new method was used to synthesize the PbS nanoparticles in polystyrene matrix. Absorption spectra

small angle x-ray scattering(SAXS) and TEM were utilized to characterize the average particle size and the size distribution.The amount of H2S and the initial concentration of Ph2+-containing copolymer affect on nanoparticle size slightly

but greatly for the particle size:distribution. The distribution is getting broad as increasing the concentration of H2S and the Pb2+-containing copolymer. The reaction conditions during the formation of the PbS nanopar--rticles in solution determine the size distribution. The bulk polymerization process has little effects on it. By controlling the reaction conditions properly

an organic optical composite with good transparence was obtained

in which the PbS nanoparti-cles with a narrow particle size distribution were well dispersed.