28 results on '"Olga Yu. Fetisova"'
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2. Inherited Structure Properties of Larch Arabinogalactan Affected via the TEMPO/NaBr/NaOCl Oxidative System
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Vladislav A. Ionin, Yuriy N. Malyar, Valentina S. Borovkova, Dmitriy V. Zimonin, Roksana M. Gulieva, and Olga Yu. Fetisova
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larch ,arabinogalactan ,oxidation ,2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) ,flocculation ,Organic chemistry ,QD241-441 - Abstract
Arabinogalactan (AG), extracted from larch wood, is a β-1,3-galactan backbone and β-1,6-galactan side chains with attached α-1-arabinofuranosyl and β-1-arabinopyranosyl residues. Although the structural characteristics of arabinogalactan II type have already been studied, its functionalization using 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) oxidation remains a promising avenue. In this study, the oxidation of AG, a neutral polysaccharide, was carried out using the TEMPO/NaBr/NaOCl system, resulting in polyuronides with improved functional properties. The oxidation of AG was controlled by analyzing portions of the reaction mixture using spectrophotometric and titration methods. To determine the effect of the TEMPO/NaBr/NaOCl system, air-dried samples of native and oxidized AG were studied by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy, as well as by gel permeation chromatography. Compounds that model free (1,1-diphenyl-2-picrylhydrazyl (DPPH)) and hydroxyl radicals (iron(II) sulfate, hydrogen peroxide, and salicylic acid) were used to study the antioxidant properties. It was found that, in oxidized forms of AG, the content of carboxyl groups increases by 0.61 mmol compared to native AG. The transformation of oxidized AG into the H+ form using a strong acid cation exchanger leads to an increase in the number of active carboxyl groups to 0.76 mmol. Using FTIR spectroscopy, characteristic absorption bands (1742, 1639, and 1403 cm−1) were established, indicating the occurrence of oxidative processes with a subsequent reduction in the carboxyl group. The functionality of AG was also confirmed by gel permeation chromatography (GPC), which is reflected in an increase in molecular weights (up to 15,700 g/mol). A study of the antioxidant properties of the oxidized and protonated forms of AG show that the obtained antioxidant activity (AOA) values are generally characteristic of polyuronic acids. Therefore, the TEMPO oxidation of AG and other neutral polysaccharides can be considered a promising approach for obtaining compounds with the necessary controlled characteristics.
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- 2024
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3. ENERGY APPLICATION OF CARDBOARD IN MIXTURE WITH COAL
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Andrey V. Zhuykov, Olga Yu. Fetisova, Stanislav V. Chicherin, and Petr N. Kuznetsov
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hard coal ,cardboard ,biomass ,thermogravimetric analysis ,kinetics ,coates–redfern ,co-combustion ,Engineering geology. Rock mechanics. Soil mechanics. Underground construction ,TA703-712 - Abstract
The relevance of the study is determined by the search for new solid fuels to expand the fuel and energy complex and improve resource-saving and environmentally friendly energy. The main aim: a comprehensive study of cardboard and coal combustion, including the determination of the main characteristics of the combustion of solid fuel mixtures, the determination of the main kinetic parameters and the establishment of the role of the components in the mixture combustion. Object: solid fuel mixture based on Kaa-Khem coal and cardboard. Methods. Thermal characteristics of fuels are determined according to: analytical moisture – SS R 33503-2015; ash content – SS R 55661-2013; yield of volatile components – SS R 55660-2013; calorific value – SS R 147-2013; content of carbon, hydrogen, nitrogen – SS R 32979-2014; oxygen – SS R 27313-2015; sulfur – SS 8606-2015. The fuel combustion was studied using an SDT Q600 differential thermal analyzer (TA Instruments-Waters LLC, USA). Ignition and burnout temperatures were determined using the curve crossing method. To determine the kinetic characteristics of individual fuels and fuel mixtures, a method based on the Coates–Redfern model was used. Results. The heat of combustion of Kaa-Khem coal is twice that of cardboard, while the volatile content of cardboard is 1,8 times higher than that of coal, which makes cardboard a promising additional fuel. An increase in the mass fraction of cardboard in the mixture does not affect the ignition temperature of the mixture and is about 300 °С. The addition of 25 % cardboard to coal has a positive effect on coal carbon residue combustion, increasing the maximum reaction rate by 30 % compared to the calculated data. The activation energy in this case is reduced by 3 9%, the combustion index is reduced by 2,5 times. The results of this study can be applied in the design of new heat and power equipment, or be taken into account when converting coal-burning boilers to burning solid fuel mixtures.
