PREPARATION AND CHARACTERIZATION OF SILVER NANOROD FILMS: COMPARING TWO-DIMENSIONAL SELF-ASSEMBLY OF HEXADECANETHIOL-CAPPED SILVER NANORODS AND OCTANETHIOL-CAPPED SILVER NANORODS
Abstract
Interactions in synthetic metal nanorod assemblies are able to introduce interesting optical, magnetic, mechanical and catalytic properties to a particular system. Controlling the quality of two-dimensional self-assemblies and the distance between nanoparticles are therefore essential to the fabrication of next-generation nanodevices such as plasmon waveguides, biosensors, and ultrahigh density data storage media. We demonstrate that side-by-side assembly of alkanethiol-capped silver nanorods can be achieved in a solvent-mediated process under appropriate conditions. The factors affecting the formation of nanorod monolayer such as nanorod concentration, sonication duration, solvent and
substrate used have been identified and optimized. Furthermore, we report successful spatial control in self-assemblies of silver nanorods capped by different chain lengths of
alkanethiol. Interparticle distances of hexadecanethiol-capped silver nanorods and octanethiol-capped silver nanorods (aspect ratio ~50) have been measured. The reported spacing between octanethiol-capped silver nanorods agrees with the theoretical value, whereas the spacing between hexadecanethiolcapped silver nanorods is smaller than expected. This observation can be explained by greater conformational defects in the hydrocarbon tails that increase with chain length.
Description
Keywords
Nanorod, Self-assembly, Nanotechnology, Nanoscience, Sonication, Electron microscopy, Interparticle distance