Poly(o-anisidine) Langmuir-Schaefer films: Fabrication and characterization

The effect of pH on the Langmuir monolayer behavior was investigated for the poly(o-anisidine) (POAS) conducting polymer. The Langmuir-Schaefer (LS) films were prepared at pH 1 of the subphase, where the doping during the monolayer formation was essential for the high quality of the conducting polymer film. The LS films of POAS were characterized by using Fourier transform infrared spectroscopy, W-vis absorption, X-ray diffraction, and ellipsometry techniques. The thickness of one monolayer of POAS film was estimated to 24 Angstrom by using X-ray reflectivity and ellipsometric measurements. The uniformity of such POAS LS films was investigated for the redoping in 1 M HCl (protonic acid) for achieving the higher conductivity. The conductivity of the POAS LS film was shown to vary between 0.1 and 10(-9) S/cm. Direct current through conducting LS films of POAS was observed as a function of monolayers. Further, the effects of different protonic acids on the electrical behavior of the POAS LS films were also investigated at length.