Organic Electrode Reactions - Fundamentals and Applications of Organic Electrochemistry - page 175

monomer, which reduces the oxidation
potential of the monomer. This method is
therefore effective for polymerization of
aromatic monomers with relatively high
oxidation potentials. The reduction in
polymerization potential can avoid

overoxidation of product polymers.

5.8.4 Electrochemical Doping

If a polymer film on a working electrode is
obtained by electropolymerization, it should be
put into electrolytic solution without monomer
(monomer-free electrolyte) in order to study
the redox behaviour of the conducting polymer.
Typically a pair of broad redox responses is
observed in the voltammogram. The injection
or removal of electrons to or from conducting
polymers results in the formation of polarons
and bipolarons in the repeating structure
(commonly known as doping), producing
considerable variations in the physical
properties of the polymer itself and imparting
features such as drastic colour changes and
electrical conductivity [89]. The charges thus
generated along the polymer must be
compensated for by the addition of
neighbouring ions (or dopants) and the
insertion and release of such dopants may
induce volume changes in the conjugated
polymer. The doping ratio can be estimated
from the amount of charge generated in the
conducting polymers.