Variation of ac electrical properties of emeraldine base of polyaniline during its drying from suspension in m-cresol

The variation of electrical properties of the emeraldine base form of polyaniline during its transformation from a suspension in m-cresol to the dry state was studied in situ, employing electrical impedance measurements at 30 degrees C in a wide range of frequencies (10(-2)-10(5) HZ). The obtained results were fitted using the equivalent electrical circuit with the elements corresponding to different physical processes in the polymer/solution system. The PANI-EB suspension was approximated by a Randles-type equivalent circuit containing an additional element responsible for the a.c. conductivity in the bulk polymer. During the drying of PANI-EB the configuration of the equivalent circuit was consistently changed from the electrochemical one to that corresponding to the dry polymer. The assumption is put forward that a double layer presented at the polymer/electrolyte interface is transformed into surface states in a dry polymer.