Hands-On Laboratory Class for Electrochemical Impedance Spectroscopy Characterizing Membrane Pore Structure

Electrochemical impedance spectroscopy (EIS) is a rapid and powerful method for evaluating the pore structure of membranes. However, the application is limited due to the lack of appropriate training of engineers in electrochemistry and materials engineering. The introduction of laboratory practices can effectively improve the understanding of electrochemistry and the theory behind the various applications. In this paper, we suggest a laboratory experiment on the characterization of the pore structure in a membrane by EIS. The membrane resistance was obtained from the impedance spectrum, and the correlation between the membrane resistance and water flux of the membrane is discussed. Moreover, the influence of the electrolyte concentration on the EIS result was also investigated in the designed experiment. Students are trained to collect the impedance spectra of the membrane under different conditions and learn to understand the effects of the operating parameters (electrolyte concentration and pore size) on the impedance spectrum. This laboratory class allows undergraduate students to better understand the principle of impedance spectroscopy on membrane characterization.