Atomic force microscopy investigations of morphologies in ultrathin polyaniline films

Preliminary results of two studies of the morphology of polyaniline, studied by means of atomic force microscopy (AFM), are reported. (1) Emeraldine base (EB)/camphorsulfonic acid (CSA) highly oriented fibers were prepared by a ‘hot-drawing’ technique. In addition to imaging the drawn fibers themselves, within the fibers, an internal structure with a clear orientation in the drawing direction is observed. (2) Submonolayer coverages of EB/CSA spin-coated from a chloroform solution onto highly oriented graphite (HOPG) were studied, and geometrically shaped crystalline islands are observed. The internal structure of these islands is attributed to the presence of compact coils. Morphological changes upon ‘secondary doping’ using m-cresol vapor were studied. Upon secondary doping, the crystallinity is lost.