STRUCTURE OF CDS NANOPARTICLES CONTAINING CADMIUM ARACHIDATE LB FILMS

Y-type cadmium arachidate LB films were exposed to H2S gas for differe nt durations. UV-VIS absorption spectra reveal an absorption edge at 4 55-460 nm in a 30 min H2S exposed him which does not change appreciabl y on further exposure, The blue shifted absorption edge is attributed to the formation of 30 Angstrom CdS nanoparticles. The H2S exposed fil ms exhibit two types of layered structures, that is, the original bila yer spacing of 55.2 Angstrom as well as an additional bilayer spacing of 44 Angstrom. The XRD peak intensities corresponding to the new bila yer spacing (44 Angstrom) increase up to 6 h of H2S exposure accompani ed by an increase in bandgap absorption. These results suggest that Cd S nanoparticles are formed within domains having tilted arachidate mol ecules distributed throughout the film without completely destroying t he original layered structure of the LB film. Copyright (C) 1996 Elsev ier Science Ltd