растворимость

Phase equilibria and solubility have been studied by the visual polythermal method in mixtures of components along a series of sections of the composition triangle within the temperature range of 10–60°C in the ternary systems lithium carbonate – water – diisopropylamine (triethylamine). For each system, the temperatures of formation of the critical node of the monotectic state have been determined: in the system with triethylamine, it is 14.0°C, and with diisopropylamine, it is 22.4°C.

The solubility of potassium iodide in the mixed solvent water – tretbutyl alcohol (tret-C₄H₉OH) was studied by means of the sections method at 25°C under atmospheric pressure. The phase diagram of the KI – H₂O – tret-C₄H₉OH system has been plotted and discussed. The system is classified as that with salting-out.

Phase equilibria and solubility have been studied by the visual polythermal method in mixtures of components in nine sections of the composition triangle in the range of 10–70° C in the ternary system ammonium sulfate – water – polyethyleneglycol-1500 (PEG-1500). The dependence of the compositions of solutions corresponding to the critical solubility points of the stratifi cation region on temperature has been found using the liquid phase volume ratio method.

A critical review of the literature on the methods of concentration and extraction of biobutyric acid from fermentation solutions has been carried out. The best results of these processes are achieved by combining extraction with salting. It is proposed to use polyethylene glycols with diff erent molecular weights as non-fl ammable and environmentally friendly extractants.

A technique of laboratory  synthesis  of potassium formate has  been developed. Phase equlibria in mixtures  of the components  of the binary  system potassium formate - water in the range from -70 to +170°C were investigated by  the visual-polythermal method. For the first time the phase diagram of the specified system has  been con­ structed and the coordinates  of an eutectic  point has  been estab­ lished. The formation of a crystalline hydrate КНСООИ.бНгО incon­ gruous  melting at -9.2°C was  found in this  system.

Investigated the conditions of formation and solubilization ion associate synthetic food dye «brilliant blue» (Е133) ions with cetylpyridinium chloride (TSPKH). The composition of the associate, the solubility in water and micelles TSPKH. The importance of such interactions in the photometric, potentiometric and other methods of determination of synthetic food dyes.

Dipropylamine is one of the promising antisolvents for extractive salt crystallization, but its solubility in water and phase equilibria in its aqueous solutions over a wide temperature range has not been studied in detail until now. The review of the literature shows that the water-dipropylamine system is classified as a self-separating system with a lower critical solution temperature (LCST). We used the visual-polythermal method in a –25–90°C range to study phase equilibria in the binary system water-dipropylamine and to plot the phase diagram of the system.

A brief review of computational methods for the liquid-liquid equilibrium has been carried out, and their capabilities and limitations have been shown. Complications of such computational models for the liquid–liquid–solid equilibrium lead to a decreased accuracy of calculations. In this case, it is advisable for researchers to make use of the approximation of experimental data on the liquid – liquid and liquid – liquid – solid equilibria.

Phase equilibria in the ternary system sodium nitrate – water – dipropylamine where the constituent binary liquid system is characterized by a trend to form a lower critical solution temperature (LCST) were studied using the visual-polythermal method in the range ?10.0–90.0° C. It was found that the introduction of sodium nitrate into the water – dipropylamine system led to a significant decrease in the mutual solubility of the components.

Phase equilibria in the water–butyric acid binary system in the range of ?10?0° C and in the sodium chloride–water–butyric acid ternary system in the range of 10.0?60.0° C were studied using the visual polythermal method. The phase diagram of the water–butyric acid binary system at ?9.5° C is characterized by eutectic equilibrium, the solid phases of which being ice and butyric acid crystals. The metastable delamination range was found on the ice crystallization field, bounded by a binodal curve with an upper critical solution temperature of ?3.7° C.