Orientational fluctuations and phase transitions in 8CB confined by cylindrical pores of the PET film

Dynamic and Static Light Scattering at Phase Transitions in Liquid Crystal Confined Into Porous Polymer Film

“…The details of calculations can be found in [9]. The comparison between the theoretical and experimental dependencies ΔT NA (R) and ΔT IN (R), obtained by two methods, are presented in Fig.…”

“…The theoretical analysis of the obtained results can be made in the framework of the generalized Landau -de Gennes -Ginzburg type phenomenological approach presented in [9]. In particular, the shifts ΔT IN = T IN (R) -T IN and ΔT NA = T NA (R) -T NA of the phase transitions temperatures T IN (R) and T NA (R), imposed by confinement in 8CB-PET system, respectively to the values T IN and T NA for bulk samples can be expressed as:…”

“…It makes the problem of calculation of normal modes of the director fluctuations inside pores more difficult in the comparison with the case of homogeneous orientation, realized in plane layers of LC [1]. Nevertheless, analysis of correlation function in DLS measurements makes possible to get information about temperatures of phase transitions in LC confined to pores of polymer film [9]. One has to take into account that the noise component in the autocorrelation scattering function increases with decreasing of the pore size.…”

Photon Correlation Spectroscopy for Investigation of Viscous-Elastic Properties of Shock-Free Ferroelectric Liquid Crystal

“…Among number of experimental methods used for measurement of elastic and viscous properties of liquid crystals (LC), the photon correlation spectroscopy showed essential advantages as a universal field free tool for studying liquid crystal systems of different types, such as plane layers of liquid crystals [1,2], porous glasses [3] and polymer films filled with LC [4,5]. This technique is based on study of frequency spectrum of dynamic light scattering (DLS) induced by thermal fluctuations of director which is described in terms of the autocorrelation function of the scattered intensity [6].…”

Octylcyanobiphenyl Liquid Crystal Confined to Anisotropic Porous PET Films at Homeotropic Anchoring: Optical Textures and Internal Ordering

“…Several director configurations were predicted for both nematic and SmA phases within cylindrical cavities [8]. Previously, internal ordering and phase behavior of 8CB (characterized by both nematic and SmA phases) within submicrometer and micrometer cylindrical cavities were studied by the nuclear magnetic resonance [9], calorimetry [10,11], X-ray [12] and dynamic light scattering [13].…”