Silver emulsion films with isotropic mechanical properties and hydrophilic porous surface

Optically active films based on Ag nanoparticles stabilised by sodium bis(2-ethylhexyl)sulfosuccinate (AOT) were prepared by the dip-coating method. It was experimentally found that variation of the substrate immersion number allowed one to control the surface properties of the prepared films. The values of the surface roughness, the pore depth, the contact angle, and the adhesion work vary within a wide range from 1.1 ± 0.5 to 20.9 ± 1.7 nm, 25±6 to 37±7 nm, 37±4 to 18±5°, and 2.5 ± 0.1 to 32±1 J∙m^-2, respectively. A comprehensive study using X-ray energy dispersive analysis, X-ray photoelectron spectroscopy, and UV–Vis spectroscopy showed that the prepared films exhibited a complex chemical composition. The films are formed by the silver nanoparticles encapsulated in the AOT layer. The numerical concentration and the linear size of the encapsulated nanoparticles grow with an increase of the substrate immersion number. Due to the presence of hydrophilic properties as well as a stable plasmonic effect, the obtained films can be considered as a promising material for the development of surface plasmon resonance sensor devices with liquid contact.