Novel self-assembled micro/nanostructured polyaniline-clay nanocomposite (PANICN) materials were prepared by in situ intercalative emulsion polymerization of aniline in aqueous dispersion of clay using functionalized amphiphilic dopant, 3-pentadecyl phenyl phosphoric acid (PDPPA) derived from renewable resource. The structural effect of PDPPA on the morphology, electrical conductivity and phase transition temperature of PANICNs was compared with nanocomposites prepared using dodecyl benzene sulphonic acid (DBSA) and HCl. X-ray diffraction and scanning electron microscopic (SEM) studies revealed the formation of monolayer of protonated PANI intercalated nanoclay layers with template polymerized self-assembled micro/nanostructured PANI on the surface of the clay. Nano/microstructured PANIs were formed by the supra-molecular self-assembling of the inter-chain hydrogen bonding, interplane phenyl stacking and electrostatic layer-by-layer self-assembling (ELBS) between polarised alkyl chains present in dopant anions and were manifested using Fourier transform infrared spectroscopy and differential scanning calorimetry. (c) 2006 Elsevier Ltd. All rights reserved.