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- 2023
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4. Fractionation of Aspen Wood to Produce Microcrystalline, Microfibrillated and Nanofibrillated Celluloses, Xylan and Ethanollignin
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Boris N. Kuznetsov, Anna I. Chudina, Aleksandr S. Kazachenko, Olga Yu. Fetisova, Valentina S. Borovkova, Sergei A. Vorobyev, Anton A. Karacharov, Elena V. Gnidan, Elena V. Mazurova, Andrey M. Skripnikov, and Oxana P. Taran
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aspen wood ,fractionation ,xylan ,ethanollignin ,microcrystalline ,microfibrillated and nanofibrillated celluloses ,Organic chemistry ,QD241-441 - Abstract
A new method for extractive-catalytic fractionation of aspen wood to produce microcrystalline (MCC), microfibrillated (MFC), nanofibrilllated (NFC) celluloses, xylan, and ethanollignin is suggested in order to utilize all of the main components of wood biomass. Xylan is obtained with a yield of 10.2 wt.% via aqueous alkali extraction at room temperature. Ethanollignin was obtained with a yield of 11.2 wt.% via extraction with 60% ethanol from the xylan-free wood at 190 °C. The lignocellulose residue formed after the extraction of xylan and ethanollignin was subjected to catalytic peroxide delignification in the acetic acid-water medium at 100 °C in order to obtain microcrystalline cellulose. MCC is hydrolyzed with 56% sulfuric acid and treated with ultrasound to produce microfibrillated cellulose and nanofibrillated cellulose. The yields of MFC and NFC were 14.4 and 19.0 wt.%, respectively. The average hydrodynamic diameter of NFC particles was 36.6 nm, the crystallinity index was 0.86, and the average zeta-potential was 41.5 mV. The composition and structure of xylan, ethanollignin, cellulose product, MCC, MFC, and NFC obtained from aspen wood were characterized using elemental and chemical analysis, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analyses, Gas chromatography (GC), Gel permeation-chromatography (GPC), Scanning electron microscopy (SEM), Atomic force microscopy (AFM), Dynamic light scattering (DLS), Thermal gravimetric analysis (TGA).
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- 2023
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5. Preparation and Characterization of di- and Tricarboxylic Acids-Modified Arabinogalactan Plasticized Composite Films
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Yuriy N. Malyar, Valentina S. Borovkova, Alexander S. Kazachenko, Olga Yu. Fetisova, Andrey M. Skripnikov, Valentin V. Sychev, and Oxana P. Taran
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polysaccharides ,arabinogalactan ,biofilms ,carboxylic acids ,cross-linking ,methylene blue ,Organic chemistry ,QD241-441 - Abstract
To ensure the high quality of water, it is necessary to remove toxic pollutants. At present, purification of water is implemented using various sorbents. The efficient sorption materials are modified polysaccharides. In this study, we report on a new environmentally friendly method for modifying larch hemicellulose—arabinogalactan (AG)—with polybasic carboxylic acids (citric, succinic, oxalic, and adipic) to obtain composite materials. The synthesized AG derivatives have been explored by a complex of physicochemical methods, including gel permeation chromatography (GPC), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffractometry (XRD), scanning electron microscopy (SEM), and sorption capacity investigations. It is shown that the heat treatment results in the formation of additional inter- and intramolecular bonds between carboxylic acids and polysaccharide molecules. The formation of ester bonds has been confirmed by the appearance of absorption bands in the IR spectra in the range of 1750–1690 cm−1. It has been found, using the TGA study, that the most thermally stable (up to 190 °C) sample is arabinogalactan oxalate obtained under heat treatment. The SEM study of the synthesized AG films has shown that the modified samples have the homogeneous film surface ensured by cross-linking. It has been established, when studying the sorption properties of the AG derivatives, that AG succinate (82.52%) obtained by lyophilization has the highest sorption capacity, due to the developed mesoporous surface, which, in turn, makes the synthesized films promising eco-friendly materials for use as drug carriers, sorbents, and water treatment agents.
