Electrochromic polymers characterization

This information can be obtained using various techniques. In situ UV-vis spectroscopy, electrochemistry and sur ce studies have been used to characterize electrochromic polymer films iq>on oxidation and reduction. We present here the investigation of BBB, BBL and PPTZPQ. 

S. P. Mishra, R. Sahoo, K. Krishnamoorthy, A.V. Ambade, A. Q. Contractor, and A. Kumar. 2004. Synthesis and characterization of electrochromic polymers based on 3,4-propylenedioxythiophenes. MACRO 2004, International Conference on Polymers for Advanced Technologies, Thiruvananthapuram, India, Dec. 15-17, (2004). Thiruvananthapuram Society for Polymer Science. 

A detailed investigation of PEDOT-S has been performed by Reynolds and coworkers. PEDOT-S— both chemically and electrochemically prepared— was characterized and studied regarding its electrochromic and its hole trans-portproperties. The electrochromic contrast was found tobelowerthaninmany other electrochromic polymers, but rapid switching could be performed. 

J. Xu, Y. Xian, R. Peng, Y. Xian, Q. Ran, and L. Jin. 2009. Ferrocene clicked poly(3,4-ethylenedioxythiophene) conducting polymer Characterization, electrochemical and electrochromic properties. Electrochem Cotntnun 11(10) 1972-1975. 

N. Leventis Y. C. Chung, Preparation And Characterization Of Tungsten Trioxide Dibenzyl Viologen Polymer Bilayer Electrochromic Films. J. Mater. Chem. 1993, 3, 833-839. 

The Dublin group has also reported a three-color electrochromic metallopoly mer 6 based on a ruthenium phenolate complex bound to poly(4-vinylpyridine). The reversible color changes (wine red to green) are associated with the Ru(II) oxidation, whereas the mixed redox state produces a red-orange. The charge transport parameters of the polymer were thoroughly characterized [27,28]. 

In spite of the fact that they do not lead to optical data, Raman, IR and FTIR [65] spectroscopies are choice methods to characterize the polymers and to study their chemical modifications. IR spectroscopy has the disadvantage of being used only with technical complexities in the presence of an electrolyte, while Raman spectroscopy proved from the pioneer papers published in 1987 [60,66] to be a very reliable technique for the study of PANI, and can be used very easily in situ. The spectral modifications associated with the percentage of doping [67], with pH [68], with the physico-chemical treatments of as-prepared PANI [36] or with the polymer degradation following the electrochromic cycles [69,70,71] have been studied by Raman spectroscopy. Finally, RS and Optical Spectroscopy were associated several times [40,71,72], by reason of their mutual contribution. 

Hsiao SH, Liou GS, Kung YC, Lee YJ. Synthesis and characterization of electrochromic poly(amide-imide)s based on the diimide-diacid from 4,4 -diamino-4"-methoxytriphen-ylamine and trimellitic anhydride. Eur Polym J2010 46(6) 1355-66. 

All conjugated polymers are potentially electrochromic with the intrinsic optical properties determined by the polymer s tt-tt transition, which is characterized by the polymer s bandgap and [5,16,17]. The value of the optical bandgap is determined by the onset of the tt-tt transition for the pol)mer in the undoped state. 

While an invaluable tool in producing conjugated polymers on conducting substrates, electropolymerization has limitations that include a lack of primary structure verification and characterization along with the inability to synthesize large quantities of processable polymer. To overcome the insolubility of PEDOT, a water-soluble polyelectrolyte, poly(styrenesulfonate) (PSS) was incorporated as the counterion in the doped PEDOT to yield the commercially available PEDOT/PSS (Baytron P) (39), which forms a dispersion in aqueous solutions [140]. While this polymer finds most of its application as a conductor for antistatic films, solid state capacitors, and organic electronic devices, its electrochromism is distinct and should not be ignored. 

Loveday, D.C., M. Hmyene, and J.P. Ferraris. 1997. Synthesis and characterization of p- and n-dopable polymers. Electrochromic properties of poly-3-(p-trimethylammoniumphenyl)bithio-phene. Synth Met 84 245. 

Impedance Spectroscopy. Impedance spectroscopy has been carried out on devices with WO3 as the cathodic electrochromic layer, counter electrodes of iridium oxide, polyaniline or Prussian blue, and polymers as electrolytes (Katsube et al [1986], Friestad et al [1997]). The equivalent circuit for a whole device becomes very complicated. In the works quoted above simplified, Randles-type circuits were used for the two electrochromic layers, while the ion conductor was modeled by a pure resistance, or neglected. Extraction of device parameters from the data fitting was reported. However, it is clear that in many cases it will be difficult to distinguish the contributions from the different layers in a device, in particular if the migration impedances, ion diffusion impedances, etc. are of the same order of magnitude. When it comes to characterizing electrochromic devices, impedance spectroscopy is a very time-consuming process, since a spectrum down to low frequencies should be taken at a number of equilibrium potentials. Thus we believe that transient current measurements in many cases offer a faster alternative that sometimes allows a simple determination of diffusion coefficients. 

We describe die moiphologicai, electrochemical, spectroelectrochemical characterization, and electrochromic device properties of several polymer films ladder poly(benzobisiniidazobenzophenandiroline) (BBL),... 

We report here morphological, electrochemical and spectroelectrochemical studies of semiladder poly(benzobisimidazobenzophenanthroline) (BBB), ladder poly(benzobisimidazobenzophenanthroline) (BBL) and poly(2,2 -[10-mediyl-3,7-phcnothiazylene]-6,6 -bis[4-phenylquinoline]) (PPTZPQ) e structures are shown in Figure 2. We also describe the construction and characterization of die electro-optical properties of all-polymer electrochromic devices using PPTZPQ as one electrode and BBL, BBB or V2O5 as die counter electrode. 

Subsequent to isolation of the polymer, the metallization could be conducted in a similar manner as that of the complexes reported elsewhere for DCH-Ru complexes (27-28). The ruthenium complex polymers, shown in Figure 2, thus made would be expected to exhibit similar electrochromic properties as the dinuclear ruthenium complexes while possessing the film forming characteristics of the parent polymer. We report herein the synthesis and characterization of these polymers. 

IR and visible light electrochromic characterization of Th-CNV-EDOT was performed by employing an experiment where the potential was stepped rapidly between the completely oxidized or neutral (labeled Red in the figure) states. The percent transmittance at the (610 nm), 1064 or 1550 nm was measured simultaneously. The switching results for 610 and 1064 nm are shown in Figure. 3. The relative position of the oxidized and neutral forms of the polymer are inverted in... 

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