Electrical conductivity of polyaniline as a function of pressure using a diamond anvil cell

We report our results on the electrical resistance of thin films of polyaniline as a function of pressure which was applied to the samples using a diamond anvil cell up to 22 GPa at room temperature. Samples of polyaniline cast from N-methylpyrrolidinone (NMP) and doped with HCl and also those doped with camphor sulfonic acid (CSA) and cast from m-cresol were studied. Resistance versus pressure measurements recorded during the loading and unloading cycle show asymmetry, suggesting irreversible structural changes. Since the primary effect of applying pressure is sample compression, this leads to reduced interchain separation resulting in enhanced interchain charge transport. Such effects are reflected in reduced resistance with increasing pressure as depicted in our results.