Atomic force microscope studies of the ultrathin polystyrene/silica composite film formation on mica

Abstract

The elucidation of organic-inorganic hybrid materials at nanolevel is now widely investigation. One of the most promising ways of making such materials utilizes the surfactant template technique. This research focused on polystyrene/silica film formation on mica both with and without the presence of surfactant and the characterization of the films by atomic force microscopy (AFM). Octyl phenol ethoxylate (Triton X-100) was used as self-assembly structures of nonionic surfactant on mica and the reactants included: tetraethyl orthosilicate (TEOS) as an inorganic monomer, styrene as an organic monomer, and 1, 2'-azobisisobutyronitrile as an initiator in de-ionized water. In system without surfactant, there was no significant polystyrene structure fourmed on the mica and the surface characteristics of the films, which exhibited multigranular features scattered across the surface, did not differ from one another. The surface morphology of the films was dramatically affected by the presence of surfactant. Styrene and TEOS concentrations strongly affected the film structure on the mica. Styrene and TEOS at concentration of 3 um behaved synergistically in the formation of polystyrene/silica films on mica. These films were dense and highly compacted, being well-connected between periodic structures in which vacant or empty spaces and loose aggregates werte absent.