Efficiency of electropolymerization of pyrrole onto carbon fibers

The efficiency of the electropolymerization of pyrrole onto carbon fibers has been studied. The dependence of the amount of polypyrrole coatings formed on the pH of the cell solution, the charge passed during electropolymerization and the reaction time has been determined. The amount of polypyrrole coatings formed increased with decreased pH of the cell solution and attained a maximum value at a pH < 3. The amount of coatings formed increased with increased total charge passed during electropolymerization. The weight of polypyrrole coatings formed per coulomb of charge passed rose to its highest value at short polymerization times, t < 300 s. It rapidly declined and then a leveled off at longer times, t > 300 s. The efficiency of electropolymerization was determined from the ratio of the experimental and theoretical hydrogen ion concentration. The efficiency of aqueous electropolymerization of pyrrole onto carbon fibers was determined to vary between 37 and 43%.