Sensitivity of the electrical admittance of a polysiloxane film to organicvapours

The sensitivity of polycyanopropylmethylsiloxane films to organic vapours h as been investigated using electrical admittance spectroscopy. The films we re exposed to benzene, ethanol and acetonitrile. In all cases, a reversible change in the capacitance and conductance of the polymeric film was observ ed. An analysis of the changes induced by the different vapours suggests th at, with a judicious choice of measurement frequencies, conductance and cap acitance data could provide an useful basis for a selective sensing system. (C) 1999 Elsevier Science S.A. All rights reserved.