Gold nanorods: Influence of various parameters as seeds, solvent, surfactant on shape control

In this paper we demonstrate that better-defined Au nanorods are obtained by using fresh and pseudo spherical seeds. Furthermore, the 30-day aged nanorods dispersed in aqueous solution are characterized by a narrow size distribution. Addition of ethanol induces attraction between particles with a change in the refractive index giving a change in the optical properties. Addition of chloroform to water–ethanol solution induces aggregation with the total disappearance of the resonance plasmon mode of nanorods. The key of the oriented growth gold nanorods is the relative ratio of cetyltrimethylammonium bromide surfactant (CTAB), silver ions and seeds is a key parameter for producing well-defined Au nanorods.