INVESTIGATION OF THE STRUCTURE OF THE ADSORPTION LAYER OF NONIONIC SURFACTANT TX-100 AND OF THE PYROGENIC DISPERSIVE SILICA SURFACE GENESISUSING THE PHOTOTRANSFER REACTION

The influence of a silica (aerosil) surface on the reaction kinetics o f a photoinduced electron transfer and quenching of fluoresence of pyr ene (Py) in the presence of N,N-dimethylaniline (DMA) when adsorbed fr om hexane has been studied. A photoreaction between Py and DMA is obse rved; over a wide range the quenching of the Py fluorescence obeys a S tem-Volmer equation mainly. When Py and DMA are solubilized in aqueous micelles of TX-100 and then adsorbed on an aerosil surface, the influ ence of the surface on the photoreaction kinetics is negligible. Remov al of water from the above system leads to the suppression of the phot oreaction. The apparently abnormally long lifetime of Py may be explai ned by a rearrangement of an adsorption layer, micelle degradation, an d encapsulation of the fluorophore.