Doping of 2-Cl-PANI/PVC films by exposure to UV, gamma-rays and e-beams

2-Chloro-polyaniline (2Cl-PANI) is chemically prepared in its non-conductin g (Emeraldine Base, EB) form and dissolved together with polyvinylchloride (PVC) in THF for casting into thin (10-50 mu m) composite films. The electr ical conductivity of these films increases by more than four orders of magn itude (from 10(-6) to 10(-2) S/cm) when they are exposed to UV, gamma-rays and e-beams. This is attributed to the dehydrochlorination (loss of HCl) of PVC by exposure to energetic particles and subsequent doping of the 2-Cl-P ANI (i.e., conversion to Emeraldine Salt, ES) by the in-situ-created HCl. T he doped films can also be returned to their undoped form by further exposu re to NH3 vapours. The UV (or other particles)-induced doping/NH3 undoping cycles can be repeated several times until almost total dehydrochlorination of the PVC matrix. UV-Vis-NIR, Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopic (XPS) techniques are employed to follow the ch anges in the composite films upon doping by exposure to these energetic par ticles. (C) 2000 Elsevier Science S.A. All rights reserved.