Anodic shrinking and compaction of polypyrrole blend: electrochemical reduction under conformational relaxation kinetic control

We describe, for the first time, the anodic compaction of the polypyrrole/p-toluenesulfonate blend. The subsequent electrochemical reduction until increasing negative potentials give chronoamperograms showing a shoulder at decreasing times for increasing potentials. In the context of the electrochemically stimulated conformational relaxation (ESCR) model, developed for cathodic compaction of basic polymers like polypyrrole, polyaniline or polythiophene, those shoulders can be attributed to a structural swelling with penetration of cations from the solution, occurring under conformational relaxation-nucleation kinetic control of the compacted polymeric chains. We checked the application of the ESCR model obtaining the charge consumed to relax one mol of polymeric segments from experiments performed by anodic compaction followed by a cathodic polarization. (C) 2003 Elsevier B.V. All rights reserved.