FORMATION OF PLURONIC-CYCLODEXTRIN INCLUS ION-TYPE COMPLEXES IN A MONOLAYER AT THE WATER-GAS INTERFACE

The regularities of the formation of supramolecular complexes of hepta kis- (2,6-di-O-methyl)-beta-ceclodextrin with two amphiphilic pluronic s characterized by different molecular masses in a monolayer at the wa ter - gas interlace were studied by the Langmuir technique. Both pluro nics formed monolayers that interacted with cyclodextrin. The stoichio metry of the formed complexes al the water surface and in the solution was the same: one cyclodextrin molecule per two monomeric propylene o xide units. Upon the complex formation, pluronic undergoes the transit ion from the random coil to the rodlike conformation. The effect of th e surface pressure on the formation of the supramolecular complexes wa s studied for pluronic with lower molecular mass. An increase in the s urface pressure changed the position of the supramolecular complex at the water - gas interface. The complex in a liquid-expanded state was located in the plane of the interface, whereas in a transition state, it was set at an angle to this plane. Further increase in the surface pressure (over 10 mN/m) inhibited the complex formation.