Surface Modification of Polyaniline Films with 4-Alkyl- and 4-Perfluoroalkylanilines
Hanks, T. W.; Powell, M.; Gregory, R. V.; Wright, L. L. Surface Modification of Polyaniline Films with 4-Alkyl- and 4-Perfluoroalkylanilines. In Conferences Proceedings at ANTEC '98: Plastics on My Mind: Atlanta, GA, 1998; Vol. 44, pp 1325-1329.
Cast films of ES PANI were dipped in 1M solutions of either 4-dodecylaniline or 4-perfluorohexylaniline for 30 minutes. Color changes in the films indicated that the polymer was slowly dedoped under these conditions, but no precipitation of new polymer could be observed. This behavior is consistent with cyclic voltammetry studies of the substituted anilines in which oxidation led to dimer formation rather than polymerization. The films were washed with water and then with acetone to remove absorbed species. In some cases, the films were scrubbed with tissue paper to ensure complete removal of absorbates; Contact angle analysis of the treated films showed that the surfaces had become much more hydrophobic and less polar. While only minor changes in the dispersive component of the surface energies were observed, the polar component was greatly decreased on going from unmodified to dodecyl-modified to perfluorohexyl-modified films. AFM studies showed that the substituted anilines grew on the film surface as small islands, approximately 40 nm in diameter and 10-15 nm high. Phase data from tapping mode experiments showed these islands to be "softer" than the original film. Force curve analysis showed the islands to be less adhesive than the original film, consistent with the contact angle data.
Conferences Proceedings at ANTEC '98: Plastics on My Mind