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Olexander Ivankiv, Institute of Condensed Matter Physics, Ukraine Yurii Blazhyyevskyi, Institute of Condensed Matter Physics, Ukraine Taras Bryk, Institute of Condensed Matter Physics, Ukraine. Maksym Druchok, Institute of Condensed Matter Physics, Ukraine Ivan Klevets, Institute of Condensed Matter Physics, Ukraine Bohdan Kotur, Ivan Franko National University of Lviv, Ukraine Ivan Kravtsiv, Institute of Condensed Matter Physics, Ukraine Roman Melnyk, Institute of Condensed Matter Physics, Ukraine, Mykhajv City Council. Mykola Patsahan, Institute for Condensed Matter Physics, Ukraine Taras Patsahan, Institute for Condensed Matter Physics, Ukraine Petro Yakibchuk, Ivan Franko National University of Lviv, Ukraine.

Jaroslav ILNYTSKYI, Institute of Condensed Matter Physics, NAS of Ukraine A possible mechanism of formation of anisotropic textures in DNA films. 1. Shapes of Macromolecules in Porous Environments: A Theoretical Renormalization Group Approach Blavatska V., Institute of Condensed Matter Physics, Lviv, Ukraine. Kleshchonok A., National Taras Shevchenko University of Kyiv, Ukraine 5.Synthesis and characterization of H-shaped liquid crystals.

6. Maier-Saupe Nematic Fluid: Integral Equation and Field Theory Approaches Kravtsiv I., Institute for Condensed Matter Physics, Lviv, Ukraine.

Emergent Phenomena and Functional Materials

Invited Lectures

Analysis of the magnitude of the diffusion coefficients reveals that the LC ordering around the microparticles is disrupted in the bulk interfacial environment, leading to a small resistance of the microparticles at the aqueous-nematic interface. A systematic analysis of the relationship between the dielectric anisotropy (∆ε) value and the blue phase liquid crystal (BPLC) temperature range shows that the BP temperature range increases as ∆ε decreases. In addition, we also find that as the chiral concentration of the blue phase increases, the BP temperature range decreases.

A wide range of pore sizes, band widths, and fractions of components in a mixture are examined. In the uniform electric field, the dynamics is induced through two main mechanisms, the dielectric reorientation of the conductor (the reversal effect [1]) and through electrophoresis [2]. Simple procedures for monitoring aggregate formation can be proposed based on changes in characteristics measured with time.

A possible generalization of the proposed approach to dispersions of other types of anisotropic nanoparticles in LC media is discussed. Therefore, describing the response dynamics of liquid crystal systems to excitations is of considerable interest and importance. The fault lines of the blue phases are found to provide regular three-dimensional arrays of particle trapping sites.

We construct a theoretical model of the dielectric properties of a ferroelectric LC nanosuspension (FLCNS) using the generalized Maxwell-Garnett picture. We demonstrate for the first time that the electrical prehistory of the cells gives the Frederiks characteristics significant sensitivity to polarity. This reduces or increases the Frederiks transition threshold by 0.8 V depending on the polarity of the applied voltage, giving a net Frederiks threshold asymmetry of 1.6 V for the 8 µm thick cells filled with TL205 liquid crystal.

We investigated elasticity-mediated alignment, self-assembly and optical trapping of well-dispersed anisotropic gold colloids in liquid crystals as a function of particle shape and size. In fact, reverse phase liquid chromatography is now one of the most important separation techniques. In the present lecture, a version of density functional theory based on a model of tangentially connected spheres of chain molecules is presented.

After a short description of the model and the theoretical approach, three applications of the theory are presented.

Figure 1: Deformation field h(x, y) around a capillary “ar- “ar-row” at the air-water interface (experimental)
Figure 1: Deformation field h(x, y) around a capillary “ar- “ar-row” at the air-water interface (experimental)

Contributed Talks

These results are discussed in the context of coupling the colloidal particle dynamics to the dynamics of the nematic host. Theory of elastic interaction between colloidal particles in the nematic cell in the presence of an electric or magnetic field. The Green's function method developed in [1] is used to describe elastic interactions between axially symmetric colloidal particles in the nematic cell in the presence of an external electric or magnetic field.

The role of dipole-dipole correlations in biaxial ordering in bent-core liquid crystals Grzegorz Pająka,b and Mikhail Osipovb. The existing molecular theory of bent-core nematics has been developed mainly in the mean-field approximation. Thus, dipolar interactions in the nonpolar phase manifest through dipole-dipole correlations, which must be taken into account using a more advanced approach.

In contrast, the theory of flexoelectricity can be developed in the mean-field approximation because it is determined by a polar correction to the orientation distribution function that is proportional to the director's gradients. In addition, the flexoelectric coefficients have been computed numerically as a function of temperature in the mean-field approach, taking into account all dipolar contributions. In this work, the formation of anisotropic textures in dry films of DNA with chlorides of alkali metals is studied.

