In this work, polyaniline/poly(sulfonated styrene) (PANI-PSS) nanofiber composites were prepared by an interfacial method. The in situ polymerization technique of these PANI nanofibers in the presence of sulfonated polystyrene allowed for the growth of PANT 2-D nanostructures embedded in the polymerized sulfonated host. This facile approach enables a self-assembly of these nanofibers into a workable, robust, conductive composite which can be processed and cast from water. A low accelerating voltage scanning electron microscopy (SEM) was used to image these twisted fibers within the bulk of the cast film. In addition, the SEM confirmed the self-assembly of these 40-50 nm fibers within the host PSS to yield an electrically conducting composite film. (C) 2004 Elsevier B.V. All rights reserved.