Ivan Mironyuk

Vasyl Stefanyk Precarpathian National University · Department of Chemistry

The adsorption of yttrium cations from an aqueous solution of YCl3 by sodium-modified titanium dioxide (Na-TiO2) was investigated. The Na-TiO2 was obtained by impregnating Na+ cations into the surface layer of TiO2 nanoparticles. The synthesis of nanoparticle TiO2 was performed by a liquid-phase sol-gel method, using the aqua complex of [Ti(OH2)6]3...

This work describes the developed methods for determining the age of 90 Sr-90 Y β-source. The paper presents a literary description of the scientific problem, as well as presents two fundamentally different methods for dating radioactive 90 Sr-90 Y β-source. The first method of age dating of the 90 Sr-90 Y β-source is based on the chemical separati...

The adsorption of Sr(II) cations by Boron-doped TiO2 was investigated. The adsorbent samples were obtained by liquid-phase sol-gel method using the aqua complex precursor [Ті(ОН2)6]3+‧3Cl- and modifying reagent hydrogen borate Н3ВО3. It was found, that single-phase rutile titanium dioxide or two-phase anatase-rutile oxide materials were formed unde...

Silicon carbide is an extremely hard material that exhibits exceptional corrosion resistance as well as thermal shock resistance. Its high mechanical properties determine the increased performance of materials based on it. The combination of high thermal conductivity and low thermal expansion coefficient determines the stability of silicon carbide...

Thermolytic decomposition in a chloride-acid medium of a titanium aquacomplex precursor solution [Ti(OH2)6]3+•3Cl¯ as a result of its boiling at a temperature of (110-114) 0С is accompanied by precursor hydrolysis and the formation of hydrate molecules Ti(OH)3Cl•2Н2О, which, as a result of condensation, provide the formation of rutile ТіО2 with rod...

This paper is devoted to the adsorption capacity of titanium silicate toward Ba²⁺ cations. Titanium silicate can be synthesized from titanium production waste by sol-gel synthesis, which is of additional benefit to environmental protection. The determination of the surface area of the adsorbent was performed by the method of low-temperature N2 adso...

The phase composition and morphology of boron-containing TiO2 nanoparticles obtained by the sol-gel method were investigated. The solution of titanium aqua complex [Ti (OH2)6] 3+ ‧ 3Cl-was used as a precursor. Borate acid Н3ВО3 (promoter of the formation of rutile) was used as a modified reagent. A single-phase rutile TiO2 was obtained at a concent...

The chemical and radiation stability of titanium dioxide with surface arsenate groups during ⁹⁰Sr adsorption has been studied. The oxalate technique has been used to obtain a solution containing ⁹⁰Sr from the objects of the aquatic environment of the Chornobyl Exclusion Zone. The dependence of the strontium adsorption on the acidity of the solution...

Abstract. The aim of this work is the application of well-known adsorbents for the separation of 90Sr, 90Y, and 90Zr radionuclides. Three basic types of adsorbents have been studied: Dowex HCR S/S cation exchange resin, Dowex 1x8 anion exchange resin, and titanium dioxide with a chemically modified surface. The most effective adsorbent for the sepa...

The main features of measuring the trace amount of 90Sr using ICP-MS in ecology and nuclear forensics were established. Among them are sample-specific matrix effects which may enhance or suppress the analyte signal, spectroscopic interferences,poly-ions formation, isobaric interferences, and reagent contaminations. Proposed solutions to these probl...

This work is devoted to the study of the adsorption of strontium, yttrium, and zirconium ions by the strong acid cation exchange resin Dowex HCR-s/s. The adsorption of strontium, yttrium, and zirconium ions in batch and dynamic conditions from individual solutions of the studied elements, as well as from their mixture, was studied. It was shown tha...

The electrochemical processes in capacitor systems based on porous carbon materials (PCMs) derived from glucose, lactose, and saccharose at activation temperature of 800 and 1000°C are explored using impedance spectroscopy method. An equivalent electric circuit, which allows modeling of the impedance spectra in the frequency range from 10-2 to 105...

