Fabrication of self-assembled polyaniline films by doping-induced deposition

The ultrathin films of polyaniline (PAni)/poly (styrenesulfonic acid)(PSSA) were fabricated via a novel self-assembling process by alternately immersi ng the substrates into dilute PAni solution in N-methylpyrrolidinone (NMP) and the aqueous solution of PSSA. The process was characterized by W-Vis ab sorption spectroscopy. It was found that the oxidation state of polyaniline in single monolayers was dependent on the thickness of the film. The self- assembling mechanism was based on the acid-base reaction between PAni and P SSA. The thickness of the films can be easily manipulated at nanometer scal e by controlling the solution chemistry and recycling times. The resulting films are uniform and adhere strongly to the substrates. (C) 2000 Elsevier Science S.A. All rights reserved.