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- 2023
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6. Sulfation of Birch Wood Microcrystalline Cellulose with Sulfamic Acid Using Ion-Exchange Resins as Catalysts
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Aleksandr S. Kazachenko, Natalia Yu. Vasilieva, Yaroslava D. Berezhnaya, Olga Yu. Fetisova, Valentina S. Borovkova, Yuriy N. Malyar, Irina G. Sudakova, Valentin V. Sychev, Noureddine Issaoui, Maxim A. Lutoshkin, and Anton A. Karacharov
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ion-exchange resin ,cellulose ,sulfamic acid ,catalysis ,sulfation ,Organic chemistry ,QD241-441 - Abstract
Cellulose sulfates are important biologically active substances with a wide range of useful properties. The development of new methods for the production of cellulose sulfates is an urgent task. In this work, we investigated ion-exchange resins as catalysts for the sulfation of cellulose with sulfamic acid. It has been shown that water-insoluble sulfated reaction products are formed in high yield in the presence of anion exchangers, while water-soluble products are formed in the presence of cation exchangers. The most effective catalyst is Amberlite IR 120. According to gel permeation chromatography, it was shown that the samples sulfated in the presence of the catalysts KU-2-8, Purolit s390 plus, and AN-31 SO42− underwent the greatest degradation. The molecular weight destribution profiles of these samples are noticeably shifted to the left towards low-molecular-weight compounds with an increase in fractions in the regions Mw ~2.100 g/mol and ~3.500 g/mol, indicating the growth of microcrystalline cellulose depolymerization products. The introduction of a sulfate group into the cellulose molecule is confirmed using FTIR spectroscopy by the appearance of absorption bands at 1245–1252 cm−1 and 800–809 cm−1, which correspond to the vibrations of the sulfate group. According to X-ray diffraction data, amorphization of the crystalline structure of cellulose is observed during sulfation. Thermal analysis has shown that with an increase in the content of sulfate groups in cellulose derivatives, thermal stability decreases.
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- 2023
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7. Kinetic Study of Pyrolysis of Coniferous Bark Wood and Modified Fir Bark Wood
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Olga Yu. Fetisova, Nadezhda M. Mikova, Anna I. Chudina, and Aleksandr S. Kazachenko
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coniferous bark wood ,modified fir bark wood ,pyrolysis ,thermogravimetric analysis (TGA) ,differential scanning calorimetry (DSC) ,activation energy ,Physics ,QC1-999 - Abstract
We report on the kinetics of pyrolysis of bark wood of four coniferous tree species: fir (Abies sibirica), larch (Larix sibirica), spruce (Picea obovata), and cedar (Pinus sibirica) denoted as FB, LB, SB, and CB, respectively. Thermogravimetry (TG) and differential scanning calorimetry (DSC) methods were used to study the influence of KCl and K3PO4 compounds on the process of thermal decomposition of fir bark and determine the main thermal effects accompanying this process. As a result of the studies carried out, it was found that KCl additives practically do not affect the decomposition of hemicelluloses, but they shift the maximum decomposition of the cellulose peak in the direction of decreasing temperature to 340.9 °C compared to untreated bark (357.5 °C). K3PO4 promotes the simultaneous decomposition of hemicelluloses and cellulose in the temperature range with a maximum of 277.8 °C. In both cases, the additions of KCl and K3PO4 reduce the maximum rate of weight loss, which leads to a higher yield of carbon residues: the yield of char from the original fir bark is 28.2%, in the presence of K3PO4 and KCl it is 52.6 and 65.0%, respectively. Using the thermogravimetric analysis in the inert atmosphere, the reaction mechanism has been established within the Criado model. It is shown that the LB, SB, and CB thermal decomposition can be described by a two-dimensional diffusion reaction (D2) in a wide range (up to 0.5) of conversion values followed by the reactions with orders of three (R3). The thermal decomposition of the FB occurs somewhat differently. The diffusion mechanism (D2) of the FB thermal decomposition continues until a conversion value of 0.6. As the temperature increases, the degradation of the FB sample tends to R3. It has been found by the thermogravimetric analysis that the higher cellulose content prevents the degradation of wood. The bark wood pyrolysis activation energy has been calculated within the Coats–Redfern and Arrhenius models. The activation energies obtained within these models agree well and can be used to understand the complexity of biomass decomposition.
