Polystyrene/layered silicates nanocomposites were prepared by intercalation in solution method, using CHCl3 and CCl4 as solvents. The clay used was organically modified by hexadecyltrimethyl-ammonium bromide (CTAB) at various surfactant loadings. It was found that intercalated nanocomposite structure was obtained using CHCl3 as solvent while exfoliated or partially exfoliated was the predominant form in the case Of CCl4, X-ray diffraction and thermogravimetric analysis were used to characterize the nanocomposite morphology and thermal stability, respectively. Enhancement in thermal stability was observed for PS-nanocomposites compared to that of pristine polymer as indicated by TGA measurements. This increment was more prevalent for exfoliated nanocomposites prepared with carbon tetrachloride as solvent. (C) Koninklijke Brill NV, Leiden, 2009