STEADY-STATE VOLTAMMETRY OF SIMPLE AND POLYELECTROLYTE STRONG ACIDS WITH AND WITHOUT SUPPORTING ELECTROLYTE

Hydrogen ion is employed as the counterion to a polymer strong acid, p oly(styrenesulfonate), and to a monomer analog, p-toluenesulfonate. St eady-state currents for proton reduction at a microelectrode are used to characterize the dependence of diffusion, migration, and activity i n the presence of polyelectrolyte on concentration of supporting elect rolyte from zero to large excess. Use of microelectrodes makes the mea surements possible in the resistive dilute solutions. Measured diffusi on-migration currents for proton in p-toluenesulfonate solution agree well with those predicted. Similar predictions for poly(styrenesulfona te) based on a semiempirical model agree with experimental values to w ithin 2%. Steady-state voltammetry thus reflects accurately ionic tran sport in polyelectrolytic media and provides a simple, species-specifi c technique for investigating factors influencing transport in these s ystems.