Видання зареєстровані авторами шляхом самоархівування
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Item Atomistic modelling of frictional anisotropy of palladium nanoparticles on graphene(Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 2021) Хоменко, Олексій Віталійович; Хоменко, Алексей Витальевич; Khomenko, Oleksii Vitaliiovych; Захаров, Мирослав Владиславович; Захаров, Мирослав Владиславович; Zakharov, Myroslav VladyslavovychThis article is a continuation of our previous studies of the frictional anisotropy of metal nanoparticles on the surface of a graphene substrate for other temperature conditions. The friction force acting on palladium nanoparticles on a graphene sheet in various lateral directions is investigated using classical molecular dynamics modelling. Anisotropy is studied at high sliding speeds of nanoparticles consisting of 10000 atoms on the surface of graphene. The effect of incommensurability and short-range order of the contact surfaces of nanoparticles, as well as the graphene deformation lead to the absence of an expressed angular dependence of the friction force.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.Item Nanotechnology in medicine(Sumy State University, 2017) Svikolnik, A.In today's world often facing humanity faces global problems. Significant help in solving various problems can provide nanotechnology. In some biology and other sciences often use them is crucial.Item MD simulation of AlCoCuFeNi high-entropy alloy nanoparticle(Sumy State University, 2016) Kushnerov, O.I.High entropy alloys (HEA) are metallic compounds containing from 5 to 13 metallic elements in equiatomic ratios. In HEAs, because of the high mixing entropy, formation of brittle intermetallic phases is usually avoided and simple solid solutions are rather stabilized (BCC and/or FCC). This study used molecular dynamics (MD) package LAMMPS to simulate the AlCoCuFeNi nanoparticle (NP) crystallization.Item Secondary Crack Formation as Fracture Mechanism in Nanocomposites of Epoxy and Fullerene-Like WS2(Sumy State University, 2015) Haba, D.; Barbezat, M.; Brunner, A.J.Fullerene-like WS2 (IF-WS2) nanoparticles (NPs) were used as a toughening agent in epoxy nanocomposites. Already 0.5 % IF-WS2 by mass increased the critical energy release rate GIc by 45 % to 62 %. Conicsection-shaped crack lines were observed on the fracture surfaces in some distance to the NPs. Nanomechanical AFM modulus measurements showed, however, no measurable differences between the modulus distribution in the vicinity of the NPs and the bulk epoxy. Possible secondary crack formation at the NPs explains the crack lines nicely. The crack line geometry allows determining the relative velocity of the secondary crack. Topographic AFM showed vertical steps several hundred nanometers high at the crack lines, indicating shear fracture and suggesting the presence of numerous subsurface cracks, which might explain the toughness increase.Item A self-assembly of nanoparticles(Sumy State University, 2014) Ющенко, Ольга Володимирівна; Ющенко, Ольга Владимировна; Yushchenko, Olha Volodymyrivna; Бадалян, Анна Юріївна; Бадалян, Анна Юрьевна; Badalian, Anna Yuriivna; Bratash, S.O.Nanotechnology achievements are often connected to material science because the design of a wide range of advanced nanostructured materials will reduce the size of the components of many devices. But nanoscience today is more interested in the formation of nanoassemblies and further coupling of them into the nanostructured materials.Item Magnetic Properties of the Cobalt Ferrous Spinel Ferrite Nanoparticles Formed on the Steel Surface Contacting with Cobalt Chloride Water Solutions in Open-air System(Sumy State University, 2012) Lavrynenko, O.M.; Dudchenko, N.; Brik, A.B.The paper describes creation of cobalt ferrous spinel ferrite nanoparticles and investigation of their phase composition, surface structure and magnetic properties. Cobalt ferrous spinel ferrite nanoparticles were synthesized in an aerated system of steel electrode contacting with aqueous cobalt chloride at different pH values of solution. According to X-Ray diffraction data, it was shown, that some impurity phases also formed during the synthesis process, notably, lepidocrocite and goethite on the steel surface and Green Rust I, cobalt hydroxide, heterohenite in the solution. The quantity of such phases depends on pH value of initial solution. The size of synthesized cobalt ferrous spinel ferrite nanoparticles was approximately 10 – 12 nm. Saturation magnetization of synthesized cobalt ferrous spinel ferrite nanoparticles is rather high. Synthesized magnetic cobalt ferrous spinel ferrite nanoparticles are promising for different medicalbiological applications. