Meh. Amrani et al., HIGH-FREQUENCY MEASUREMENTS OF CONDUCTING POLYMERS - DEVELOPMENT OF ANEW TECHNIQUE FOR SENSING VOLATILE CHEMICALS, Measurement science & technology, 6(10), 1995, pp. 1500-1507
Electrically conducting polymers have previously been used for the det
ection of vapours and gases by measuring the reversible change in thei
r DC resistance. The sensors have very broad chemical specificity with
higher sensitivity to polar chemicals. The change in the AC impedance
characteristics of poly-N-(2-pyridyl)pyrrole in the presence of three
different volatile chemicals was investigated, in order to determine
whether measurement of multifrequency parameters could be used as the
basis of chemical discrimination. The results demonstrate quantificati
on of concentration and discrimination between the chemicals tested on
the basis of capacitance, conductance, resistance and dissipation fac
tor as a function of frequency. This technique may be generally applie
d for discrimination between many chemical species.