Electrochromic polymers poly

Sonmez, G., H. Meng, Q. Zhang, and F. Wudl. 2003. A highly stable, new electrochromic polymer Poly(l,4-bis(3, 4 -ethylenedioxy)thienyl)-2-methoxy-5,2"-ethylhexyloxybenzene. Adv Funct Mater 13 (9) 726. 

The other important electrochromic polymers are the polypyrroles and polythiophenes, obtained by polymerisation of the parent pyrrole and thiophene or, more importantly, their 3,4-substituted derivatives. The most widely studied of these two classes of polymers in electrochromic outlets are the poly thiophenes, which are readily synthesised by the reaction of the substituted monomer with FeClj in chloroform solution. The colour change properties of a variety of poly thiophenes in the presence of a counter-ion are shown in Table 1.14. ... 

In the most important series of polymers of this type, the metallotetraphenylporphyrins, a metalloporphyrin ring bears four substituted phenylene groups X, as is shown in 7.19. The metals M in the structure are typically iron, cobalt, or nickel cations, and the substituents on the phenylene groups include -NH2, -NR2, and -OH. These polymers are generally insoluble. Some have been prepared by electro-oxidative polymerizations in the form of electroactive films on electrode surfaces.79 The cobalt-metallated polymer is of particular interest since it is an electrocatalyst for the reduction of dioxygen. Films of poly(trisbipyridine)-metal complexes also have interesting electrochemical properties, in particular electrochromism and electrical conductivity.78 The closely related polymer, poly(2-vinylpyridine), also forms metal complexes, for example with copper(II) chloride.80... 

The carbazole polymer poly(iV-vinylcarbazole) functions as a positive electrode material for a secondary lithium battery <85CC553>, and as a memory photoreceptor <91M1 204-0l>. The related poly[3-(3-bromocarbazol-9-yl)propyl]methylsiloxane (18) forms novel electrochromic films <89CC196>. Carbazole anions have b n used to initiate the polymerization of acrylates and methacrylates <95CC275>. The novel polymeric pyrrolocarbazole (19) displays physical properties similar to those of polyanilines. 

S.-H. Cheng, S.-H. Hsiao, T.-H. Su, and G.-S. Liou. Novel electrochromic aromatic poly(amine-amide-imide)s with pendent triphenylamine structures. Polymer, 46(16) 5939-5948, July 2005. 

Karabay, B., Pekel, L.C., Cihaner, A., 2015. A pure blue to highly transmissive electrochromic polymer based on poly(3,4-propylenedioxyselenophene) with a high optical contrast ratio. Macromolecules 48, 1352-1357. 

Gaupp C. L., Welsh D. M., and Reynolds J. R, Poly[ProDOT-Et2] a high-contrast, high-coloration efficiency electrochromic polymer, Macromol. Rapid Commun., 2002,23,885-889. 

Cheng SH, Hsiao SH, Su TH, Lion GS. Novel electrochromic aromatic poly (amine-amide-imide)s with pendent triph-enylamine structures. Polymer 2005 46(16) 5939 8. 

Hsiao SH, Guo W, Kung YC, Lee YJ. Redox-active and electrochromic aromatic poly(amide-imide)s with 2,4-dimethoxyt-riphenylamine chromophores. J Polym Res 2011 18(6) 1353-64. 

Schottland, R, K. Zong, and C.L. Gaupp. 2000. Poly(3,4-alkylenedioxypyrrole)s Highly stable electronically conducting and electrochromic polymers. Macromolecules 33 7051-7061. 

Examples of electrochromic polymers bearing perfluoro chains (poly(54)) [147], dendrons (poly(170)), or viologen groups, e.g., (poly(171)) [150] have been reported. In this later case, introduction of a second electrochromic viologen pendant group increases the contrast between the oxidized and the neutral states. 

Sankaran, B., and J.R. Reynolds. 1997. High-contrast electrochromic polymers from alkyl-deriva-tized poly(3,4-ethylenedioxythiophenes). Macromolecules 30 2582-2588. 

Krishnamoorthy, K., A.V. Ambade, M. Kanungo, A.Q. Contractor, and A. Kumar. 2001. Rational design of an electrochromic polymer with high contrast in the visible region Dibenzyl substituted poly(3,4-propylenedioxythiophene). J Mater Chem 11 2909-2911. 

