Факультет технічних систем і енергоефективних технологій (ТеСЕТ)
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Item Selective to lithium ions nanocomposite sorbents based on TiO2 containing manganese spinel(SHEI "Ukrainian State University of Chemical Technology", 2021) Chaban, M.O.; Rozhdestvenska, L.M.; Palchik, O.V.; Пономарьова, Людмила Миколаївна; Пономарёва, Людмила Николаевна; Ponomarova, Liudmyla Mykolaivna; Dzyazko, Y.S.A method for obtaining nanocomposite sorbents, which are selective towards Li+ ions, has been proposed. The samples were based on adsorptive-active anatase, the selective component being lithium-manganese spinel LiMn2O4. This component was synthesized preliminarily, its nanoparticles were added to the sol of insoluble titanium hydroxocomplexes, and the nanocomposite was precipitated from this suspension and calcined at 5000C. A number of sorbents with different molar ratio of Ti:Mn were prepared via this procedure; they were investigated by means of chemical analysis, X-ray diffraction analysis, optical microscopy, transmission electron microscopy and scanning electron microscopy. The size of nanocrystallites was 20–30 nm. An increase in the spinel amount caused a decrease in the sorbent grain size; however, they the sorbent grains were mechanically durable due to TiO2 which was a binder. Adsorption of Li+ from the solution containing an excess of Na+ ions was studied. The optimal amount of LiMn2O4 (13%) was determined. The sample was obtained in the form of rather large grains (0.3 mm) and the selectivity coefficient Li+/Na+ was about 500. The sorbent was regenerated by a 1 M HNO3 solution without manganese leakage. After 10 cycles of sorption-desorption, the concentrate was obtained. This concentrate can be used for Li2CO3 precipitation.Item Modification of ultrafiltration polymeric membranes with dispersed oxide nanoparticles(Ukrainian State University of Chemical Technology, 2020) Rozhdestvenska, L.M.; V’yunov, O.I.; Пономарьова, Людмила Миколаївна; Пономарёва, Людмила Николаевна; Ponomarova, Liudmyla Mykolaivna; Bilduykevich, A.V.; Plisko, T.V.; Zmievskii, Y.G.; Ivchenko, V.D.Organic-inorganic membranes containing the nanoparticles of hydrated zirconium dioxide and BaFe12O19 magnetic nanoparticles were prepared. The nanoparticles were inserted into polymer matrices. Ultrafiltration membranes were used as a polymer substrate. These materials consist of macroporous layer (non-woven polyester) and ultrathin active layer (polysulfone or polyacrylonitrile). Morphology of the membranes was investigated using scanning electron microscopy. It was established that inorganic nanoparticles form aggregates, a size of which is up to 20 nm in active layer and up to 2 m in macroporous fibrous support. Larger aggregates are formed in the absence of a magnetic constituent (up to 5 m). Fractal analysis showed the diffusion-limited aggregation model of particle formation. The inorganic particles form a «secondary active layer» inside the polymer pores: this layer determines water flux and rejection ability of the membrane. A thinner «secondary active layer» is formed in the polymer matrix containing smaller pores. The prepared membranes were tested for filtration of sugar beet juice. The modification was shown to improve the ability of the membranes to reject proteins. Due to smaller particle size, the membrane containing BaFe12O19 shows the liquid flux of 4.310–7–5.710–7 m3m–2s –1 at 2 bar and the rejection towards vegetable protein of 55–87%. Regarding the membranes that do not include magnetic nanoparticles, these values are 3.810–7–5.510–7 m3m–2s –1 and 38–77%, respectively.