Synthetic opals made by the Langmuir-Blodgett method

Monodispersive synthetic opal particles were formed by the method of Stober et al. [J. Colloid Interface Sci. 26 (1968) 62] and were made hydrophobic by reacting them with 3-(trimethoxysilyl)propyl methacrylate. Groups of particles were dissolved in chloroform and were spread at the air/water interface using a Nima trough. Each group studied consisted of particles, which had almost identical diameters. Isotherms were obtained and these are illustrated. The use of an optimum value of surface pressure and a high level of hydrophobicity made it possible to deposit good quality multilayers by the Langmuir-Blodgett method but we found that the Langmuir-Schaefer method was easier to use for less hydrophobic particles. The layers obtained were studied by scanning electron microscopy and we present the images obtained from these results.