in transmittance up to 97 %, extending the use of the polymer as the active layer in a visible/near infrared switchable device. Viinikanoja etal. [280] reported the electrochromism and pH-induced halochromism of self-doped poly(3-(3 -thienyloxy)propanesulfonate) multilayers. 

Leclerc et al. [35] have compared POT and PMT with poly(2-ethylaniline) and poly(3-ethylaniline). Poly-(ethylanilines) show a similar electrochromic behavior to polytoluidines. They also exhibit similar optical properties as found for polytoluidines. Poly(ethylani-lines) exhibit multiple and reversible color changes (pale yellow-green-blue violet) depending on the oxidation state and the pH. Poly(2-ethyIaniline) shows a higher conductivity (1 S cm" ) compared to that of polytoluidines (0.3 Scm" ). Ryoo et al. [75] have compared the photoconductivity of POT with those of PANI, poly(o-ethylaniline) and poly(o-anisidine). The photoconductivity spectra of the polymers resemble their electronic absorption spectra. Therefore the band structures of POT and other PANI derivatives are similar to that of PANI. A major contribution to photoconductivity of these polymers comes from the n— n transition while the polaron—tt transition contributes to a lesser extent. Ryoo et al. [75] have proposed that photoexcitation leads to the oxidation of the polymer due to the removal of electrons. The bandgap energies of POT are the lowest (3.03 and 2.48 eV) while those of PANI are the highest (3.45 and 2.82 eV). 

Poly 5-(cyano-nonafluorobutylsulfonyl)cyclopenta[2,1 -b 3,4-b ]bithiophene has been prepared electrochemically forming a p- and -doping material for electrochromic devices. In a model device incorporated this polymer as both the anode and the cathode electrochromic behavior is demonstrated [190]. 

Pozo-Gonzalo, C., M. Salsamendi, J.A. Pomposo et al. 2008. Inflnence of the introduction of short aUtyl chains in poly(2-(2-thienyl)-lf/-pyrrole) on its electrochromic behavior. Macromolecules 41 (19) 6886-6894. 

The electrochemical behavior of poly(ferrocenylsilanes) has been studied at three levels—in solution by cyclic voltammetry, as films deposited on electrodes, and in the solid state via iodine doping. Solution cyclic voltammetric oxidation and reduction has shown that the polymer, where R/R is Me/Me, reversibly oxidizes in methylene chloride in two stages, apparently with the first oxidation being on alternating iron atoms along the chain.29 Films cast on electrodes behave in a similar way and also show an electrochromic response to oxidation and reduction.30... 

K-Conjugated polymers and oligomers are organic materials with many interesting and useful properties [1, 2], Examples of this class of materials include polyacetylene, polythiophene, polypyrrole, poly(phenylenevinylene) and their derivatives. Electronic conductivity, luminescence and nonlinear optical behavior are all observed in these materials and these properties have been exploited in applications such as electroluminescent devices (polymer light-emitting devices or PLEDs), electrostatic coatings, electrochromic windows, chemical sensors and memory devices [3-9]. 

HUANG, Y., CHEN, L., HO, K., Switching behavior of the Prussian blue-indium hexacyanoferrate electrochromic device using the K -doped poly-AMPS electrolyte, Solid State Ionics, 2003,165, 269-77. 

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