Electrochromism Subject

The reader may be aware that the terms electrochromism and electrochromic are also used in a large segment of literature to mean dyes whose absorption spectra are changed through redox reactions induced by electrochemical means. This subject is not included in this chapter. 

Electrochromic materials, which change color when subjected to an electric field, are widely explored for application as smart windows that control the amount of light reflected or transmitted. Color production is linked to defect formation in an otherwise colorless matrix. 

QDO, PDO, and related compounds are the subject of a great number of invention patents, particularly for its uses in material sciences. For example, QDOs were included in the formulation of modified unsaturated polymers and rubbers [174,175]. Polymers with a QDO substructure as monomeric unit were used to produce fibers, films, electrochromic elements, electrodes, semiconductors, and electrolyte solutions for secondary batteries [176-179]. 

An electrochromic display (BCD) is a thin solid state device that changes color reversibly when subjected to a small electrical potential. Since the doping processes of certain conducting polymers are accompanied by changes in the color, this effect has been conveniently exploited in the realization of BCD devices. Thin films of a conducting polymer polythiophene, for example, are red in the doped state and deep blue in the undoped state. 

Proton conducting perovskite oxides are the subject of numerous current studies, as these materials have a potential use in a number of electrochemical applications, including fuel cells, electrochromic displays and hydrogen sensors. Perovskite... 

The property of polythiophenes to change color upon the reversible oxidation/reduction process and the resulting electrochromic applications (e.g. smart windows) are the subject of the review Chapter 20 by Greg Sotzing and co-workers. 

An electrically controlled flexible colour-changing device can be obtained when an electrochromic material is apphed to textile. The first patent for such a structure was published in 1976 [70]. Since then, more than 30 patents have been pubhshed, with a notable increase since 2010, showing the considerable gain of interest in this subject. Over the same time, the role played by the textile material in these structures has increased. The 1976 patent describes a structure composed of two glass or plastic electrodes, coated with tin dioxide (as the electrode) and tungsten trioxide (as the... 

Soluble 3.4-disubstituted polythiophenes have found application as antistaticcomponents for film materials and are on the market electrochromic and electroluminescent devices are subject to intensive research and surely will be effective in the near future. Biosensor devices with functionalized polythiophene carrier systems for immobilizing enzymes are also applicable for the electro-analytical determination of analytes in micromolar concentrations. 

As it turns out, similar EC behavior has been observed in oligomeric polyaniline, and thus some effort has been directed toward preparing such systems as both model compounds to enhance the understanding of the behavior of PANI and as EC materials (23,30-33). Although these oligomers do not produce stable films and are subject to similar poor solubility, such structures hold promise since they can be incorporated into a well behaved polymer system In this way, it may be possible to construct uniform, electrochemically stable, and behaviorally predictable films containing this electrochromic fi agment. 

Electrochromic devices, where a transparent window can be turned opaque at selected regions of the electromagnetic spectrum under a potential, are another area in which PA copolymers and substituted PAs may have potential applications. Promising research opportunities also exist in the fabrication of PA-based controlled-release devices, non-linear optical devices, light-emitting diodes, and radar shielding. The readers are encouraged to consult some older [191-196] and more recent [197-199] review articles on these subjects. 

Indeed, the titles and subjects in the PART II APPLICATIONS section of this book -Batteries, Light Emitting Diodes, Sensors, E/0 Dences, Microwave Attenuation, Electrochromics, Anti-Corrosion, Electromechanical Actuators, lithography. Catalysis, Drug Delivery, Membranes- speak for themselves in this respect. They show the astoundingly wide applications of these unique polymers. 

As one of the prototypical CPs, the color changes associated with the Visible-region electrochromism of P(Py), subject to p-type (oxidative) doping, may be cited. For most conventional dopants, such as perchlorate, these are ... 

Electrically conducting polymers have been a subject of extensive studies in view of both academic interest and potential technological applications. This chapter describes the synthesis and properties of electrically conducting polymers and their applications as functional materials, such as electrode materials for secondary batteries, photoactive materials for photovoltaic devices, electrochromic materials, and materials for use in organic electroluminescent devices. 

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