Langmuir-Blodgett films of alkanethiolate gold nanorods

Colloidal multilayers of octadecanethiol-capped Au nanorods were prepared using the Langmuir-Blodgett technique. Uniform growth of the films with increasing number of deposition has been observed. Vertical transfer efficiency indicates efficient transfer for immersion of hydrophobic substrates and poor transfer for emersion of such substrates. The vertically transferred film has an order parameter S = 0.027, which suggests that the orientation of the nanorods in the film is somewhat isotropic about the dipping direction. Horizontal transfer of the Langmuir monolayer on Formvar/carbon-coated Cu grids, however, gave scattered domains of Au nanorods aligned in parallel stacks. Such behavior is probably related to the rigidity of the Langmuir monolayer.