Conducting polyaniline (PAni)/activated carbon (AC) nanocomposites were synthesized by the in situ chemical polymerization method. The resultant shell-core PAni-AC nanocomposites were characterized by elemental analysis, Fourier transform infrared, scanning electron microscopy, thermal gravimetric analysis, X-ray diffraction, and transmission electron microscopy. We did not observe any significant chemical interaction between the PAni and AC, only core-shell coupling between the AC and the tightly coated polymer chain was revealed. Measurement of the physical properties showed that the incorporation of conducting PAni on to AC particles during chemical synthesis increased electrical conductivity and thermal stability by several orders of magnitude to that of the pristine PAni powders. (c) 2006 Wiley Periodicals, Inc.