Poly(3,4-ethylenedioxythiophene)/poly(styrene-4-sulfonate) (PEDOT/PSS) comp
osites have been prepared from aqueous and aqueous acetonitrile solutions o
f EDOT and NaPSS by oxidation using Fe(III) salts. Powders with PEDOT to PS
S ratios ranging from 0.3 to 4.2 and electronic conductivities as high as 1
0 S cm(-1) have been obtained in good yields. The PEDOT/PSS blends are cati
on exchangers and exhibit facile electrochemistry in both aqueous and aceto
nitrile media. Impedance measurements have shown that 30 mu m thick PEDOT/P
SS layers have proton conductivities as high as 0.03 S cm(-1).