Luminescence of oxadiazole derivatives in poly(emthylmethacrylate) langmuir-blodgett matrix

摘要

Emission and excitation spectra of fluorescense have been studied for three oxadiazole derivative (OXD) incorporated in Langmuir-Blodgett (LB) films mixed with poly(methylmetacrylate) (PMMA). State diagrams and free mixing energies of components in monolayers have ben investigated. As the OXD concentration increases, the monolayer structurization process becomes subdivided into two stages. At the first one, limited mixing of components in monolayers occurs while at the second, the dopant is released as a separate phase of the monolayer. In LB films, molecular aggregates have been found which are not observed in other phase OXD states (toluenic solutions, spin-coating and polycrystalline films). The molecular arrangement in those aggregates is defined by the interaction of chromophoric fragments and ending alkyl substituents both with each other and with spreaded macronolecular PMMA chains being in 2D geometry specific for monolayers.