Development of an Ion Exchange Membrane Characterization Protocol

Abstract

The development of electrochemical devices for electric energy generation has been in constant growth in recent years because environmental challenges provide a driving force for many of today’s studies of electrochemical materials [1], among these are destacable: fuel cells, reverse electrodialysis cells, redox flow batteries, bio electrochemical systems (microbial fuel cells), etc. A key component in the behavior of all of them is the ion exchange membranes, which have high commercial value, so in the development of these technologies the need for local production is presented to make their application cheaper, so its complete characterization is required to determine if they are applicable in these technologies. This paper presents the experimental protocol developed and the results of its application to the membrane characterization of Nafion® 117, material of extended use and which its properties are widely known, in order to validate the methodology proposed with the existing literature . The characterization consists in a series of laboratory tests that deliver the most important properties of the membrane. Initially a pre-treatment of the membrane is carried out to bring it to a reproducible condition and then its properties are measured as conductivity both by a voltammetric method with controlled current and by electrochemical impedance; electroosmotic drag coefficient from measurement of potentials [2], [3], permeability to substances such as ethanol; and thermal stability. It is expected that the proposed protocol and the results obtained will be useful in the characterization of membranes, both protonic and anionic, that are currently being developed in multiple universities and educational centers around the world, as well as at the Universidad Nacional de Colombia - Sede Medellín, to make competitive these energy production technologies that use this type of solid electrolyte [4], [5].