Fourier Transform IR and Fluorescence Spectroscopy of Highly Ordered Functional Polymer Langmuir—Blodgett Films

Abstract

FT-IR spectroscopic measurements (polarized transmission and reflection absorption spectra (RAS) of N-octadecylacrylamide (ODA) LB films indicate that ODA molecules are oriented nearly perpendicular to the surface of the plate, moreover, they are arranged in the plane along the dipping direction (in-plane order). ODA LB films have a biaxial orientation. The emission spectroscopic study for the aromatic chromophore incorporated into the highly ordered N-alkylacrylamide polymer LB films is carried out. The emission spectra for the LB films were measured as a function of the deposited layer and the alkyl chain length of N-alkylacrylamide polymers. The excimer emission intensity increased with increasing number of deposited layers when the effective interlayer energy transfer to the excimer forming site is taking place. The efficiency of vertical energy transfer in the Y-type polymer LB films for naphthalene, pyrene, carbazole and fluorene chromophores was safely judged from the increase in the excimer emission intensity as a function of the deposited layers in the emission spectra. The limiting energy transfer distances for each chromophores are correlated with critical energy transfer distance of Förster type.