RESUMEN
A binary system composed of the liquid crystalline poly(propyleneimine) dendrimer and nematic p-n-pentyloxy-p'-cyanobyphenyl has been studied by thermomicroscopy, scanning calorimetry, and inverse gas chromatography. In this system, there is the columnar phase being stable within broad ranges of temperature and component ratio. Dependences of the retention volumes of various solutes, namely, hydrocarbons, alcohols, and amines, on composition of the sorbents are revealed to exhibit the maximum. Thermodynamic functions of sorption of n-alkanes and n-alcohols on the binary sorbents composed of the said liquid crystals have been calculated specifically. Thermodynamic solute-sorbent compatibility characterized by the activity coefficients of the solutes is dependent on the sorbent composition; namely, it is controlled by counterbalancing of the enthalpy or entropy factors. The nonadditive mode of the solute-sorbent interaction is explained by arising of the microdomain nematic structure enclosed in the columnar structure of the dendrimer.
RESUMEN
Aggregation behavior of unsubstituted copper porphyrazine (CuPaz) on the water surface was studied by analysis of compression curves, Brewster angle microscopy (BAM), and optical spectroscopy. The structure and stability of the CuPaz aqua aggregates in the floating layers are determined by hydration degree that depends on initial surface concentration and surface pressure. Langmuir-Schaefer (LS) films of CuPaz were prepared by deposition of the variously structured floating layers and studied by X-ray scattering technique and optical spectroscopy. Stable and labile structures were detected and compared with the floating CuPaz aqua aggregates. Conditions of formation of the stable four-stacked nanoaggregates in LS films were determined. A model comprising both nucleation of CuPaz on the water surface and structural transformations in the solid films is proposed.