Electrical and morphological characterization of poly (monosubstituted)acetylene based membranes: application as humidity and organic vapors sensors

The responses of resistive-type sensors based on two poly(monosubstituted)acetylenes, namely poly(N,N-dimethylpropargylamine) (Pd-PDMPA) and poly(propargylalcohol) (PPOH), to relative humidity (r.h.%) and to alcohol vapors were investigated. The polymeric materials Pd-PDMPA and PPOH were doped with HCl or with SnCl2 and I2, respectively.HCl-doped Pd-PDMPA exhibited detectable response to r.h. percentages as low as 2% and a variation of five orders of magnitude in the r.h. range 0 – 90 %. PPOH doped with SnCl2 or I2 varied its conductivity of about four orders of magnitude in the full range of r.h.. Both doped polymers showed sensitivity to methanol. A morphological characterization was carried out in order to correlate the differences in the electrical behavior.