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Information × Registration Number 0218U001232, 0113U002482 , R & D reports Title Electrical, magnetic, and nonlinear optical properties of the dispersion nanoparticles of different nature in oriented liquid crystals. popup.stage_title Head Nazarenko V.G., Registration Date 26-01-2018 Organization Institute of physics NASU popup.description2 The main goal of this project was the development of new materials based on liquid crystalline colloids, the study of their structure and physicochemical properties, the improvement of the properties of liquid crystal mesophases and the search for new effects with applied potential. The project studied the interaction between particles in a nematic or lyotropic matrix and their effect on the structure of a liquid crystal (LC). The appearance of new mesophases in liquid crystals, which initially had only a nematic phase, was investigated. It is shown that strong orientation interaction between components in a two-component LCD suspension of hard rods (Onzagger fluid) enables efficient control of the anisotropy of such dispersions and leads to their high sensitivity to external fields. The study of the temperature of the phase transition and the dielectric properties of LC 8CB, doped by conventional and selected by a special method of ferroelectric nanoparticles, was studied. It was shown that an increase in the average polarization of nanoparticles leads to an increase in the temperature of the phase transition of the colloid. Dielectric constants for ferroelectric RK colloids were obtained by measuring dielectric permittivity of samples in the presence of a weak field and by calculating them from measurements of the temperature of the phase transition. The effect of carbon nanotubes (CNT) on the orientation parameters of the LCD layer, on the thermal stability of the suspension layers orientation, on the electrode double layers and electrical conductivity was also investigated. The peculiarities of the structural organization of CNT in nematic LC in a wide range of concentrations (10-5- 3 wt%) were investigated. It is shown that the process of evolution of the structure of BNT with the growth of their content in RK can be divided into 4 stages: 1) the stage of separate tubes, their harnesses and small aggregates (<3 microns), 2) stage of growth of aggregates and their branching, 3) stage of a loose net and 4) stage of a dense grid. The theoretical model of temperature distribution in a cell filled with RK with golden nanoparticles under the influence of irradiation is developed, which allows to calculate the coefficient of optical nonlinearity in such a system and is well in agreement with experimental results. The dependence of the coefficient of optical nonlinearity of the system on a number of its parameters, such as the intensity of the pump beam and the concentration of gold nanoparticles, have been experimentally determined. The dependence of the optical nonlinearity is established and the possibility of controlling the nonlinearity value by means of an electric field is shown. A new method was proposed to streamline micro and nanoparticles and manipulate their chains at distances up to a centimeter range. This method consists in the use of topological defects in LC that are able to capture nanoparticles. And also in the possibility of manipulating disclinations using external factors, such as light, temperature, electric field, and others. The proposed method in the long run allows creation of the newest metamaterials that are capable of transforming and correspondingly changing their physical properties. The structure of new nanocomposites was thoroughly investigated, in which nanoparticles are directly synthesized in the matrix of a smectic ionic liquid crystal of metal alkanoates at T = 100-1800 C. Metal alkanoates exhibit a unique ability to exist in the form of an ionic liquid crystal at high temperature, and when cooled to room temperature to form solid, anisotropic glass, which retains the layered structure inherent in smectic A. Experimental studies were supported by theoretical studies of the interaction between the nematic matrix and nanoparticles. In the process of project implementation, the following research methods were used: electro-, magneto-optical, photorefractive, dielectric broadband spectroscopy, atomic-strength microscopy, infrared spectroscopy, low-temperature fluorescence, electron absorption and reflection spectroscopy, X-ray diffraction method. The results obtained in these studies will be used to develop practical recommendations for new, extra-sensitive electromagnetic and magnetic materials, and to build prototypes of devices for displaying and processing optical information. Over the period of the topic В/174 52 articles were published and more than 48 reports were presented at international scientific conferences, and 3 PhD theses were defended, and one was prepared in the near future. Product Description popup.authors Ільїн Андрій Григорович Бідна Тетяна Вікторівна Бугайова Людмила Миколаївна Бугайчук Світлана Анатоліївна Булуй Олександр Григорович Жулай Дмитро Сергійович Касянюк Денис Володимирович Клімушева Гертруда Василівна Кравчук Руслан Миколайович Креденцер Сергій Вікторович Курйоз Юрій Іванович Курочкін Олександр Вікторович Назаренко Василь Геннадійович Полтко Констянтин Юрійович Роде Герольд Григорович Терещенко Олександр Григорович Толочко Анатолій Степанович Томілко Сергій Валентинович Шеремет Ніна Василівна Ярощук Олег Васильович popup.nrat_date 2020-04-02 Close