STUDIES ON STOICHIOMETRY OF ELECTROCHEMICAL POLYMERIZATION OF CONDUCTING POLYMERS

Counterions can be incorporated in a certain proportion as a part of conducting polymers on an electrode during electrochemical polymerization. The stoichiometric relationship between the resultant polymer weight (W), and the consumed charge (Q) and the ratio of counterion to monomer unit (x) was derived using polypyrrole as an example in this paper. The relationship was proven using electrochemical polymerization of polypyrrole with dodecyl sulfate, mandelate, perchlorate and chloride as counterions. It also indicated that W was nearly independent on x when the counterion molecular weight was close to 1/2 of monomer molecular weight. This was supported by the experiment using chloride as a counterion in polypyrrole.