This work studies the adsorption of zirconium ions by mesoporous titanium dioxide with surface arsenate groups. Experimental maximal adsorption values of zirconium ions were found to be 109.6 mg/g in neutral medium. This process depends on the interaction time, the equilibrium concentration of zirconium ions, and the acidity of the solution. Adsorp...

This work studies the adsorption of zirconium ions by mesoporous titanium dioxide and by sodium-modified mesoporous titanium dioxide. Experimental maximal adsorption values of zirconium ions by H-TiO2 and Na-TiO2 were found to be 64 mg/g and 109,5 mg/g respectively. This process depends on the interaction time, equilibrium concentration of zirconiu...

Dependence of zirconium adsorption value on agitation time, solution acidity, equilibrium concentrations of zirconium cations, and zeolite NaX particle size was investigated. The two most common adsorption theories Langmuir and Freundlich, were used to analyzing equilibrium adsorption data. Nonlinear approximation shows that the Freundlich adsorpti...

This paper describes the testing of titanium dioxide, chemically modified by arsenate groups, as an adsorbent of 90 Sr from the component of aquatic ecosystems of the Chornobyl exclusion zone. It is shown, that the chemical composition of the aquatic environment impacts 90 Sr adsorption. The 4As-TiO 2 adsorbent reduces the activity of some samples...

This paper describes the testing of titanium dioxide, chemically modified by arsenate groups, as an adsorbent of 90Sr from the component of aquatic ecosystems of the Chornobyl exclusion zone. It is shown, that the chemical composition of the aquatic environment impacts 90Sr adsorption. The 4As-TiO2 adsorbent reduces the activity of some samples by...

This research evaluates the adsorption of yttrium from aqueous solutions by titanium dioxide with surface arsenate groups (4As-TiO2) and titanium dioxide with surface arsenate groups doped by neodymium (Nd/4As-TiO2). The impacts of various adsorption parameters such as contact time, pH and initial metal concentrations were investigated in batch ads...

New materials based on anatase modification TiO2 were proposed for 90Sr radiochemical separation from the environmental objects.

TiO2-based nanomaterials are attracting much attention in many areas, such as photocatalysis, photoelectricity, probing, electrochromism, photochromism, etc. They are widely used in paints, polymers, sunscreens, and toothpaste. There are various ways of synthesis that affect the size, shape, and crystallinity of TiO2 nanoparticles. The main methods...

The article explores the effect of citric acid as a pore-forming agent on the structure, morphology and electroconductive properties of porous carbon materials (PCMs) obtained from carbon precursor (saccharose) using the methods of small-angle X-ray scattering, low-temperature porometry and impedance spectroscopy. It was found that the volumetric f...

Experimental samples of mesoporous TiO2 with protonated and sodium-modified surfaces were obtained by sol-gel method. XRD, IR, X-ray fluorescence, and energy dispersive spectroscopy were used to characterize their crystalline structure, morphology and surface functional groups. The surface area of, and pore size distribution in the obtained samples...

The comparative analysis of atomic structure and morphology of fumed silica nanoparticles prepared under different synthesis conditions has been carried out using TEM, FTIR, quantum chemistry, and low-temperature nitrogen adsorption methods. It has been determined that the structure of amorphous silica nanoparticles is formed by branched chain-like...

Introduction shows the important of this scientific direction. 60 Co with half-life of 5.3 years is one of the few anthropogenic, gamma-emitting radionuclides, that can be detected in aquatic environments affected by liquid effluent discharged from nuclear facilities. The need for control of the content of 60 Co in the environment, determines the s...

In the present paper the mesoporous TiO 2 with chemosorbed carbonate groups was investigated as an adsorbent for the removal of Zn 2+ and Ba 2+ cations from aqueous solutions. The dependence of the adsorption values of Zn 2+ and Ba 2+ on the agitation time, solution's acidity, and modification of surface of TiO 2 was determined. The process of Zn 2...

In the present paper the mesoporous TiO2 with chemosorbed carbonate groups was investigated as an adsorbent for the removal of Zn2+ and Ba2+ cations from aqueous solutions. The dependence of the adsorption values of Zn2+ and Ba2+ on the agitation time, solution’s acidity, and modification of surface of TiO2 was determined. The process of Zn2+ and B...

