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In this work the authors explore the use of electrochemical impedancespectroscopy (EIS) as a tool for characterizing membrane surface chemistry. The surfacepotentials of iron-based and aluminum-based nanostructured ceramic membranes werecharacterized using EIS, and compared with measurements of electrophoretic mobilityand acid/base titration. Protonic conductivity was measured using EIS in a two-electrodemode at a frequency range of 0.01 Hz to 100 kHz. Electrophoretic mobilitymeasurements were performed at various ionic strength and pH for suspended ceramicnanoparticles sintered at different temperatures. The isoelectric point determined fromelectrophoretic mobility measurements and from titration methods were compared. Theisoelectric point of membranes sintered at different temperatures agrees with the protonicconductivity measurement by EIS. Membranes with lower isoelectric point correspond tomore surface hydroxyl groups available for proton transfer, which enhances its protonicconductivity. EIS is a simple and reliable method of providing information about thesurface potential of ceramic membranes without damaging the membrane sample. Includes 2 references, figures.

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Edition: Vol. - No. Published: 03/01/2005 Number of Pages: 4File Size: 1 file , 310 KB