Polymer reversible doping

Conductivities of polymers of technological interest such as polypyrrole and polythiophene are typically 1000 cm in the doped state, and the conductivity can be tuned by reversibly doping and undoping the polymer. Derivatives of these and other polymers have achieved even higher conductivities. 

Polyacetylene in the doped state is sensitive to air and moisture. Other polymers (e.g., those of pyrrole, thiophene, and benzene) are stable in air and/or toward humidity in their doped and undoped states. Generally, when stored in the doped state, the polymers lose doping level by mechanisms not fully understood in most cases the loss is reversible. 

In the present paper we review some of our findings on the reversible photo-induced wettability changes of polymer surfaces doped with photochromic spiropyran molecules. We illustrate how the hydrophilicity of the surfaces is enhanced upon UV laser irradiation when the embedded non-polar spiropyran molecules convert to their polar merocyanine isomers and how this process is reversed upon irradiation with green laser pulses. Moreover, we show that, when the doped polymer surfaces are micropattemed by soft molding lithography or by interferometric... 

The conductivity of ICPs can be tuned in several ways, including modification of the polymer chain, variation of the type of dopants, the level of doping, and blending with other polymers. Usually, anions are incorporated during the synthesis of ICPs that neutralize the charge of the polymer. Unlike the inorganic semi-conductors, ICPs can be reversibly doped [Eq. (1)]. 

The capability of polypyrrole to be reversibly doped and dedoped by electrochemical methods makes this electroactive material adequate for the construction of rechargeable batteries [181-185]. The electroactive polymer can be either the anode or the cathode of the cell, although construction of anodes is most common, due to difficulties in inserting negative charges into polyheterocycles. Technical factors such as cyclability, energy density, and stability have to be optimized in the future, before commercial application of polypyrrole-based batteries. 

The capability of polypyrrole to be reversibly doped and dedoped by electrochemical methods makes this electroactive material a candidate for the construction of rechargeable batteries. A number of battery designs using conducting polymers have been described... 

One of the important applications of conducting polymers is their use as an electrode material for rechargeable batteries because of reversible doping. Thus n-doping is... 

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