The adsorption of yttrium was investigated in the butch mode, neutral medium in the range of 185 mg/L- 4202 mg/L equilibrium concentrations. The dependence of adsorption value of Y3+ ions by TiO2/Nd from time interaction, solution acidity and equillibrium concentration of yttrium ions was investigated. With the aid of a fluorescent X-ray analyzer,...

In this study, mesoporous carbonated TiO 2 nanoparticles were synthesized by sol-gel route using a complex [Ti(OH 2 ) 6 ] ³⁺ ·3Cl ⁻ and a modifying agent Na 2 CO 3 and used as an adsorbents for Sr(II) removal from aqueous medium. The characterization of nanoadsorbents was accomplished using XRD, SEM, EDS, TEM, TG-DTG-DTA, IR, BET, pH PZC analyses....

Mesoporous titania samples modified by sodium arsenate to form arsenate functionalities were synthesized using titanium aqua complex [Ті(ОН 2 ) 6 ] ³⁺ ·3Cl ⁻ and salt Na 3 AsO 4 as precursors. The structure, morphology, and texture of the samples were characterized using XRD, IR spectroscopy, TG-DTA, TEM, and nitrogen adsorption methods. The adsorp...

The nanostructured Zn-doped cobalt ferrites (Co1-xZnxFe2O4, where x ranges from 0.0 to 1.0 with the step of 0.1) were studied in order to elucidate the relation between their cationic distribution within the spinel sublattices and catalytic properties. The thermal transformation of the precursors (metal hydroxides) obtained through hydroxide co-pre...

Abstract. In present investigations, the sorption removal of Sr2+ and Y3+ ions from aqueous solutions by TiO2 – La sorbent was researched. The dependence of the sorption process on the time of interaction, solution’s acidity, and initial concentrations of the Sr2+ and Y3+ ions were investigated. Four simplified kinetic models – Lagergren’s pseudofi...

Cobalt-zinc ferrite nanoparticles of general formula Co 1-x Zn x Fe 2 O 4 (0.0 ⩽ x ⩽ 1.0) were synthesized by means of chemical co-precipitation method. Impedance analysis was used to study the grain and inter-grain conductivities. The changing of complex conductivity with composition confirmed the semiconducting behavior. A significant influence o...

Effect of swift heavy ion irradiation on MgFe2O4 (annealed at 450 °C/3 h) sample prepared by a sol–gel auto-combustion procedure has been studied. Single phase samples were irradiated with 120 MeV ²⁸Si⁹⁺ with ion fluence: 1 × 10¹¹, 1 × 10¹², and 1 × 10¹³ ions/cm² to monitor its effect on the structure, cation distribution, and magnetic properties....

The physic-chemical properties of ash extracted from smoke during the combustion of coal at the Burshtyn thermal power plant were investigated. The particles formed in the flame are crystallized glass beads with a size of 0.8–600 μm. It was found that the ash particles are heterogeneous in their chemical composition. The mass content of the ferric...

In present investigations, the sorption removal of Sr 2+ and Y 3+ ions from aqueous solutions by TiO 2-La sorbent were research. The dependence of sorption process on the time of interaction, solutions acidity, and initial concentrations of the Sr 2+ and Y 3+ ions was investigate. Four simplified kinetic models: Lagergren's pseudo-first and pseudo-...

Nanodispersed rutile with rod-like particles is synthesized by hydrolysis of TiCl4 in hydrochloric acid - ethanol alcohol aqueous solution. It is found that the specific surface area, crystallite size and degree of agglomeration are determined by molar ratio of ethanol in reaction medium. According to HR-TEM images and XRD data rutile crystallites...

The phenomenological model of sulphate anions effect on the nanodispersed titania synthesis during hydrolysis of titanium tetrachloride was studied. It was proposed that both chelating and bridging bidentate complexes formation between sulphate anions and octahedrally coordinated [Ti(OH)h(OH2)6−h](4−h)+ mononers is the determinative factor for anat...

