APPLICATION OF IN-SITU UV-VIS SPECTROSCOPY AND AN IN-SITU DC RESISTANCE MEASUREMENT TECHNIQUE TO THE STUDY OF A POLY(THIOPHENE-3-METHANOL) FILM

The evolution of the UV-vis optical absorption of poly(thiophene-3-met hanol) (PTM) has been followed as a function of applied potential in B u4NClO4 and Bu4NPF6 in acetonitrile. The UV-vis spectra at 310 to 820 nm show similar features to many polythiophenes of higher degrees of c onjugation. The behaviour of the absorbance maxima corresponding to in terband transition and (bi)polaron bands have also been registered dur ing linear sweeps and potential step measurements in order to characte rize the response of the PTM to applied potential, and the recovery of the polymer film during reduction. The evolution of the absorbance sh ows differences in the behaviour of the films synthesized and studied in the presence of the two anions. These correlate with our previous i n situ FTIR measurements. The study of a conductive polymer by the new ly developed contact electric resistance (CER) technique is reported f or the first time. This in situ de resistance measurement technique ha s been applied for determining the behaviour of the resistance of PTM during linear sweep measurements as well as for estimation of the maxi mum conductivity of the PTM, which was about 10(-4) S/cm. The results obtained by UV-vis spectroscopy and CER technique are compared. (C) 19 97 Elsevier Science S.A.