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- 2023
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8. Microfibrillated Cellulose with a Lower Degree of Polymerization; Synthesis via Sulfuric Acid Hydrolysis under Ultrasonic Treatment
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Yuriy N. Malyar, Irina G. Sudakova, Valentina S. Borovkova, Anna I. Chudina, Elena V. Mazurova, Sergey A. Vorobyev, Olga Yu. Fetisova, Eugene V. Elsufiev, and Ivan P. Ivanov
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spruce wood ,microcrystalline cellulose ,sulfuric acid hydrolysis ,ultrasonic treatment ,microfibrillated cellulose ,Organic chemistry ,QD241-441 - Abstract
A new approach is being considered for obtaining microfibrillated cellulose with a low degree of polymerization by sulfuric acid hydrolysis with simultaneous ultrasonic treatment under mild conditions (temperature 25 °C, 80% power control). Samples of initial cellulose, MCC, and MFC were characterized by FTIR, XRF, SEM, DLS, and TGA. It was found that a high yield of MFC (86.4 wt.%) and a low SP (94) are observed during hydrolysis with ultrasonic treatment for 90 min. It was shown that the resulting microfibrillated cellulose retains the structure of cellulose I and has an IC of 0.74. It was found that MFC particles are a network of fibrils with an average size of 91.2 nm. ζ-potential of an aqueous suspension of MFC equal to −23.3 mV indicates its high stability. It is noted that MFC has high thermal stability, the maximum decomposition temperature is 333.9 °C. Simultaneous hydrolysis process with ultrasonic treatment to isolate MFC from cellulose obtained by oxidative delignification of spruce wood allows to reduce the number of stages, reduce energy costs, and expand the scope.
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- 2023
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9. Reductive Catalytic Fractionation of Abies Wood into Bioliquids and Cellulose with Hydrogen in an Ethanol Medium over NiCuMo/SiO2 Catalyst
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Boris N. Kuznetsov, Angelina V. Miroshnikova, Aleksandr S. Kazachenko, Sergey V. Baryshnikov, Yuriy N. Malyar, Vadim A. Yakovlev, Andrey M. Skripnikov, Olga Yu. Fetisova, Yong Xu, and Oxana P. Taran
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abies wood ,fractionation ,hydrogenation with hydrogen ,ethanol ,catalyst ,NiCuMo/SiO2 ,Chemical technology ,TP1-1185 ,Chemistry ,QD1-999 - Abstract
Noble metal-based catalysts are widely used to intensify the processes of reductive fractionation of lignocellulose biomass. In the present investigation, we proposed for the first time using the inexpensive NiCuMo/SiO2 catalyst to replace Ru-, Pt-, and Pd-containing catalysts in the process of reductive fractionation of abies wood into bioliquids and cellulose products. The optimal conditions of abies wood hydrogenation were selected to provide the effective depolymerization of wood lignin (250 °C, 3 h, initial H2 pressure 4 MPa). The composition and structure of the liquid and solid products of wood hydrogenation were established. The NiCuMo/SiO2 catalyst increases the yield of bioliquids (from 36 to 42 wt%) and the content of alkyl derivatives of methoxyphenols, predominantly 4-propylguaiacol and 4-propanolguaiacol. A decrease in the molecular mass and polydispersity (from 1870 and 3.01 to 1370 Da and 2.66, respectively) of the liquid products and a threefold increase (from 9.7 to 36.8 wt%) in the contents of monomer and dimer phenol compounds were observed in the presence of the catalyst. The solid product of catalytic hydrogenation of abies wood contains up to 73.2 wt% of cellulose. The composition and structure of the solid product were established using IRS, XRD, elemental and chemical analysis. The data obtained show that the catalyst NiCuMo/SiO2 can successfully replace noble metal catalysts in the process of abies wood reductive fractionation into bioliquids and cellulose.