Transformation of Al(NO 3 ) 3 ∙9H 2 O (upon heating in the range of 20–1200 °C) into blends of amorphous and crystalline boehmite (210–525 °C), amorphous alumina and crystalline γ-Al 2 O 3 (850 °C), and crystalline α-Al 2 O 3 (1100 °C) was analyzed using X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), infrared (IR...

Glucose, lactose, and saccharose were used as precursors to prepare chars at 400 °C then activated at 800 °C or 1000 °C in closed vessels with controlled amounts of oxygen penetrating through nanopores in the vessel walls. There are correlations between the porosity, amounts of residual O- and H-containing functionalities, and electroconductivity o...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Polymethylsiloxane (PMS) hydrogel (C(PMS)=10 wt%, soft paste-like hydrogel), diluted aqueous suspensions, and dried/wetted xerogel (powder) were studied in comparison with suspensions and dry powders of unmodified and silylated nanosilicas and silica gels using (1)H NMR, thermally stimulated depolarization current (TSDC), quasielastic light scatter...

Calcination of magnesium hydroxide, which was prepared from natural bischofite MgCl2·6H2O, leading to dehydration 2(MgOH) → MgOMg + H2O, is accompanied by transition of phase not only to MgO but also to MgOx at x < 1 (assigned to Mg4O3) at moderate temperatures. At higher temperatures, MgOx is completely transformed into MgO. Magnesium hydroxide an...

Several series of fumed silicas and mixed fumed oxides produced and treated under different conditions were studied in gaseous and liquid media using nitrogen and water adsorption–desorption, mass spectrometry, FTIR, NMR, thermally stimulated depolarization current (TSDC), photon correlation spectroscopy (PCS), zeta potential, potentiometric titrat...

Fumed silicas synthesized under varied conditions were studied by means of adsorption, ¹HNMR, photon correlation spectroscopy, and electrokinetic methods. Prepared silicas possess different specific surface area (SAr = 85-512 m²/g), structures of primary particles and their swarms, concentrations of silanols (COH = 1.9-5.2 µmol/m²), and weakly (Cw,...

Adsorption of Pb(II), Sr(II), and Cs(I) on fumed silica, alumina, titania, silica/titania (ST), silica/alumina (SA), and alumina/silica/titania (AST) reveals that mixed oxides containing titania have a greater adsorptive capability in respect to metal cations than individual and SA oxides. Pyrocarbon deposits on fumed oxides enhance the adsorption...

A series of fumed oxides such as silica, titania, alumina, silica/alumina (SA), silica/titania (ST), and alumina/silica/titania (AST), initial and hydrothermally treated (HTT) in the steam phase at T(HTT)=150, 250, and 350 degrees C was studied by adsorption, AFM, XRD, FTIR, and theoretical methods. Diminution of the size of primary particles (corr...

The structural characteristics of fumed silicas synthesised under varied conditions and standard fumed silicas subjected to different types of pre-treatment, such as heating, suspending–ball-milling–drying, ball-milling of dry powder, and immobilisation of polymers, were studied using adsorption–desorption methods. Variations of preparation conditi...

A variety of individual and mixed fumed oxides based on silica, alumina, and titania was studied in the gas phase and aqueous suspension by means of XRD, NMR, IR, UV, optical and photon correlation spectroscopies, electrophoresis, potentiometric titration, adsorption of metal cations, nitrogen, water, low-molecular drugs, and polymers (polyvinylpyr...

The polymorphic forms of silica (silicon dioxide; SiO(2)) interact with the cell membranes of many mammalian cells, including red blood cells (RBCs), causing hemolysis. The electrostatic factor, which is believed to be a major contributor to the silica-cell contact, might have potential interest for the study of cell surface properties. The surface...

Pristine fumed silica and powders with dried residuals of centrifuged aqueous suspensions of fumed silica, silica/PVP, or silica/protein were studied using nitrogen adsorption and IR spectroscopy methods. The aqueous suspensions of silica with added polymers, surfactant, or ethanol were investigated by means of photon correlation spectroscopy, 1H N...

