Interfering Effect of Surfactants on Electrochemistry of Poly(pyrrole) Conducting Polymer Films

摘要

The effect of anionic,non-ionic and cationic surfactants in solution on electrochemical responses of poly(pyrrole) films were studies.It was found that surfactants present in solution in mmol/dm~3 concentrations practically do not affect voltammetric behavior of cation-exchanging poly(pyrrole) films doped with hexacyanoferrate ions.In contrary,for anion-exchanging poly(pyrrole) films doped with chlorides,PPyCl,charge transfer process observed under conditions of voltammetric experiment was significantly,irreversibly,inhibited by surfactants in solution in mumol/dm~3 concentration;regardless the charge of surfactant molecule.As shown by AC voltammetric experiments the choice of frequency (time) scale can be used to amplify or suppress the conducting polymer sensitivity of the current response of polymer for surfactants.These effect are important from the analytical point of view.For high frequencies or under potentiometric conditions surfactants do not interfere with ions concentration determination.On the other hand,for low frequencies surfactants interactions with PPyCl membrane give rise to analytically useful signal.The linear dependencies of current on logarithm of surfactant concentration were obtained within the concentration range at least from 10~(-7) to 10~(-4) mol/dm~3.