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Information × Registration Number 0225U002480, (0123U102995) , R & D reports Title Nanostructured optical materials based on suspensions of molecular aggregates in liquid crystals popup.stage_title Відпрацювання формування J-агрегатів у рідкокристалічних матрицях різного складу. Визначення на оптичних характеристик J-агрегатів в залежності від параметрів РК матриць. Визначення фотостабільності різних рідкокристалічних дисперсій J-агрегатів. Вимірювання оптичних та електрофізичних характеристик РК в залежності від типів J-агрегатів. Створення модельних зразків оптичних матеріалів на основі J-агрегатів. Head Samoilov Oleksandr M., Кандидат фізико-математичних наук Registration Date 14-03-2025 Organization Institute for Scintillation Materials of National Academy of Science of Ukraine popup.description1 Creation of new optical materials based on luminescent molecular aggregates (J-aggregates), dispersed in liquid-crystal matrices for application in photonics, optoelectronics and photovoltaics. At the same time, the main attention will be given to the possibility of influence to the luminescent characteristics of J-aggregates of cyanine and other colorants when forming in liquid crystal matrices due to supramolecular ordering in liquid crystals (LK), that can be changed under the influence of an electric field. popup.description2 The process of molecular aggregate formation (H- and J-type) of organic cyanine dyes in liquid crystal (LC) matrices was investigated. Suspensions of cyanine dyes were obtained: TDBC, PIC, an amphiphilic analog of PIC (amphi PIC), a variation of PIC with a hydrocarbon tail of C9 length, and TCC in a nematic LC matrix 5CB and a cholesteric LC matrix M5. Introducing dyes into the LC matrix was optimized using two methods: (1) the direct addition of dry dye powder into the liquid crystal and (2) the preparation of a dye solution in chloroform, water, or DMF followed by solvent evaporation. The first method was shown to be preferable, as the use of solutions led to residual solvent in the system, introducing significant experimental inaccuracies. The aggregation characteristics of cyanine dyes were studied, and the conditions for J-aggregate formation were established. Compared to similar processes in aqueous solutions, an increase in luminescence lifetime and a slowdown in the aggregation process were observed. The Fredericks transition was investigated for systems based on 5CB, demonstrating that the presence of molecular aggregates of cyanine dyes in the LC system makes the Fredericks transition more "abrupt." A significant enhancement in the photostability of J-aggregate dispersions was observed for the TDBC dye in both nematic liquid crystal 5CB and cholesteric M5. The concentration range for J-aggregate formation in the studied LC matrices was determined. It was noted that, depending on the concentration of TDBC dye, aggregates of different types may form. At the same time, it was shown that, in contrast to J-aggregates, H-aggregates are sensitive to phase state changes in the LC matrix. A model was proposed to explain the observed aggregation behavior of the TDBC cyanine dye in the LC matrix. Product Description popup.authors Ropakova Iryna Yu. Samoilov Oleksandr M. popup.nrat_date 2025-03-14 Close