Polyaniline was created utilizing compressed co2 as a medium for the polymerization process; aniline aqueous solution with an addition of acetic acid (few amount to completely dissolve the aniline) and APS as an oxidization agent?
If the final product has poor washed out - this vibrations of the carbonyl group. The 3400 cm-1 must be a hydroxyl group oscillation signal. Although they may overlap signal vibrations NH2 group, if the polymer chain contains these groups