Fumed silicas synthesized under varied conditions (stoichiometric or nonstoichiometric amounts of reactants SiCl4, O2 (mixed with N2), and H2, different burner diameter, flow velocity and turbulence, flame temperature, etc.) were studied using adsorption of nitrogen, argon, and water, infrared (IR) and photon correlation spectroscopy, 1H NMR, and e...

Fumed silicas synthesised with varied amounts of reactants (SiCl4,O2,H2) at the flame temperature of 1100–1400°C were studied using adsorption, infrared (IR), 1H NMR, dielectric relaxation (DRS) and photon correlation spectroscopy methods. These samples possess different specific surface area (100–410 m2 g−1), concentration of silanols (2.4–4.8 μmo...

The factors influencing stability of mixed water dispersions of hydrophilic and hydrophobic silicas have been investigated. It was shown that hydrophobic silica is kept in system in a stable state due to structural-mechanical barrier (SMB) formed by hydrophilic silica, which prevents coagulation of hydrophobic silica in a separate phase. Hydrophili...

The distribution of electrostatic potential in the vicinity of the hydroxylated and trimethylsilylated surface of silica was calculated in the semiempirical PM3 approximation. A new mechanism is proposed for the bonding of electron-donating molecules with the surface of hydrophobized silicas.

The influence of gasodynamic parameters of SiCl4 flame hydrolysis process on the formation of pyrogenic silica particles was investigated. The pyrogenic synthesis of silica (aerosil) occurs with the participation of multiple homolytic and heterolytic reactions. It is shown that dimensions of the initial particles and their aggregates can be regulat...

The effect of the consumption of hydrogen and air oxygen, as well as that of turbulence level of a gas stream on the physicochemical characteristics of highly-disperse pyrogenic silica have been studied. The varying these parameters has been determined to enable regulation of porous structure and hydrophilicity of silica surface. It is established...

The specific features of SiCl4-H2O transformations under stoichiometric proportions (via reaction SiCl4+2H2P→SiO2+4HCl) were discussed. It was shown that along with silanol groups condensation (which form under Si-Cl bond hydrolysis), a formation of siloxane groups by ≡SiOH and ≡SiCl reactions is a significant reaction channel. The process favors t...

A perspective technique that does not require considerable energy consumption was proposed for preparation of quartz-glass-like nonporous silica. The features of silicon tetrachloride hydrolysis with hydrochloric acid solution with stoichiometric SiCl4 to H2O ratio were analyzed in detail. The effect of reaction media temperature on chemical transf...

The influence of the reactive mixture composition and gas flow rate on physicochemical characteristics of prepared aerosils in pyrogenous synthesis of SiO2 was investigated. It is shown that the purposeful variations of synthesis conditions are reliable means of preparation of aerosils with given properties. The experiments were performed at the se...

Thermal structural transformations in samples of nanostructured silica and quartz glass prepared from this silica were studied. It is established that the structural changes in the crystalline silica modifications take place in the region of phase transitions. The data of crystallographic studies suggest that the silica and glass studied have a mic...

In the paper, the energetic parameters of silylation of silica surface were considered using the results of theoretical calculations and experimental data. A method of correlation between calculated and experimentally measured values of enthalpy of interaction of silica surface hydroxyl groups with bulk modifier molecules is proposed. A model of su...

The 1H NMR technique was used to study the hydration activity of hydrophilic (Aerosil A-300), methylated (MS) and mixed in a 5:1 ratio (MIX) silicas. It has been determined that the thickness of a layer of adsorbed water in an aqueous medium becomes higher for MS compared with that for A-300. The above phenomenon may be explained by polarization of...

As result of study of the dynamics of physico-chemical parameters and protein adsorption properties of aerosil at different stages of its production it has been established that the final product is characterizes by the highest indices of specific surface and protein adsorption ability. After standardization this product has been recommended as the...

Investigations have been made of changes in the structures of ultradisperse pyrogenic silica particles by small-angle X-ray scattering during dehydration and chemosorption. It has been established that during dehydration there are abrupt changes in the geometrical dimensions of the particles, caused by breakdown of coordination complexes between su...