A novel supramolecular system based
on calix[4]resorcinarene sulfonatoalkylated
at the lower rim and piperidine-methylated at the upper rim and the
cationic surfactant hexadecyl-1-azonia-4-azobicyclo[2.2.2]octane bromide
was investigated by methods of NMR, tensiometry, conductometry, potentiometry,
dynamic light scattering, X-ray powder diffraction, and spectral probe
techniques. Both types of molecules were found to self-associate in
aqueous solution, with aggregates of different morphology formed.
Importantly, a supramolecular amphiphilic binary system with controlled
structure and binding behavior could be fabricated. At high surfactant
concentration, the formation of its own aggregates takes place. In
the systems with the excess of cyclophane the supramolecular amphiphiles
are formed, which, in turn, self-assemble in particles with a large
hydrophobic core. Thereby the structure of supramolecular species
is determined by relative fractions of components and, hence, could
be selectively controlled. The found properties can be used for the
design of nanocontainers with the controlled cavity size.
The aggregation in aqueous solutions of alkylated 1,4 diazabicyclo[2.2.2]octanes of various hydrophobicity and their adsorption at the water-air interface were studied by tensiometry, conductometry, potentiometry, viscosimetry, and ESR spectroscopy. The parameters of ad sorption, critical micelle concentrations, concentrations of free counterions (bromide ions), and degree of binding of the counterions with micelles were determined. The intensification of the micelle formation ability of the surfactants with an elongation of the alkyl fragment was shown. The effective radii of ensembles of the hexadecyl and octadecyl derivatives were deter mined by the dynamic light scattering method. A relationship between the concentration de pendences of the size of micelles and their shape was established.
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