I have deposited Polyaniline on sulfonated PEEK membranes through In situ solution polymerization. I want to calculate electrical conductivity using Gamry Potentiostat.
Hi Muhammad,
to measure the surface conductivity of the polyaniline coated membranes I think you should build up a system similar to a four point probe. You could set up a system with four parallel needles (separated from the same distance) to push on the coated membranes. Then, you should impose a defined potential to the external needles while measuring the current flowing through the central ones. If you repeat these measurements imposing various potentials you could obtain a characteristic curve. The slope of its linear part is correlated to the material surface conductivity by the needles distance through the Ohm's first law. To quantify the needles parameters you can calibrate the instrument over a known conductivity surface.
I hope I have been clear. Good work and good luck.
Giulio.
Hi Muhammad,
to measure the surface conductivity of the polyaniline coated membranes I think you should build up a system similar to a four point probe. You could set up a system with four parallel needles (separated from the same distance) to push on the coated membranes. Then, you should impose a defined potential to the external needles while measuring the current flowing through the central ones. If you repeat these measurements imposing various potentials you could obtain a characteristic curve. The slope of its linear part is correlated to the material surface conductivity by the needles distance through the Ohm's first law. To quantify the needles parameters you can calibrate the instrument over a known conductivity surface.
I hope I have been clear. Good work and good luck.
Giulio.
If your resistance is high in kilo ohms and above, you can go for two terminal measurement also instead of four terminal measurements suggested above. For this purpose make good electrical contacts at two places on your film and measure current at an applied voltage. If you are in megaohms resistance range and above, mount your film in a metallic sample holder with vacuum inside for electromagnetic shielding.
a 4-point probe can only be used in case of reasonably high conductivity, should be at least 10^-4 S/cm. I assume you may have a lower conductivity, so I recommend to use a so-called ring electrode for measurement of surface conductivity / resistivity (you can find in the web what this is)
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