Nanostructural Characterization of Gold Nanorod Assemblies in Hexagonal Liquid Crystalline Template

Abstract

Exploiting the unique anisotropy and fluidity of liquid crystals (LCs) enables the design of advanced hybrid nanomaterials for photonic applications. The intrinsic long-range order of the LCs matrix can act as a structural template, directing nanoscale dopants into well-defined geometrical configurations and enabling precise control over nanoparticle distribution. Here, we use an inverted hexagonal phase (H2) of sodium bis(2-ethylhexyl) sulfosuccinate (AOT), p-xylene, and a water dispersion of gold nanorods (AuNRs) to fabricate well-ordered nanomaterial assemblies. Scanning transmission electron microscopy of thin films reveals AuNR chains extending up to 30 μm in length with a mean interparticle spacing of about 5 nm and a 2D order parameter S2D = 0.96 ± 0.10. Correlative multiphoton and polarizing microscopy demonstrate a uniform arrangement of AuNRs within the central region of the sample thickness, particularly at the domain boundaries. The performed nanostructural characterization suggests the ordering mechanism and highlights the impact of anchoring forces on nanorod ordering and microstructure formation in the bulk sample.