engleski

Effect of Subphase Composition on the Molecular Organization in Complex Monolayers of Pyrene-3-sulfonate and Dioctadecyldimethylammonium Bromide at the Air/Water Interface

Organization of complex monolayers of pyrene-3-sulphonate (NaPyS) and dioctadecyldimethylammonium bromide (DOMA) at the air/water interface has been studied by surface pressure and surface potential measurements, by fluorescence spectroscopy and by reflection spectroscopy under normal and oblique incidence of light. Complex monolayers were formed using cospreading technique e.g. by spreading of mixed solutions of anchor lipid (DOMA) and NaPyS in different molar ratio. The effect of subphase composition on the monolayer organization and processes at the interface have been studied too. Fluorescence spectroscopic measurements showed the formation of excimers in mixed monolayers spread on water subphase and change of excimer to monomer emission in monolayers spread on different negatively charged electrolytes. The influence of polysaccharide xantan present in solution on association of pyrene molecules at the interface was investigated in more detail. It was also found that in complex NaPyS/DOMA monolayers pyrene molecules are located under the head groups of lipid monolayer.Reflection measurements gave additional informations on the molecular arrangements at the interface and indicated that transition moments of pyrene chromophores are in the layer plane with the angle of transition dipole with the surface normal less than 90o.

Pyrene-3-sulfonate ; dioctadecyldimethylammonium bromide ; air/water interface

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