X-ray photoelectron spectroscopy study of electrically conducting polyaniline/polyimide blends

The changes in protonation level ([N+]/[N] ratio), doping state, and conjug ation condition for polyaniline-complexes/polyamic acid (PANI-complexes/PAA ) blends and their thermally cured polyaniline-complexes/polyimide (PANI-co mplexes/PI) have been assessed by X-ray photoelectron spectroscopy and W-Vi s spectroscopy. It was suggested that the protonation levels were predomina ntly associated with dopants that show different protonation ability. By XP S N1s peak convolution, it was found that thermal treatment of blends led t o dedoping when the curing temperature reached 250 degrees C. However, stab ility of protonation state of blends against thermal curing was higher than pure PANI-complexes. Dopants in the blends also affect the distribution of N+ species and thermal stability to curing. Mild thermal treatment (180 de grees C) led to the increase of conjugation length ascribing to the increas ed order of polymer chain, although their protonation levels were not incre ased. (C) 2000 Elsevier Science Ltd. All rights reserved.