Growth and assembly of monodisperse Ag nanoparticles by exchanging the organic capping ligands

Nearly monodisperse Ag nanoparticles capped with octadecylamine were prepared by direct thermal decomposition of silver nitrate in octadecylamine. Then the “oriented attachment” assembly process of these monodisperse nanoparticles was exhibited by exchanging the organic capping ligands, and Ag short nanorods capped with dodecanethiol could be obtained as a result. The composition of Ag was analyzed by x-ray diffraction, and the morphological change from nanoparticle to short-nanorod was examined by transmission electron microscopy. Moreover, we also propose a probable mechanism for this transformation process.