Self-assembly of alkane capped silver and silica nanoparticles

Silver and silica nanoparticles stabilised by long chain alkanes have been prepared and characterised using H-1-NMR, transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS). Upon solvent evaporation, the alkane stabilised silica and silver nanoparticles self-assemble into close-packed two-and three-dimensional structures. Furthermore, it is shown that a mixture of large silica (90 Angstrom) and small silver (48 Angstrom) nanoparticles self-assemble into mixed well-defined close-packed structures. It has been demonstrated that particle size, core material and solvent composition can be employed to control the forces between individual nanoparticles and, consequently, the structure of the self-assembled arrays. These mixed structures have also been studied using UV-visible spectroscopy and their collective optical properties are shown to depend on their overall composition.