The Quest for Extra Functionality

It has proved possible to add a wide range of additional functionalities to the parent polypyrrole (PPy) structure, opening up an exciting array of potential applications for these materials. Two distinct approaches to achieving this additional functionality have been successfully employed, namely  

Covalent attachment of specific groups to the PPy backbone (either before or after polymerization) 

Incorporation of specific dopant anions (as discussed previously in this chapter) 

The attachment of simple substituents such as alkyl or methoxy groups to the backbone of PPy s is well known to markedly enhance their solubility in organic solvents and, consequently, their processability (see the preceding text). Covalent binding of more sophisticated substituents to PPy can provide a wide range of other attributes. A number of these are discussed in the following text, with particular emphasis on the synthesis of derivatized PPy s with sensing capabilities. 

An optically active PPy 17 has also been synthesized by the electropolymerization of pyrrole monomer bearing a homochiral sugar covalently attached to the pyrrole nitrogen.132 This chiral polymer discriminated between (+)- and (-)- cam-phorsulfonate ions as potential anionic dopants in cyclic voltammetry studies. 

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The counterion/cation effect choice of electrolyte The monomer Chemical polymerization The quest for extra functionality Molecular Structure and Microstructure of Polypyrrole Molecular Weight, Branching and Crosslinking Crystallinity and Molecular Order Surface Morphology and Film Density References... 

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