Lattice dynamics

Specifics of n-Alkanes Polymorphism during Temperature Phase Transitions

S. A. Gur'eva^a, V. A. Marikhin^a, E. N. Vlasova<sup>b

a</sup> Ioffe Institute, St. Petersburg, Russia
^b Institute of Macromolecular Compounds, Russian Academy of Sciences, St. Petersburg, Russia

Abstract: The differences in the kinetics of the polymorphic transformation of crystallographic phases of n-alkanes of different parities: tricosane С$_{23}$Н$_{48}$ and tetracosane С$_{24}$Н$_{50}$ were studied using Fourier transform infrared spectroscopy. It has been established that a first-order structural phase transition occurs with a change in the symmetry type of the initial orthorhombic or triclinic subcells to hexagonal ones through the formation of a number of intermediate rotator phases $(R_I, R_{II}, R_V)$ depending on the symmetry of the molecules (cis or trans).

Keywords: n-alkanes, lamellae, phase transitions, rotator phases, IR spectroscopy.

Received: 06.10.2023
Revised: 06.10.2023
Accepted: 01.11.2023

DOI: 10.61011/FTT.2023.12.56776.246

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