Polypyrrole electrochromic displays

Conducting polymers such as polyacetylene, polypyrrole, polyaniline, polythiophene, etc. have been actively studied for use in various fields due to their interesting properties batteries,46 electrochromic displays,47 materials for supercapacitors,48 corrosion protection,49 protecting layers for static electricity,50 materials for organic electroluminescence displays,51 sensing materials,52 etc. Polypyrrole is reported to be extremely rigid, with a semi-crystalline structure. 

A considerabel numbers of papers on fundamental studies of polymer-coated electrodes were published in various journals (e.g., Synth. Met., J. Chem. Soc., J. Electro-anal. Chem., Electrochim. Acta, Makromol. Chem., Macromol. Symp. 8 (1987)) in the year after this manuscript was completed. In several companies applied research works are on the way to realize application of these unconventional materials. Recently secondary batteries (polyaniline/Li, polypyrrole/Li) were commercialized. Developments for practical uses on electrochromic display and sensors are also underway. 

Optical quality thin films of metallic polymers are useful, therefore, as transparent electrodes [68]. For example, polyaniline [69], polypyrrole [70] and PEDOT [71] have been used as transparent hole-injecting electrodes in polymer LEDs (the initial demonstration of mechanically flexible polymer LEDs utilized PANl as the anode [69]). Transparent conducting films can be used for a variety of purposes for example, as antistatic coatings on CRT screens, as electrodes in liquid crystal display cells, or for fabricating electrochromic windows. 

Many electrochemically dopant-induced structure-property changes in conducting polymers have been described for use in, for example, electrochromic windows and displays, electrochemically controlled chemical separation and delivery systems, redox capacitors, electromechanical actuators, etc.,32. Some of these are apparently close to commercial application. Polypyrrole capacitors are already in conunercial production,27. 

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