Preparation of clay/pyronin B composites: Study of photophysical properties

The aim of this study was to investigate the aggregation produced from interactions between the Pyronin B (Py B) dye compound, in low concentrations, and bentonite clay particles. For this purpose, UV-Vis absorption, steady-state fluorescence and time resolved fluorescence spectra were taken in different conditions such as different pH, concentrations and waiting times. Beside all of these, fluorescence lifetimes of related to all samples were determined. In this study, interactions between PyB and clay minerals were studied in liquid solutions and thin films by using spectroscopic techniques. H-aggregate has been observed from these interactions and the photophysical properties of H-aggregate were investigated. The Clay/PyB composite structure has been studied by UV-Vis absorption, steady-state fluorescence, time-resolved fluorescence, XRD and FTIR techniques. Morphology of composite was studied with SEM technique. Interaction between clay and Py B was studied in different times and pH and the best pH for aggregation was found. Thin film of Clay/PyB composite was produced and characteristics of thin film were studied with above mentioned manners. Interactions between thin films and different solvents with different polarity so the intensity of aggregation peak changes were followed. The adsorption process of PyB by clay minerals was examined depending on contact time and initial asorbate concentration. An adsorption isotherm was good–fitted by the Freundlich model with a linear regression correlation value of 0.990. The adsorption of PyB by clay was in agreement with pseudo second–order kinetics.