Aniline molecules were polymerized and formed polyaniline (PANI) on multiwalled carbon nanotubes (MWCNTs) by using plasma induced polymerization technique. The PANI modified MWCNTs (PANI/MWCNTs) composites were characterized by using ultraviolet-visible spectrophotometry, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis-differential thermal analysis (TGA-DTA), field-emission scanning electron microscopy (FE-SEM), and vibrating sample magnetometer (VSM). The results indicated that the PANI/MWCNTs magnetic composites were synthesized. The application of PANI/MWCNTs magnetic composites for the removal of Pb(II) from aqueous solutions was investigated under ambient conditions. The modified PANI on MWCNT surfaces contributed to the enhancement of MWCNT adsorption capacity because the amine and imine functional groups of PANI have strong affinity with Pb(II) ions. PANI/MWCNTs magnetic composites can be separated and recovered from aqueous solution by simple magnetic separation. The results show that PANI/MWCNTs magnetic composites are promising magnetic materials for the preconcentration and separation of heavy metal contaminants from large volumes of aqueous solutions in environmental pollution cleanup. (c) 2012 Elsevier B.V. All rights reserved.