RESUMO
In this study, thin films of polymer poly(methyl methacrylate) were prepared using a drop casting method. Two newly synthesized aldehyde derivatives, 2-bromomalonaldehyde and 5,6-dihydroimidazo[2,1-b]thiazole-2-carbaldehyde, were used at different concentrations to dope the films. The prepared films were transparent and therefore studied for application in photonics. Optical characterization of the samples was carried out using different spectroscopy techniques. Absorption spectra for both samples were obtained using a UV-vis light spectrophotometer. Other significant optical parameters, such as refractive index, extinction coefficient, and band gap energies, were calculated from the absorption spectra. The effect of doping concentration on these parameters was studied. Emission spectra were obtained using a fluorescence spectrophotometer and the effect of doping was observed. Fourier transform infrared spectra of the doped films were obtained and compared with the pure compound to note changes in peak values and peak intensity. This present work studied the effect of doping on optical properties and examined the application of the samples for photonics.
Assuntos
Aldeídos , Óptica e Fotônica , Luz , Fótons , EspectrofotometriaRESUMO
Fluorescence quenching and preferential solvation of a coumarin derivative, namely 3-[2-oxo-2-(2-oxo-2H-chromen-3-yl)-ethylidene]-1,3-dihydro-indol-2-one (3OCE), with aniline used as a quencher in solvent mixtures of acetonitrile (AN) and 1,4-dioxane (DX) was carried out at steady state. Suppan's theory of dielectric enrichment was used to understand the nonideality and dielectric enrichment in AN-DX solvent mixtures. The effect of viscosity and dielectric constant variation at room temperature were analyzed. Quenching was characterized using Stern-Volmer plots with an upward curvature. It was found that 3OCE underwent combined static and dynamic quenching that was evident from the quenching rate parameters.