Self-aggregation and solubilizing properties of the supramolecular system based on azobenzenesulfonate calix[4]arene and CTAB

Abstract

The intermolecular interaction of azobenzenesulfonate calix[4]arene with cationic surfactant CTAB was studied by a complex of physicochemical methods. The influence of calix[4]arene:CTAB ratio on the form of the aggregates in their mixed composition in the aqueous medium was determined. Single-layer vesicles are formed in the equimolar azobenzenesulfonate calix[4]arene-CTAB mixture. A threefold increase in the proportion of CTAB leads to the enlargement of vesicles, namely, an increase in numbers of bilayers. Spectrophotometry was used to select the conditions for binding of the hydrophobic spectral probe Sudan I by this mixed composition. The fluorescence spectroscopy establishes dependence between the amount of encapsulated Rhodamine B and the size of the vesicle. Thus, the azobenzenesulfonate calix[4]arene–CTAB system is capable for binding of both hydrophobic and hydrophilic substrates depending on the components ratio.