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S. V. Pasechnik¹, G. I. Maksimochkin¹, D. V. Shmeliova¹, A. O. Zhirkov², S. Kralj³, O. A. Semina¹

Author affiliations
¹Problem Laboratory of Molecular Acoustics, Moscow Technological University,
20 Sromynka St., Moscow, 107996, Russia
E-mail: s-p-a-s-m@mail.ru
²Laboratory of ultra-high-speed optoelectronics and information processing, Lebedev Physical Institute,
53 Leninsky Pr., Moscow, 119991, Russia
³Faculty of Natural Sciences and Mathematics, University of Maribor,
160 Koroska, Maribor 2000, Slovenia

Abstract
Autocorrelation function g₂(τ) and intensity (I) of the depolarized scattered light were obtained at the study of a dynamic light scattering from the composite liquid crystal (LC) material, consisting of porous polyethylenterephthalate (PET) film filled with oсtylcyanobiphenyl (8CB). The simultaneous analysis of these parameters made possible to extract the temperatures T_IN and T_NA of the isotropic liquid – nematic (N–I) and nematic – smectic A (N-SmA) phase transitions in LC samples confined into cylindrical pores of diameters in the range of 0.02 … 2 μm. The dependences of T_IN and T_NA on the pore diameter were obtained and compared with the theoretical predictions. It was shown that simultaneous investigations of dynamic and static light scattering can be considered as a perspective approach for a study of phase transitions in LCs at strong confinement, which is typical for composite LC materials.

Keywords: liquid crystals, porous films, phase transitions, dynamic light scattering, static light scattering