A refractometric method, coupled with molecular dynamics study, attenuated total reflection Fourier transform infrared (ATR FT-IR), and Raman spectroscopy, was used to determine optical characteristics of concentration features of aqueous solutions of acetic acid. Measurements of the refractive index of aqueous solutions of acetic acid in the wide range of acetic acid concentrations (∼ 0 ÷ 1 mole fraction) in a solution at a room temperature were conducted. Maximum value of refractive index was detected at a concentration of ∼0.3 mole fraction. The deviation from the parabolic form of the dependence of the refractive index on the concentration occurs at a concentration of ∼0.8 mole fraction. As far as we know, this deviation has been observed for the first time. The maximum is attributed to the largest number of molecular interactions between water and acetic acid molecules, while the deviation is associated with the parallel orientation of acetic acid molecules. To identify the reconstructing of molecules in the system, FT-IR and Raman spectra of these solutions at a concentration of ∼0.3 and ∼0.8 mole fraction were recorded and compared with pure solutions. The data obtained by using ATR FT-IR and Raman spectroscopy support the idea that the refractometric method is sensitive to determine the structural states of aqueous solutions of acetic acid.

The effect of cluster formation in a fullerene mixture C_60/70 (D_5h-C₇₀ — 95 mass percent and I_h-C₆₀ — 5 mass percent) solution in toluene on the electronic properties and the infrared absorption spectra during long-term (60 days) storage under isotermic conditions is studied. The features of the structure of (C _60/70)_N clusters have been studied using high-resolution transmission electron microscopy and a fractal mechanism is proposed for the formation of large (~291.4 nm) stable clusters, which may contain up to ~19698 molecules of C₇₀ and ~1036 molecules of C₆₀. The precise values of the nonlinear optical susceptibility χ⁽³⁾ _xyyx (ω) of the C_60/70 solutions for different laser beam polarizations (in the range of ellipticities θ = 0.1 − 0.8) are determined. The physical mechanisms of the laser-induced optical activity of a C_60/70 solution in toluene are discussed.

The results of experiments on the self-aggregation of C60 fullerene molecules both inside a two-component solvent (xylene/tetrahydrofuran) and in the volume of an evaporating drop of C60 colloidal solution on a flat substrate surface are presented. The investigations of C60 solutions using dynamic light scattering, transmission electron microscopy and UV–Vis absorption spectroscopy methods revealed the possibility of synthesis of fractal nanoaggregates with a diameter of up to ~135 nm at low concentrations of C60 in the solutions. The final geometric dimensions of C60 nanoaggregates were determined by the initial concentration of fullerene in the solvent medium. Using the scanning electron microscopy method, we have shown that in an open dissipative system – in the volume of an evaporating droplet of the colloidal solution of fullerene C60 sessile on the surface of a flat glass substrate, large quasispherical nanoaggregates with an average diameter of ~380–800 nm are formed. The physical features and regularities that characterize the processes of self-aggregation of fullerene particles in the volume of a drying drop were determined.

The ways for a synthesis of nanoporous and close-packed types of fullerene C₆₀ aggregates in two-component organic solvents (toluene + tetrahydrofuran) were established as well as their structural and dimensional features - were studied by high-resolution transmission electron microscopy and atomic-force microscopy methods. The physical features and regularities that characterize the processes of self-organization of fullerene molecules in the initial molecular solution were determined. The method for producing nanoscale fullerene C₆₀ fractal coatings (thickness up to ∼1200 nm) on a flat dielectric glass surface was proposed.