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35307Item Influence of Ultrasound Treatment on the Properties of Synthetic Magnetite Nanoparticles(Sumy State University, 2013) Dudchenko, N.O.; Brik, A.B.; Kardanets, Y.V.; Grechanivskyy, O.E.The paper describes creation of magnetite nanoparticles under ultrasound treatment and investigation of their phase composition and magnetic properties. Magnetite nanoparticles were synthesized via coprecipitation of Fe+2 and Fe+3 with KOH in aqueous solution at 80°C. It was shown, that ultrasound treatment of solution during the synthesis of magnetite nanoparticles leads to the increasing of size and saturation magnetization obtained nanoparticles. The results of X-ray diffraction measurements show that the synthesized particles consist of magnetite. The size of synthesized magnetite nanoparticles according to Xray diffraction measurements was approximately 10 nm. Saturation magnetization of synthesized magnetite nanoparticles is rather high (37 A*m2/kg). Synthesized magnetite nanoparticles are promising for different medical-biological applications. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35186Item Effective Landau-Lifshitz-Gilbert equation for a conducting nanoparticle(Сумський державний університет, 2013) Денисов, Станіслав Іванович; Денисов, Станислав Иванович; Denysov, Stanislav Ivanovych; Бабич, Ганна Валеріївна; Бабич, Анна Валерьевна; Babych, Hanna ValeriivnaWe study the role of conductivity in the magnetization dynamics of single-domain ferromagnetic particles. Our approach is based on the coupled system of Maxwell’s and Landau-Lifshitz-Gilbert (LLG) equations. We show that the effective LLG equation for a conducting particle contains two additional terms compared to the ordinary LLG equation. One of them is responsible for the conductivity contribution to the damping parameter. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/33504Item Microbial synthesis of silver nanoparticles by streptomyces glaucus and spirulina platensis(Sumy State University, 2011) Tsibakhashvili, N.Ya; Kirkesali, E.J.; Pataraya, D.T.; Gurielidze, M.A.; Kalabegishvili, T.L.; Gvarjaladze, D.N.; Tsertvadze, G.I.; Frontasyeva, M.V.; Zinicovscaia, I.I.; Wakstein, M.S.; Khakhanow, S.N.; Shvindina, N.V.; Shklover, V.Ya.Microbial synthesis of nanoparticles has a potential to develop simple, costeffective and eco-friendly methods for production of technologically important materials. In this study, for the first time a novelactinomycete strain Streptomyces glaucus71 MD isolated from a soy rhizosphere in Georgiais for the first time extensively characterized and utilized for the synthesis of silver nanoparticles. Scanning Electron Microscope (SEM) allowed observing extracellular synthesis of nanoparticles, which has many advantages from the point of view of applications. Production of silver nanoparticles proceeded extracellularlywith the participation of another microorganism, bluegreen microalgae Spirulinaplatensis (S. platensis). In this study it is shown that the production rate of the nanoparticles depends not only on the initial concentration of AgNO3 but also varies with time in a nonmonotonic way. SEM study of silver nanoparticles remaining on the surface of microalgae revealed that after 1 day of exposure to 1 mM AgNO3 nanoparticles were arranged as long aggregates along S. platensiscells strongly damaged by silver ions. However, after 5 days of exposure to silver S. platensiscells looked completely recovered and the nanoparticles were distributed more uniformly on the surface of the cells. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/20679