ИСТИНА

The water-monoethanolamine (MEA) and water-3-aminopropanol (3AP) systems were studied. Research methods: differential scanning calorimetry, heat capacity measurement, IR spectroscopy and quantum chemical calculations, dynamic light scattering. Main results: phase diagrams of the studied systems were built; the found low-temperature liquid phases were explained by the presence of mixed spatial networks of hydrogen bonds in the systems as a consequence of a rather strong amino alcohol-water interaction leading to the formation of MEAn·H2Om and 3APn·H2Om associates in the liquid phase and compounds in the solid phase. When studying the temperature dependence of the heat capacity of pure MEA, a solid-phase transition was registered in the region of 200-220K. The studied systems are widely used in cryobiology for long-term storage of living cells and organs due to the presence of low-temperature liquid phases, the difficulty of crystallization, and the ease of vitrification at very low temperatures, which is explained by the presence of spatial mixed networks of H-bonds in these systems.