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- 2023
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10. Comprehensive Study of the Ammonium Sulfamate–Urea Binary System
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Aleksandr S. Kazachenko, Noureddine Issaoui, Olga Yu. Fetisova, Yaroslava D. Berezhnaya, Omar M. Al-Dossary, Feride Akman, Naveen Kumar, Leda G. Bousiakou, Anna S. Kazachenko, Vladislav A. Ionin, Evgeniy V. Elsuf’ev, and Angelina V. Miroshnikova
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ammonium sulfamate ,urea ,density functional theory ,binary system ,quantum theory of atoms in molecules ,Organic chemistry ,QD241-441 - Abstract
The physicochemical properties of binary systems are of great importance for the application of the latter. We report on the investigation of an ammonium sulfamate–urea binary system with different component ratios using a combination of experimental (FTIR, XRD, TGA/DSC, and melting point) and theoretical (DFT, QTAIM, ELF, RDG, ADMP, etc.) techniques. It is shown that, at a temperature of 100 °C, the system under study remains thermally and chemically stable for up to 30 min. It was established using X-ray diffraction analysis that the heating time barely affects the X-ray characteristics of the system. Data on the aggregate states in specified temperature ranges were obtained with thermal analysis and determination of the melting point. The structures of the ammonium sulfamate–urea system with different component ratios were optimized within the density functional theory. The atom-centered density matrix propagation calculation of the ammonium sulfamate–urea system with different component ratios was performed at temperatures of 100, 300, and 500 K. Regardless of the component ratio, a regular increase in the potential energy variation (curve amplitude) with an increase in temperature from 100 to 500 K was found.
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- 2023
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11. An Efficient Method of Birch Ethanol Lignin Sulfation with a Sulfaic Acid-Urea Mixture
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Alexander V. Levdansky, Natalya Yu. Vasilyeva, Yuriy N. Malyar, Alexander A. Kondrasenko, Olga Yu. Fetisova, Aleksandr S. Kazachenko, Vladimir A. Levdansky, and Boris N. Kuznetsov
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birch ethanol lignin ,sulfamic acid ,urea ,sulfation process optimization ,sulfated product characterization ,FTIR spectroscopy ,Organic chemistry ,QD241-441 - Abstract
For the first time, the process of birch ethanol lignin sulfation with a sulfamic acid-urea mixture in a 1,4-dioxane medium was optimized experimentally and numerically. The high yield of the sulfated ethanol lignin (more than 96%) and containing 7.1 and 7.9 wt % of sulfur was produced at process temperatures of 80 and 90 °C for 3 h. The sample with the highest sulfur content (8.1 wt %) was obtained at a temperature of 100 °C for 2 h. The structure and molecular weight distribution of the sulfated birch ethanol lignin was established by FTIR, 2D 1H and 13C NMR spectroscopy, and gel permeation chromatography. The introduction of sulfate groups into the lignin structure was confirmed by FTIR by the appearance of absorption bands characteristic of the vibrations of sulfate group bonds. According to 2D NMR spectroscopy data, both the alcohol and phenolic hydroxyl groups of the ethanol lignin were subjected to sulfation. The sulfated birch ethanol lignin with a weight average molecular weight of 7.6 kDa and a polydispersity index of 1.81 was obtained under the optimum process conditions. Differences in the structure of the phenylpropane units of birch ethanol lignin (syringyl-type predominates) and abies ethanol lignin (guaiacyl-type predominates) was manifested in the fact that the sulfation of the former proceeds more completely at moderate temperatures than the latter. In contrast to sulfated abies ethanol lignin, the sulfated birch ethanol lignin had a bimodal and wider molecular weight distribution, as well as less thermal stability. The introduction of sulfate groups into ethanol lignin reduced its thermal stability.
