چكيده لاتين :
The response mechanism of polyaniline to a selection of gases and vapours was
investigated by measuring its conductance and mass changes by using a fourprobe
method, elemental analysis, and X-Ray fluorescence (XRF) technique. The
prepared films were exposed to hydrogen halides, hydrogen cyanide, hydrogen sulphide,
halogens, acetic acid, rnono-, di-, and trichloroacetic acid, formaldehyde, hexachloroacetone,
1,3,5-trichloromethyl benzene, methyl benzyl bromide, bromoacetone and
cyanogen bromide. It is observed that the polyaniline conductance changes are partly
due to two-stage sorption perhaps involving the swelling of the polymer and gas diffusion.
All the films were exposed to dilute ammonia solution or vapours of organic solvents and
swelled before doping, which could modify the mass and electrical measurements. It was
demonstrated that slightly additional amounts of Hel gas in tested gases will significantly
influence the conductivity. It is concluded that the response mechanism of polyaniline
sensing of different gases and vapours is due to a mixed response involving electronic
and physical effects.
