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Research on deposition of silver nanoparticles at the cellulose/NaNO3 electrolyte interface

Janusz Władysław, Kowalska Klaudia, Skwarek Ewa

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 4

art. no. 173554

EN

Currently the research on silver nanoparticles is of great demand owing to their antibacterial properties. One of the possibilities is the study of the silver deposition on the cellulose fibers, and more specifically of the silver nanoparticles and cellulose particles. The research was aimed at obtaining silver nanostructures by reducing ions with formaldehyde and then stabilizing them with the Pluronic solution. A suspension system containing cellulose fibers and silver nanoparticles was prepared in the basic electrolyte NaNO3. There were analyzed the following makes: pH of solutions, grain distribution and zeta potential ζ. Ag nanoparticles are largely applied in medicine, pharmacy, cosmetology and textile industry. Great interest in the nanostructures allows for developing knowledge about them, and thus creating the possibility of further improvement of their properties for subsequent applications.

2

Structure of aluminosilicate-supported nickel and iron oxides nanocomposites in gaseous and aqueous media

Goncharuk Olena, Dyachenko Alla, Skwarek Ewa, Ischenko Olena, Andriyko Lyudmila, Borysenko Mykola, Sulym Iryna, Sternik Dariusz, Kowalska Klaudia, Marynin Andrii

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 2

art. no. 144375

EN

A series of mixed oxides was synthesized by deposition of a guest phase on a highly dispersed oxide matrix. Fumed nanooxides SiO2, Al2O3, SiO2/Al2O3, and SiO2/Al2O3/TiO2 with the specific surface area of 65-91 m2/g were selected as highly dispersed matrices. NiO/FexOy was deposited as a guest oxide using solvate-stimulated modification of a surface of fumed nanocarriers with nickel nitrate and iron(III) formate and subsequent heat treatment up to 600 °C to form NiO/FexOy. The aim of this work was to study the influence of the composition and structure of fumed oxide matrices and deposited guest phase on the behavior of the composites in gaseous and aqueous media using XRD, nitrogen adsorption and SEM/EDX, and quasi-elastic light scattering (QELS) methods. The lowtemperature nitrogen adsorption isotherms have a sigmoid shape with a narrow hysteresis loop characteristic of mesoporous materials. The specific surface area of composites varies from 65 to 120 m2/g. SEM data show denser aggregate structure of nanocomposites compared to the initial carriers. The primary particle size was in the 30-60 nm range. According to QELS data, there is a tendency to form aggregates of 100 nm - 10 µm in size in the aqueous media. The XRD method shows that the deposited metal oxides are in the form of crystalline phases of NiO with crystallites of 7-23 nm in size, but the iron oxide reflexes were not identified for NiO-containing composites.

3

Sorption of ammonium and phosphate ions from aqueous solutions by carbon and mineral sorbents

Zakutevskyy Oleg, Shaposhnikova Tatyana, Kotynska Lyudmila, Biedrzycka Adrianna, Skwarek Ewa

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 4

art. no. 150285

EN

A search for a sorbent capable of simultaneously extracting both phosphate anions and ammonium cations from a highly competitive medium like the biological environment of the human’s body was realized. For this purpose a comparative study of a sorption of ammonium and phosphate ions from aquatic environments in the absence of any backgrounds electrolytes and from Ringer's solution by activated charcoal, its oxidized forms and mineral amorphous sorbents – powdered titanium silicate, as well as spherically granular hydrous zirconium silicate and titanium dioxide, obtained by original methods of synthesis, as well as some of their ion-substituted forms in comparison with commercially available silica gel was carried out. The features of the sorption of ammonium cations and phosphate anions by the studied sorbents are discussed. It was established that sorption properties of the sorbents depend strongly from their chemical nature. It determines a selectivity of ion-exchange and a possibility of chemosorption processes in Ringer's solution. A relationship between the sorption of calcium cations and phosphate anions from Ringer's solution was supposed which made it possible to assume the chemosorption mechanism. Based on the sorption mechanism understanding the sorption properties of titanium silicate with respect to phosphate anions were considerable improved by converting the initial sample into Ca- and Ce-ion-substituted forms without significant loss of its high sorption properties toward ammonium cations

4

Some applications of barium titanate prepared by different methods

Sydorchuk Volodymyr, Khalameida Svitlana, Skwarek Ewa, Biedrzycka Adrianna

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 2

art. no. 147192

EN

The paper presents some application of barium titanate synthesized by different methods. Barium titanate samples were prepared by four procedures: solid state, mechanochemical as direct synthesis and modification as well as hydrothermal and microwave. The obtained samples were systematically studied using X-ray diffraction, nitrogen adsorption, Fourier transform infrared spectroscopy (FTIR), potentiometric titration, and quasi-elastic light scattering and zeta potential measurements. The values of pHpzc (point of zero charge) and pHIEP (isoelectric point) characteristic of the electrical double layer were determined. The prepared samples were tested as photocatalysts under visible light. As a result, relationship between the conditions of barium titanate synthesis, its physicochemical and electrokinetic parameters, as well as photocatalytic activity under visible light was first established.

