Novel lamellar nanocomposites composed of exfoliated SbP2O8- nanosheets and poly(N-methyl-2-ethynyl pyridinium iodide) (PNMe) or poly(N-octadecyl-2-ethynyl pyridinium bromide) (PNO) have been synthesized by exfoliation and re-stacking method. The XRD data of the nanocomposites SbP2O8-:PNMe and PNO:SbP2O8- indicate the formation of nanostructures containing SbP2O8- nanosheets and PNMe or PNO with interlayer expansions of 2.22 and 4.2 nm along the stacking direction of SbP2O8- nanosheets. formation of these nanocomposites is further supported by the results obtained by FT-IR spectroscopy, scanning transmission electron microscopy and thermogravimetry. The values of electrical conductivity of the polymers and nanocomposites have also been measured. (c) 2005 Elsevier Inc. All rights reserved.