On the porosity of polypyrrole films

Polypyrrole (PPy) films doped with anions of various size, charge and chemical nature (inorganic, surfactant, with aromatic ring) were electrochemically synthesized and investigated by low-temperature N-2 sorption experiments at -196C. The specific surface area, total pore volume, average pore radius, pore size distribution and other parameters for oxidized PPy films using dodecylsulfate, 2-naphthalene sulfonate, 1,5-naphthalene disulfonate, poly(4-styrenesulfonate), tosylate, perchlorate, nitrate and chloride as dopant ions, were calculated. The obtained data show that although the average pore radius of investigated mesoporous PPy films (17-19 angstrom) is practically independent of the dopant anion used, however the latter determines the total pore volume and specific surface area values in different PPy materials investigated. As the total pore volumes for PPy films doped with large amphiphilic anions show the smallest values, the corresponding values for PPy/small inorganic anions, are up to 2 times higher. (c) 2007 Elsevier B.V. All rights reserved.