281 J. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Electroanal. Chem., 220 (1987) 281-294 Elsevier Sequoia S.A., Lausanne - Printed in The Netherlands zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQ ELECI’ROCHEMICAL S-IS AND STUDY OF POLYDIPHENYLAMINE UMAR HAYAT, PHILIP N. BARTLETT and GEORGE H. DODD Department of Chemistry, Universiq of Warwick, Coventry, CV4 7AL (Great Britain) JOHN BARKER Department of Electronics and Electrical Engineering University of Glasgow, Glasgow (Great Britain) (Received 23rd May 1986; in revised form 6th November 1986) ABSTRACT The electrochemical oxidation of diphenylamine in acetonitrile produces an adherent conducting polymer film at the electrode. Conductivity measurements on pressed pellets of this polymer give a room temperature conductivity of 10 S cm-‘. The polymer can be cycled between 25 and 2OO’C without deterioration in the conductivity. Preliminary SEM/EDS studies suggest that there is one BFi counter ion for every four monomer units in the oxidised polymer film. INTRODUCTION zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA The preparation of conducting polymers is an active area of both academic and industrial research because of the interesting properties displayed by these materials [l-8]. Electrochemical polymerisation is a useful method for the preparation of these materials because it is an essentially reagentless process and can be readily controlled [9-111. Our interest in the development of gas sensors based on conducting polymers, formed by the electrochemical polymerisation of substituted aromatic amines, has led us to investigate the electrochemistry of diphenylamine. Whilst the electrochem- ical polymerisation of aniline and a number of its derivativeshas been the subject of much recent interest [12-151 there are, to the best of our knowledge, no reports in the literature of the electrochemical polymerisation of diphenylamine. Previous studies of the polymerisation of aromatic amines have shown that on electrooxida- tion they undergo rapid head-to-tail coupling [16-201. This type of coupling is, however, unlikely to occur with diphenylamine because of steric crowding. 0022-0728/87/$03.50 0 1987 Elsevier Sequoia S.A.