Динамика кристаллизации твердого этанола

Физика низких температур. 2018. Т. 44. № 10. С. 1404–1411.

Ефимов В. Б., Изотов А. Н., Rybchenko O.

Experimental studies of the kinetics of phase transitions of C2H5OH ethyl alcohol samples from amorphous to crystalline phase demonstrated that their transition rate and energy characteristics strongly depend on the size and composition of the samples (rectified alcohol, absolute alcohol). Almost all bulk amorphous samples of rectified alcohol that were several millimeters in size crystallized into the monoclinic phase within few hours at a temperature of T ∼ 125 K, while in amorphous nanocluster samples consisting of clusters of the order of tens nanometers in size, a similar transition was observed at T ∼ 110 K. Characteristic transition times from one crystalline phase to another also differed greatly. Temperatures at which the transition from the plastic to the monoclinic phase occurred for both bulk and nanoclusters samples of absolute alcohol were lower (100–105 K), and crystallization of nanocluster samples occurred much more rapidly. The exponent moduli in time dependence of x ∼ t n in the JMAK model (crystallization of an amorphous substance) strongly depended on temperature, and for nanocrystallites were of the order of one or less. However, for massive samples, the exponent modulus n turned out to be closer to two for both rectified and absolute alcohol.

Keywords: ethanol, amorphous state, сrystallization, X-ray diffraction, этанол, рентгеновская дифракция, аморфное состояние, кристаллизация