Conducting polymer-based controller

Conducting polymers have already been well documented in conjunction with the classical ionophore-based solvent polymeric ion-selective membrane as an ion-to-electron transducer. This approach has been applied to both macro- and microelectrodes. However, with careful control of the optimisation process (i.e. ionic/electronic transport properties of the polymer), the doping of the polymer matrix with anion-recognition sites will ultimately allow selective anion recognition and ion-to-electron transduction to occur within the same molecule. This is obviously ideal and would allow for the production of durable microsensors, as conducting polymer-based electrodes, and due to the nature of their manufacture these are suited to miniaturisation. There are various examples of anion-selective sensors formed using this technique reported in the literature, some of which are listed below. 

When control of structural parameters of the polymer is achieved, properties of the material will also depend on processing routes. Processing routes will have an inq)act on polymer chain conformation and then on localization of charge carriers. Polymers are mainly processed from solutions or from their molten state. We will show here the extreme importance of the conformation of polymers in solution when one is concerned with final electrical properties. The conformation of polymer in solution can be tailored by a careful choice of the solvent type, i.e. dielectric constant and solubility parameters or some added salts in the solution. Even in the case of extrusion, when the polymer is processed in the molten state, the prior conformation in solution plays an important role on the final properties of conductive polymer based blends. 

It was found that materials obtained through solution evaporation lead to a better reproducibility and high values of s while extruded materials could present wide diversion of resuhs. This point is essential for applications and ows that if conducting polymer based materials, with low content of conducting polymers (1-5 %w) permit to get suitable values for microwave applications, works remain to be done en values have to be severely controlled such as in the case of stealth applications (1). 

This reverse electrochemical control of the gel composition and volume is the basis for the singular electrochemical properties and the concomitant applications of conducting polymers. Reactions and properties based on polypyrrole films can be summarized as shown in Table 5 and below ... 

Given the actual scenario, one can state that the emerging field of nanotechnology represents new effort to exploit new materials as well as new technologies in the development of efficient and low-cost solar cells. In fact, the technological capabilities to manipulate matter under controlled conditions in order to assemble complex supramolecular structures within the range of 100 nm could lead to innovative devices (nano-devices) based on unconventional photovoltaic materials, namely, conducting polymers, fuUerenes, biopolymers (photosensitive proteins), and related composites. 

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