Pairing electrochemical impedance spectroscopy with conducting membranes for the in situ characterization of membrane fouling

Protein fouling within a polymeric microfiltration membrane was characterized in situ and in real time with non-Faradaic electrochemical impedance spectroscopy (EIS). The polymeric membrane was prepared with a conductive gold coating, allowing the membrane surface to serve as a working electrode in a three-electrode EIS system. Utilizing the membrane surface as the working electrode allowed for differentiation between internal and external contributions to fouling. Protein fouling was able to be monitored qualitatively by observing changes in the resulting Bode and Nyquist plots and quantitatively by modeling the electrochemical system with equivalent circuit components comprised of resistive and capacitive elements. To our knowledge, this work represents the first attempt to deploy a conductive polymeric membrane as an active electrode in an EIS setup.