E. N. Domoroshchina

Russian Technological University - RTU MIREA, Russia · Laboratory of Materials science of functional objects with different dimensions, Center "Multiscale Material Design"

In this work, the analysis and generalization of data on the elemental, phase and surface composition, crystal structure and microstructure of MFI-type HZSM-5 with Si/Al = 12, 25, 40, 300 were presented. Relationships between HZSM-5 silicate modulus (Si/Al) and pore volume, specific surface, the area of framework voids were established. Data obtain...

For the first time the neutron diffraction study of HZSM-5 zeolites with the general composition of (H¹⁺x)[Al³⁺xSi⁴⁺12-xO24] × wH2O in the orthorhombic approximation (sp. gr. Pnma, z = 8) and initial silicate modules Si/Al = 12, 25, 40 was carried out. As a result, the composition was refined, the distribution of Al³⁺ ions over the tetrahedral site...

For the first time catalytic systems based on HZSM-5 zeolites (Si/Al=12, 25, 40) with nanosized anatase (NA) were obtained in situ by a modified hydrothermal method and a sol-gel method. Initial HZSM-5 and NA/HZSM-5 were characterized (XRPD, XAS, FT-IR, DSC, BET, XPS, SEM, TPD) and analyzed in the reactions of propane (liquefied petroleum gas) conv...

HZSM-5 (MFI type) of composition (Hx)[Al3+xSi12−xO24] × wH2O and nanocomposites NA/HZSM-5, NA:M/HZSM-5 (NA—nanoscale anatase; M = V, Ni, Ag) with Si/Al = 12, 25, 40, 300 (sp.gr. Pnma or P21/n; z = 8), as well as zeolites [(Ti4+xSi12−xO24] × wH2O (TS) with Si/Ti = 47, 53, 73.5 (sp.gr. Pnma) were studied by XRPD, XAS, FTIR-spectroscopy, BET, XPS, SEM...

New NT:M/zeolite composites with functional nanoparticles of titanium(IV) oxides NT (-phase and anatase) have been prepared by introducing nitrates with dopant metals (M = Ag, Ni, V) and zeolites (H-Beta...

Anatase–mordenite nanocomposite was synthesized in situ and characterized by X-ray diffraction analysis, Brunauer–Emmett–Teller measurements, infrared (IR) spectroscopy, electron diffraction measurements, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy. It was found that X-ra...

Zeolite Y and the NTD/Y nanocomposite, which were synthesized in situ (the addition of zeolite Y to the reaction mixture in the course of the synthesis of NTD by the sulfate method), were studied by a variety of methods. The decrease in the particle size (scanning electron microscopy) and the water content in pores (X-ray powder diffraction study,...

NT/zeolite nanocomposites (NT - nanosized titanium(IV) oxides: η-phase and Hombifine N with anatase; zeolite: Beta(25), ZSM-5 with different modules Si/Al, MOR, or Y) have been obtained by two methods: modified cold-impregnation method (method 1) and in situ method of introduction of zeolites into the reaction mixture during the synthesis of NT by...

Synthesis conditions are optimized to obtain η-phase/zeolite and Hombifine N/zeolite nanocomposites by the modified cold-impregnation method (method 1), which consists of the codispersion of the samples containing the η-phase or Hombifine N with nano-anatase in a dilute KOH solution, and Beta(25) and ZSM-5 zeolites with different modulus, MOR and Y...

Nanocomposites based on a thermoplastic elastomer (TPE) (low-density polyethylene (LDPE) and 1,2-polybutadiene in a ratio of 60/40) with functional titanium dioxide nanoparticles of different nature, TiO2/TPE, have been prepared and investigated by a complex of methods (X-ray diffraction analysis using X-ray and synchrotron radiation beams, scannin...

The samples with nano-titanium dioxide (X-ray amorphous, η-modification, Degussa P25 mixture of rutile and anatase, Hombifine N, and Hombikat UV100 with anatase) and hexagonal nano-ZnO both in pure form and as a part of polystyrene (PS) nanocomposites were studied for antibacterial activity in the dark against Staphylococcus aureus, Staphylococcus...

Nanocomposites TiO2/SiO2 with photocatalytic and adsorptive properties were prepared by codispersing of η-modification and anatase (commercial Hombifine N) and SiO2 (opal, granules, ultrafine) in ethanol (or ethanol–water mixture in the presence of chlorophylls or porphyrins) with ultrasonic treatments of the mixture (method 1) and an aqueous solut...

This study produced for the first time composites based on polystyrene microspheres with nano-sized titania synthesized by sulfate and sol-gel methods, as well as commercial Hombifine N, Hombikat UV100, and Degussa P25. The starting samples and the composites were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption...

Nanosized titanium dioxide modifications are used in catalysis (for extraction of uranium compounds from sea water and producing hydrogen), sorption (for purification of aqueous media from a wide range of toxic ions), medicine (excellent cleaner of water and air environments from organic pollutants and bacteria), microelectronics (promising for sol...

Effect of nano-sized titania (NST) prepared by sulfate technique (anatase and η-TiO2) and commercial Degussa P25 on properties of their composites with 1,2-polybutadiene (1,2PB) is studied by a complex of methods. Mixtures were prepared with LB 300 160/160 laboratory rolls by stirring for 10 min. Elastomer was first modified with a curative group (...

Adsorption of Mo(VI) and W(VI) ions from water with nanosized anatase has been studied. This process depends on sorption conditions (temperature, contact duration, etc.) and sample characteristics (composition, specific surface area, coherent scattering regions, etc.). Maximal recovery efficiency for Mo(VI) and W(VI) was achieved with the use of th...