The obtained DNA films with NaCl, KCl and RbCl salts are characterized by dendritic textures, while LiCl and CsCl do not have them. In the case of NaCl, KCl and RbCl, the analysis shows that the phosphate groups of the double helix are neutral before the DNA coil is compressed between the film and substrate surface. In the case of an excess of LiCl and CsCl salts, complete neutralization of the phosphate groups of DNA occurs when the size of the coil is approximately equal to the thickness of the film.

The presentation will show how new liquid crystalline soft materials made of modified nanoparticles can be synthesized using various mesogenic molecules. This memory effect is achieved in the homeotropically aligned layers of the colloids based on nematic LCs with ∆ε < 0 and concentration of CNTs close to and above the critical value typical of percolation transition in these systems [1, 2].

Figure 2: Model of hybrid liquid crystal nanomaterial and structures of various mesogenic ligands used for surface modification.
Figure 2: Model of hybrid liquid crystal nanomaterial and structures of various mesogenic ligands used for surface modification.

Tutorial Lectures

We have shown that the formation of different structures can occur in liquid crystals for realistic values ​​of the temperature and the concentration of macroparticles. Due to a sufficiently large surface, such particles prescribe boundary conditions for the orientation of LC molecules depending on the adhesion to that surface, leading to a local deformation of the director's elastic field. In the former case, the surface itself prescribes the director orientation and acts as a source for the director field shift.

In the latter case, each inclusion acts as a director orientation perturbation because the boundary conditions on the surface do not correspond to the actual director distribution. First, we describe the influence of a separate macrokey on the deformation of the elastic field of the director and the scalar order parameter depending on the geometric configuration and dimensions and the boundary conditions on the surface of the separate macrokey. Under tangential boundary conditions on the inclusion surface, the router distribution takes on a spindle shape.

If the area of ​​a disturbance is large enough due to the overlapping of the deformation zones of the driving field for two or more macroinclusions, the effective interaction between them appears. We have described methods for determining the interaction energy through the elastic field of a conductor in the case of strong or weak anchoring of LC molecules on the surface of a particular inclusion. The effectiveness of such an interaction will be determined, first of all, by the geometrical parameters of an inclusion, the adhesive force of LC molecules on the surface of such an inclusion and the elastic properties of the medium.

In the general case, the value and character of the interaction is determined by the value and character of a violation of the director distribution symmetry. We have shown how a violation of the director distribution symmetry at short-range distances defines the interaction at long-range distances. We studied the conditions for the appearance and mutual transformation of the possible periodic structures.

He founded the pathological-anatomical museum at the University of Lviv and enriched the physiological and anatomical collections of the university. Planer's scientific discovery included the study of the occurrence of pigment granules in the blood, particularly indicating their connection with the course of intermittent fever.

Posters

The alignment characteristics were found to be strongly dependent on the LC material for the same chalcogenide glass. The resulting anisotropic angular distribution of the adsorbed molecules results in a light-induced easy LC orientation axis. In the initial state, the orientation of the nematic director is uniform across the cross-section of the cell.

The latter depends on the temperature of the sample, the coupling energy between a colloidal particle and a nematic host and the particle concentration. An odd-even effect of the central polymethylene spacer on the phase transition temperatures and enthalpies has been observed. Application of the electric field caused reorientation of the LC and change of the phase retardation modulation in the cell.

It allowed effective control of the diffraction efficiency of the grating, η, which reached maximum value ≈ 30%. In the case of one-dimensional constrained beam, different light intensity distributions have been used for calculations. The amplitude of the periodic director deviations increases while the ratio of cell thickness to anchorage energy period decreases.

At higher concentrations of azoxy nematic, λmax decreased regardless of the temperature behavior of the system. The influence of the surface on smectic liquid crystal configuration in bulk has been a subject of intense investigation for many years. The coupling term in the free energy must then be [(∂i∂j +q2ninj)δρ]2, which is independent of the sign of n.

Dynamics of the intramolecular structure were investigated using IR spectroscopy and optical methods. The influence of the anchor energy strength on the hysteresis of light induced Freedericksz transition in confined light beams. The influence of the nematic walls anchoring energy strength on the hysteresis of light-induced Freedericksz transition in light beam with finite diameter was considered.

The possibility of using such a system as a light waveguide in integral optical applications was investigated.

Contents

Зображення

Figure 1: Deformation field h(x, y) around a capillary “ar- “ar-row” at the air-water interface (experimental)
Figure 2: Model of hybrid liquid crystal nanomaterial and structures of various mesogenic ligands used for surface modification.

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