Peculiarities of Concentration Quenching of Fluorescence of Dye Molecules Adsorbed on a Silicon Dioxide Heterogeneous Surface

摘要

Peculiarities of the nonradiative transfer of the electronic excitation energy between organic dve molecules adsorbed on a fine-pore silicate glass are considered in connection with a decrease in the fluores cence quantum yield with increasing concentration. It is assumed that physically adsorbed molecules can have several equilibrium position states on the adsorbent surface corresponding to their different orientations. Con-ditions of the statistical equilibrium of the orientation states are analyzed. The distribution of dye molecules in a silicate matrix is assumed to be a fractal one. Based on experimental data on the concentration quenching of fluorescence obtained for six dyes, the fractal dimensionality and fluorescence quantum yields are determined for these molecules in each orientation state.