Biomimetic Structural Electrochemistry from Conducting Polymers: Processes, Charges, and Energies. Coulovoltammetric Results from Films on Metals Revisited

Oxidation/reduction reactions in films of conducting polymers exchanging anions and solvent during reactions are revisited here and explored by voltammetric and coulovoltammetric results using Pt electrodes coated with films of different polymers, in different solvents and salts. The reactions induce molecular (conformational) and macroscopic (relaxation, swelling, shrinking, and compaction) structural changes. Coulovoltammetric loops constitute a direct graphical tool to identify, separate, and quantify the structural components of the reversible film reactions together the potential domains and the charges involved in irreversible reactions. Any abrupt slope variation is related to abrupt changes of the reaction rate associated with each of the structural induced processes. Charges, energies, and characteristic potentials for any of the structural or irreversible process are obtained. Reversible film reactions are present from -1.5 to 0.35 V versus Ag/AgCl, overlapping the irreversible hydrogen evolution at the metal/polymer interface below -1.1 V. Structural reduction energies are higher than structural oxidation energies and structural changes are energetically asymmetric. 3D reactive structural memories are envisaged stepping up storage density by orders of magnitude. Conducting polymers are 3D structural gel reactors at the polymer chain level: large anions in solution cannot penetrate inside the film. Composition changes and structural processes mimic intracellular matrix (ICM) biological reactions.