Large Area Self-Assembly of Nematic Liquid-Crystal-Functionalized Gold Nanorods

Fascinating nematic- and smectic-like self-assembled arrays are observed for gold nanorods partially capped with either laterally or terminally attached nematic liquid crystals upon slow evaporation of an organic solvent on TEM grids. These arrays can be manipulated and reoriented by applying an external magnetic field from quasi-planar to vertical similar to a Freedericksz transition of common organic nematic liquid crystals. Birefringence and thin film textures of these self-assembled gold nanorod arrays observed by polarized optical microscopy are strongly reminiscent of common organic nematic liquid crystal textures between crossed polarizers and, additionally, support the formation of ordered liquid crystal-like anisotropic superstructures. The ordering within these arrays is also confirmed in bulk samples using small angle X-ray scattering (SAXS).