Nanostructured silica Langmuir-Blodgett films with antireflective properties prepared on glass substrates

Mono- and multiparticulate nanostructured silica films were prepared by the Langmuir-Blodgett (LB) technique both from hydrophilic and hydrophobic Stöber silica nanospheres of 92 and 107 nm diameters. The effective refractive index and the film thickness were determined from the transmission spectra (300-1200 nm) by evaluating interference peaks and parameter fitting. The spectra were notably different depending on particle sizes, number of layers transferred, and particle hydrophobicity. The monolayers showed expressed antireflection properties. From the film thickness values obtained for multiparticulate LB films we came to the conclusion that the particles arrange themselves in a close-packed array during the preparation of LB films.