Conducting polymers history

One early program carried out at AUied-Signal, Inc. proposed the use of conductive polymers in remotely readable indicators (210). Conductivity changes induced in the conductive polymer could be read externally and the history of the sample known. Systems designed to detect time—temperature, temperature limit, radiation dosage, mechanical abuse, and chemical exposure were developed. 

Photovoltaic (PV) cells, 23 32-53. See also Photovoltaic materials commercial history of, 23 49—51 conducting polymer applications, 7 541 polymethine dyes in, 20 516—517 selenium, 22 100, 103 spectrum and band gap of, 23 37-39 structure of, 22 220-221 third generation, 23 44 workings of, 23 32-37 Photovoltaic detectors, 19 133, 138 Photovoltaic detectors/arrays/focal planes, 19 163-164... 

A very important electrochemical phenomenon, which is not well understood, is the so-called memory effect. This means that the charging/discharging response of a conducting polymer film depends on the history of previous electrochemical events. Thus, the first voltammetric cycle obtained after the electroactive film has been held in its neutral state differs markedly in shape and peak position from subsequent ones [126]. Obviously, the waiting time in the neutral state of the system is the main factor determining the extent of a relaxation process. During this waiting time, which extends over several decades of time (1-10 s), the polymer slowly relaxes into an equilibrium state. (Fig. 13) After relaxation, the first oxidation wave of the polymer appears at more... 

The first and most important event in the history of conducting polymers occurred in 1978 when it was announced that the electrical properties of polyacetylene could be dramatically changed by chemical treatment (Chiang et al, 1978). 

Armand (1994) has briefly summarised the history of polymer electrolytes. A more extensive account can be found in Gray (1991). Wakihara and Yamamoto (1998) describe the development of lithium ion batteries. Sahimi (1994) discusses applications of percolation theory. Early work on conductive composites has been covered by Norman (1970). Subsequent edited volumes by Sichel (1982) and Bhattacharya (1986) deal with carbon- and metal-filled materials respectively. Donnet et al. (1993) cover the science and technology of carbon blacks including their use in composites. GuF (1996) presents a detailed account of conductive polymer composites up to the mid-1990s. Borsenberger and Weiss (1998) discuss semiconductive polymers with non-conjugated backbones in the context of xerography. Bassler (1983) reviews transport in these materials. 

A concise report describing the history and scope of the studies in the area of conducting polymers can be found in Kanatzidis, M. G. Chem. Eng. News, 1990, 68, 49, 36. 

Why should conductive polymers in particular, which have not yet become really useful materials, behave in a fundamentally different way from metals or thermoplastic polymers, in which purity, degree of crystallisation, lattice structure and processing history have crucial influences of a quantitative and qualitative nature on electrical and mechanical properties In this respect 1 would mention a number of absolutely classic examples ... 

Polymers by D. Walton and P. Lorimer, Oxford Chemistry Primers, OUP, 2000. This book, as the series to which it belongs suggests, is largely devoted to the polymerisation and physical chemistry of polymers, but it also includes some history and a section on conducting polymers. 

A Brief Overview and History of the Development of Conductive Polymers... 

From the beginning of their history in the late 1970s, conductive polymers (organic metals) have been considered as intractable and insoluble. It was an important goal in basic research as in application-oriented materials science to develop techniques by which they could be processed. The use of solvents was one of the options. As early as 1983-84, after five years of research, we happened to create the first clear dispersions of polyacetylene, polypyrrole, and polyaniline [42], with and without the presence of conventional polymeric binders. This was the beginning of nanotechnology with organic metals. 

A review of the history of the development of silicon MEMS shows that production of single devices for mass markets has been the dominant pattern in commercialization. The first products were pressure sensors for the automobile mass market. Next came the accelerometers for the same market, and more recently optical switches and ink-jet printheads. Similar parallels can be seen in the development of conducting polymer devices. Of the wide variety of prototype sensors, actuators, and electrical components that have been demonstrated over the past 10-15 years, only polymer LEDs have been completely commercialized. Smart systems utilizing MEMS and conjugated polymers, which were anticipated to be the killer app, have yet to make their appearance. 

As in many other cases in the history of science, there were several precursors to this discovery, including theoretical predictions made by physicists and qnantum chemists, and different conducting polymers that had already been prepared. For instance, as early as 1862, Henry Letheby prepared polyarriline by the anodic oxidation of aniline, which was condnctive and showed electrochromic behavior [9],... 

We could compile the stories of polypyirole and other conducting polymers in a similar way, but the polyaniline saga alone provides an excellent illustration of the development of science. In fact, the discovery in the 1970s of polyacetylene— which had no practical importance but helped to arouse the interest of researchers and public alike— was another episode in the history of conducting polymers. Thus, these materials have a long history and— perhaps without any exaggeration—a bright future. 

As the brief history of conducting polymers tells, initially physicists played the dominant role in research of these materials. Naturally, they borrowed names for the species and phenomena from the nomenclature of their own field, as we have already seen in the case of doping. The terms polaron, bipolaron, and sometimes soliton are frequently seen in the literature on conducting polymers. These terms have been borrowed from solid-state physics. By polaron (Fig. 2a) in connection with CPs we mean radical ion introduced by oxidizing or reducing a conducting polymer molecule. The simple molecular orbital theory shows that the charge of a... 

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