Reeves, B.D., B.C. Thompson, K.A. Abboud, B.E. Smart, and J.R. Reynolds. 2002. Dual cathodically and anodically coloring electrochromic polymer based on a spiro bipropylenedioxythiophene [poly(spiroBiProDOT)]. Adv Mater 14 717-719. 

Through the introduction of ester groups at the 3-position of the thiophene ring, electrochromic polymers were formed that were more hydrophilic than poly(3-alkylthiophene)s due to the polar ester group substitution. Two examples, poly(3-methyl-butyric acid 2-thiophen-3-yl-ethyl ester) (7a) [63]... 

Electrochromic polymer films have been made where the carbazole unit is not part of the main chain of the polymer, e.g., poly-iM-vinylcarbazole (29) [107—109]. When electrochemically polymerized, it has been shown that the cation radical of the carbazole unit easily dimerizes to form a 3,3 -bicarbazolyl that is more easily oxidized than the parent monomer. These films also show a colorless to green transition upon oxidation. Similarly, films of poly[3-(3-bromocarbazol-9-yl)propyl]methylsiloxane (30) have been prepared where the carbazole dimerizes creating a cross-linked film that switches between colorless and green as with the other polymers [110]. 

Films prepared in a similar manner with Hydrin C are those utilizing poly(N,N -dimethyl-2,2 -bipyrrole) [220], and polypyrrole [221]. Electrochromic films of Hydrin C and poly(o-methoxyaniline) have also been produced in which the aniline polymer is chemically polymerized in the presence of p-toluene sulfonic acid and blended with Hydrin C with the blend cast from solution [219]. Another example in which an electrochromic polymer was electrochemically polymerized in the presence of an insulating polymer is that of polypyrrole-polyjether urethane) or polypyrrole-poly(ethylene-co-vinyl alcohol) composite films [222]. Both films switched between a yellow reduced state to a bluish brown oxidized state, similar to polypyrrole. 

Gaupp, C.L., K. Zong, P. Schottland, B.C. Thompson, C.A. Thomas, and J.R. Reynolds. 2000. Poly(3,4-ethylenedioxypyrrole) Organic electrochemistry of a highly stable electrochromic polymer. Macromolecules 33 1132-1133. 

Welsh, D.M., A. Kumar, M.C. Morvant, and J.R. Reynolds. 1999. Fast electrochromic polymers based on new poly(3,4-alkylenedioxythiophene) derivatives. Synth Met 102 967-968. 

Sbnmez, G., I. Schwendeman, P. Schottland, K. Zong, and J.R. Reynolds. 2003. N-substituted poly(3,4-propylenedioxypyrrole)s High gap and low redox potential switching electroactive and electrochromic polymers. Macromolecules 36 639-647. 

Poly (thiophene)s are of particular interest as electfochromic materials owing to their chemical stability, ease of synthesis and processability. For the most part, current research has been focused on composites, blends and copolymer formations of several conjugated polyheterocyclics, polythiophene and its derivatives, especially PEIX)T. In one example, poly(3,4-ethylenedioxythiophene) (PEDOT)/poly(2-acrylamido-2-methyl-l-propanesulfonate) (PAMPS) composite films were prepared by Sonmez et al. for alternative electrochromic applications [50]. Thin composite films comprised of PEDOT/PAMPS were reported to switch rapidly between oxidized and neufial states, in less than 0.4 s, with an initial optical contrast of 76% at A.max. 615 nm. Nanostructured blends of electrochromic polymers such as polypyrrole and poly(3,4-ethylenedioxythiophene) were developed via self-assembly by Inganas etal. for application as an electrochromic window [26]. Uniir etal. developed a graft-type electrochromic copolymer of polythiophene and polytetrahydrofuran for use in elecfiochromic devices [51]. Two EDOT-based copolymers, poly[(3,4-ethylenedioxythiophene)-aZ/-(2,5-dioctyloxyphenylene)] and poly[(3,4-ethylenedioxythiophene)-aft-(9,9 -dioctylfluorene)] were developed by Aubert et al. as other candidates for electrochromic device development [52],... 

Polythiophenes with P-alkyl substituents including more than three carbon atoms are commonly soluble in organic solvents. Recently, electrochromic polymers such as poly(thiophene-3-acetic acid) and its copolymer with polythiophene were prepared. The electrochromic properties of these materials were studied by observing a color change from red to black during the potential sweep with a stability for 264 cycles, establishing a high electrochromic efficiency of up to 242 cm C at 750 nm [65],... 

---