5

Adsorpcja dwuwartościowych kationów na granicy faz hydroksyapatyt/roztwór elektrolitu

Janusz Władysław, Skwarek Ewa

Wiadomości Chemiczne

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2021

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[Z] 75, 9-10

1203--1228

EN

Functional and composite materials obtained from hydroxyapatite (HAp) are widely used in practice, which results in intensive research of systems containing hydroxyapatite. Doping with divalent ions of hydroxyapatite changes its properties, thus extending its application in material science. Substitution of calcium ions in the surface layer of hydroxyapatite by metal cations is used in the development of new catalysts, sorbents, sensors and materials for other applications. The doping of the surface of the hydroxyapatite with divalent ions may occur as a result of adsorption of metal cations on the surface groups and calcium exchange in the crystal structure of the hydroxyapatite. The paper presents the mechanisms of adsorption of selected bivalent ions Ba2+, Cd2+, Co2+, Fe2+, Sr2+, Zn2+ on hydroxyapatite. The influence of cation adsorption on unit cell parameters, crystallite size and particle size distribution is discussed.

6

Synthesis of citrates of selected lanthanides (Er, Ho and Lu)

Janusz Władysław, Pikus Stanisław, Skwarek Ewa, Olszewska Elżbieta

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 6

225--234

EN

Holmium, erbium and lutetium citrates can be synthesized by transforming freshly precipitated holmium, erbium and lutetium hydroxides in the citric acid solution under the hydrothermal conditions (above 100 ℃) after 3 days of reaction. In this paper in order to determine the synthesis conditions, the hydroxide and citrate stability areas of selected lanthanides were compared. The studies of the structure of the obtained holmium citrate, erbium and lutetium samples showed that these compounds crystallize in a monoclinic system. The crystallite sizes determined by the HalderWagner method were 67.8 ± 8.0nm, 103.7 ± 4.5nm and 68.1 ± 4.2nm, respectively for the holmium citrate, erbium citrate and lutetium citrate samples. The shifts of the hydroxyl and carboxyl groups of citric acid in the FTIR spectrum indicate the interactions of both groups with holmium, erbium and lutetium cations. Then the obtained samples were subjected to the analysis of composition, and their particle size distribution was determined.

7

Preparation of yttrium citrate by the reaction of yttrium hydroxide with sodium citrate

Janusz Władysław, Skwarek Ewa, Sternik Dariusz

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 6

51--59

EN

A method of obtaining yttrium citrate by transformation of freshly precipitated yttrium hydroxide in the solutions of sodium citrate under hydrothermal conditions has been proposed. To determine the synthesis time, transformation kinetics consisted in by taking the solid samples for the C and H contents analysis after 6, 12, 24, 48 and 72 hours of synthesis. Simultaneously these samples were subjected to the thermogravimetric analysis. As follows from the thermogravimetric analysis adsorption of citrate dihydrate on yttrium hydroxide is observed in the initial period up to 24 hours. Later the yttrium citrate dihydrate is formed. The thermogravimetric analysis of the final product i.e. amorphous yttrium citrate showed that the decomposition/oxidation of the sample occurs in six stages the particle size analysis method of static light scattering showed that 45% of the particles had a diameter of 0.1-0.9 µm and 55% of particles with sizes from 0.9 to 5 µm.

8

The effect of hydrothermal modification of titanium phosphate on the adsorption affinity towards cadmium ions

Janusz Władysław, Khalameida Svietlana, Skwarek Ewa, Sydorchuk Vladimir, Charmas Barbara

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 6

1568--1576

EN

The effect of hydrothermal treatment of the gel or xerogel oftitanium phosphate (TiP) sample on the surface properties was studied usingthe EDS and FTIR ATR methods. The results show that the hydrothermal treatment of initial titanium phosphate decreases the amount of physically adsorbed water but increases the surface concentration of phosphate groups. Supplementary measurements of electrokinetic properties of modified and hydrothermally modified titanium phosphate samples confirmed an increase of the concentration of acidic groups on theTiP surface. The adsorption affinity of titanium phosphate towards cadmium ions was discussed. It was found that at a low initial concentration of cadmium ions adsorption affinity increases as a resultof hydrothermal treatment of TiP gel.

9

Synthesis and selected physicochemical properties of hydroxyapatite and white clay composite

Broda Ewa, Skwarek Ewa, Payentko Victoria V., Gunko Vladimir M.

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 6

1475--1483

EN

Hydroxyapatite (HAP) composites are very important biomaterials, which can be applied in various life areas. HAP composite with white clay was prepared and studied using X-ray diffraction, nitrogen adsorption, Fourier transform infrared spectroscopy (FTIR), potentiometric titration, and quasi-elastic light scattering and zeta potential measurements. The values of pHpzc (point of zero charge) and pHIEP (isoelectric point) which characterize the electrical double layer depend strongly on the white clay addition to HAP. Comparative studies of hydroxyapatite, white clay and composite using nitrogen adsorption and FTIR methods showed that in most cases composite has the properties nearly intermediate between hydroxyapatite and white clay taken for the synthesis; however, certain non- additivity was observed analyzing the properties, due to precipitation of HAP onto clay particles that changes the HAP formation conditions in comparison to HAP formation alone. Thus, changes in the condition of the composite preparation allow one to control the properties of the final materials.