On phase transitions in the water-ethylene glycol system at subzero temperatures under non-isothermal conditions.
The dynamic phase diagrams of the water-ethylene glycol (EG) system have been plotted at the warming rate of 0.4 degrees C/min(-1) after cooling of samples down to -196 degrees C by quenching in liquid nitrogen or slow cooling at the rate of approximately 0.15 degrees C/min(-1). The melting of two stable eutectics at the temperatures of -42.7 degrees C and -48.7 degrees C and the metastable eutectic at -63 degrees C was observed. Hydrates 1:1 crystallized separately from ice during warming both after quenching and after slow cooling. Glass devitrification and EG:3H(2)O hydrate melting took place during warming of the samples after quenching but these thermal features were absent after slow cooling in the EG concentration range of 42.0 - 63.5 weight percent. The notions about two-stage mechanism of ice nucleation in EG aqueous solutions might be critically revised
Zinchenko
A V
AV
Institute for Problems of Cryobiology and Cryomedicine of the National Academy of Sciences of Ukraine, Kharkov, 61015, 23, Pereyaslavskaya str., Kharkov, Ukraine. cryo@online.kharkov.ua
Zinchenko
V D
VD
D002151:Calorimetry; D003080:Cold Temperature; D003460:Crystallization; D019855:Ethylene Glycol / Q000737:chemistry*; D007053:Ice; D014867:Water / Q000737:chemistry*
D007053:Ice; D014867:Water; D019855:Ethylene Glycol