Au@AOT films with adjustable roughness, controlled wettability and plasmon effect

Abstract

Au@AOT composites based on the diluted concentrates of the metal nanoparticle organosols were obtained by the chemical bath deposition method. The polystyrene with the smooth surface was applied as the substrates. The Au particle sorption time was varied in the range of 0–6 days. The optimal surfactant concentration in the sol (4.2 10 −3 M) allowed one to carry out the sorption of particles at the fixed deposition rate (1.4 particles·μm −2 ·day −1 ). It was experimentally shown that the surface and optical properties of Au@AOT films depended on both the numerical concentration and the linear dimensions of Au particles. The sorption time variation allowed one to obtain the samples with the adjustable root-mean-square roughness (from 1.9 ± 0.3 to 9.6 ± 0.8 nm), the contact angle (from 95 ± 3 to 31 ± 3˚) and the absorption intensity (from 0 to 0.115). All samples exhibited a plasmon effect and maintained stability in the working liquid medium. The synthesized Au@AOT composites could be used for the optical sensor applications. • A way to creating gold composites with controlled surface properties was proposed. • The properties of gold composites depend on the size and number of metal particles. • The obtained composite gold films have a plasmon effect. • A plasmon effect saves in composite gold films after multiple liquid contacts. • The energy parameters of composite gold films and gold particles were estimated.