The development of materials with radically new properties is inextricably related with obtaining of nanoscale systems. One of the most promising materials in this area is TiO 2. Its nano-modifications are unique due to the formation of self-generating surface OH groups with a high reaction activity. From the 13 known stable and metastable modifica...

Langanite (La3Ga5.5Nb0.5O14, growth atmosphere: 99% Ar + 1% O2) and kanigasite (Ca3NbGa3Si2O14, growth atmosphere: 100% Ar) crystals grown by the Czochralski technique in Ir crucibles along <0001> direction have been firstly investigated by neutron diffraction. The difference between the compositions of upper (La2.935(2)□0.065)(Ga0.450Nb0.550(3))Ga...

Langatate crystals grown by the Czochralski method in 〈0001〉 and 〈011〉 directions both without subsequent annealing (from colorless to orange crystals) and with vacuum (colorless and pale-green crystals) and air (orange crystal) annealing have been investigated by neutron diffraction, X-ray diffraction and optical spectroscopy. The main types of po...

Single crystals of langasite (La3Ga5SiO14 - LGS, La3Ga5.5M0.5O14 – LGM (M=Ta,Nb), Ca3NbGa3Si2O14 - CNGS) and scheelite ((Na0.5R0.5)MO4 – NRM (R= La,Gd, M= Mo,W)) families were grown by the Czochralski technique. Single crystals of sillenite family (Bi24M2O40 – BMO) were grown by the hydrothermal technique. It was established the possibility of chan...

Langatate crystals (La3Ga5.5Ta0.5O14, LGT) are one of the most promising materials for application in acoustoelectronics. LGT have been generally grown by the Czochralski method using an iridium crucible. In [1] suggested that the color of as-grown LGT crystals is associated with the presence of iridium ions in the crystal composition but it is ref...

La3(Ga0.5Nb0.5)Ga5O14 (LGN) and La3(Ga0.5Ta0.5)Ga5O14 (LGT) are a promising piezoelectric material belonging to the family of langasite (La3Ga5SiO14, LGS) (sp. gr.P321, Z=1). In comparison with LGS and LGT crystals, LGN have higher values of relative dielectric coefficients (ε11/ε0 = 19.4; ε33/ε0 = 68.5) and piezoelectric constants (d11 =7.41±0.2 К...

Langatate crystals of the general composition La3(Ga0.5Ta0.5)Ga5O14, grown by the Czochralski method, have been investigated by neutron diffraction (single crystals) and X-ray diffraction (ground single crystals). The crystals were grown in an atmosphere of 99% Ar + 1% O2 in the Y54° direction (rotation by 54° with respect to the y axis), without s...

Crystals of langasite La3Ga4(GaSi)O14 grown by the Czochralski method are studied using neutron diffraction for the first time. It is established that the compositions of the upper and lower parts of an orange crystal grown from the La3Ga5.14Si0.86O14 seed in an (Ar + O2) atmosphere (the growth direction) can be written as(La2.85(2)&square;0.15)(Ga...

The frequency coefficient, an important performance parameter of piezoelectric materials, which is used in determining vibrational frequencies of crystalline piezoelectric elements, is shown to vary along the length of a crystal. The dependences of the frequency coefficient and elastic stiffness coefficient on unit-cell parameters have the form of...

Lattice parameters and crystal composition of langasite grown by the Czochralski method have been characterized in detail by X-ray diffraction (XRD) analysis. The crystal length-frequency coefficient dependence has been obtained. The frequency and elastic coefficients of langasite have been shown for the first time to be determined by the blocks di...

The temperature-dependent electrical conductivity and dielectric permittivity and room-temperature optical absorption spectra of La3Ga5SiO14 (langasite) crystals grown under different conditions are measured. The resistivity and peak-loss temperature t tanδ of the crystals are shown to be determined by the concentration of oxygen vacancies, which o...

The structure of langatate (as-grown and vacuum-annealed: LGT-I and LGT-II, respectively) and langanite (seed- and tail-end portions: LGN-III and LGN-IV, respectively) single crystals grown by the Czochralski technique from charges of nominal composition La3Ga5.5M0.5O14 = La3(Ga0.5M0.5)(1)Ga3(2)Ga2(3)O14 (M=Ta5+, Nb5+) is studied by x-ray diffracti...

A Czochralski-grown langasite family crystals of La3Ga5SiO14–La3Ga4(GaSi)O14, La3Ga4[Ga(Si,Ge)]O14, La3Ga5.5Ta0.5O14, La3Ga5.5Nb0.5O14, and Ca3NbGa3Si2O14 were studied by X-ray diffraction. Our results show that the composition of crystals may vary both axially and radially. The two solid solutions isostructural with langasite, which were identifie...

In the growing process of multicomponent piezocrystalline crystals (La₃Ga₅SiO₁₄), even minor deflections from optimal growth conditions lead to changes in defect concentration and, consequently, to changes in the properties of the whole crystal. A comprehensive study of the crystalline lattice using X-ray structural...

A Czochralski-grown langasite, La3Ga5SiO14 (La3Ga4(GaSi)O14), crystal was studied by x-ray diffraction. The crystal was found to consist of two isostructural solid solutions, except in the center of the tail end. The solid solutions differ in the Ga and Si occupancies on the (Ga,Si) site: Ga > Si in solid solution I, and Si > Ga in solid solution I...

A Czochralski-grown langasite, La3Ga5SiO14 (La3Ga4(GaSi)O14), crystal was studied by x-ray diffraction. The crystal was found to consist of two isostructural solid solutions, except in the center of the tail end. The solid solutions differ in the Ga and Si occupancies on the (Ga,Si) site: Ga > Si in solid solution I, and Si > Ga in solid solution I...