POLYMER LANGMUIR-BLODGETT-FILM OF ORGANIC-INORGANIC (FE2O3) COMPOSITE MICROGEL

Methylacrylic acid was used as a surfactant to prepare Fe2O3 organosol by the microemulsion method in a system of water-toluene. Then divinylbehzene was added into the organosol as cross-linking agent together with azo-iso-butyl nitrile as the initiator. An organic-inorganic composite microgel was obtained after reacting under supersonic stirring. This composite microgel showed very good amphiphilic properties. It could be transferred onto Si, CaF2 and quartz substrates from a pure water interface using the Langmuir-Blodgett (LB) technique. IR and UV-visible spectra of the composite microgel have shown the presence of some residual vinyl groups; this means that the microgel could be further polymerized. The stability of these polymer LB films can be improved by further polymerization. Transmission electron microscopy (TEM) was used to detect the quality of the monolayer fabricated with this composite microgel. Using TEM together with the small-angle X-ray scattering method we obtained a particle size in the range 19-27 angstrom. The structure of the ferric oxide in the composite microgel was identified to be alpha-Fe2O3 from X-ray photoelectron spectroscopy and electron diffraction data.