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- 2022
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12. Colloidal and Immobilized Nanoparticles of Lead Xanthates
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Sergey A. Vorobyev, Svetlana V. Saikova, Svetlana A. Novikova, Olga Yu. Fetisova, Sergey M. Zharkov, Alexander S. Krylov, Maxim N. Likhatski, and Yuri L. Mikhlin
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Chemistry ,QD1-999 - Published
- 2019
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13. Sulfation of Wheat Straw Soda Lignin with Sulfamic Acid over Solid Catalysts
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Aleksandr S. Kazachenko, Feride Akman, Natalya Yu. Vasilieva, Yuriy N. Malyar, Olga Yu. Fetisova, Maxim A. Lutoshkin, Yaroslava D. Berezhnaya, Angelina V. Miroshnikova, Noureddine Issaoui, and Zhouyang Xiang
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lignin ,sulfation ,catalysts ,sulfated lignin ,DFT ,Organic chemistry ,QD241-441 - Abstract
Soda lignin is a by-product of the soda process for producing cellulose from grassy raw materials. Since a method for the industrial processing of lignin of this type is still lacking, several research teams have been working on solving this problem. We first propose a modification of soda lignin with sulfamic acid over solid catalysts. As solid catalysts for lignin sulfation, modified carbon catalysts (with acid sites) and titanium and aluminum oxides have been used. In the elemental analysis, it is shown that the maximum sulfur content (16.5 wt%) was obtained with the Sibunit-4® catalyst oxidized at 400 °C. The incorporation of a sulfate group has been proven by the elemental analysis and Fourier-transform infrared spectroscopy. The molecular weight distribution has been examined by gel permeation chromatography. It has been demonstrated that the solid catalysts used in the sulfation process causes hydrolysis reactions and reduces the molecular weight and polydispersity index. It has been established by the thermal analysis that sulfated lignin is thermally stabile at temperatures of up to 200 °C. According to the atomic force microscopy data, the surface of the investigated film consists of particles with an average size of 50 nm. The characteristics of the initial and sulfated β-O-4 lignin model compounds have been calculated and recorded using the density functional theory.
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- 2022
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14. Molecular Characteristics and Antioxidant Activity of Spruce (Picea abies) Hemicelluloses Isolated by Catalytic Oxidative Delignification
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Valentina S. Borovkova, Yuriy N. Malyar, Irina G. Sudakova, Anna I. Chudina, Andrey M. Skripnikov, Olga Yu. Fetisova, Alexander S. Kazachenko, Angelina V. Miroshnikova, Dmitriy V. Zimonin, Vladislav A. Ionin, Anastasia A. Seliverstova, Ekaterina D. Samoylova, and Noureddine Issaoui
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wood polysaccharides ,delignification ,hemicellulose ,antioxidant activity ,molecular weight distribution ,gel permeation chromatography ,Organic chemistry ,QD241-441 - Abstract
Spruce (Piceaabies) wood hemicelluloses have been obtained by the noncatalytic and catalytic oxidative delignification in the acetic acid-water-hydrogen peroxide medium in a processing time of 3–4 h and temperatures of 90–100 °C. In the catalytic process, the H2SO4, MnSO4, TiO2, and (NH4)6Mo7O24 catalysts have been used. A polysaccharide yield of up to 11.7 wt% has been found. The hemicellulose composition and structure have been studied by a complex of physicochemical methods, including gas and gel permeation chromatography, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The galactose:mannose:glucose:arabinose:xylose monomeric units in a ratio of 5:3:2:1:1 have been identified in the hemicelluloses by gas chromatography. Using gel permeation chromatography, the weight average molar mass Mw of hemicelluloses has been found to attain 47,654 g/mol in noncatalytic delignification and up to 42,793 g/mol in catalytic delignification. Based on the same technique, a method for determining the α and k parameters of the Mark–Kuhn–Houwink equation for hemicelluloses has been developed; it has been established that these parameters change between 0.33–1.01 and 1.57–472.17, respectively, depending on the catalyst concentration and process temperature and time. Moreover, the FTIR spectra of the hemicellulose samples contain all the bands characteristic of heteropolysaccharides, specifically, 1069 cm−1 (C–O–C and C–O–H), 1738 cm−1 (ester C=O), 1375 cm−1 (–C–CH3), 1243 cm−1 (–C–O–), etc. It has been determined by the thermogravimetric analysis that the hemicelluloses isolated from spruce wood are resistant to heating to temperatures of up to ~100 °C and, upon further heating, start destructing at an increasing rate. The antioxidant activity of the hemicelluloses has been examined using the compounds simulating the 2,2-diphenyl-2-picrylhydrazyl free radicals.
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- 2022
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15. Food Xanthan Polysaccharide Sulfation Process with Sulfamic Acid
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Aleksandr S. Kazachenko, Natalya Yu. Vasilieva, Valentina S. Borovkova, Olga Yu. Fetisova, Noureddine Issaoui, Yuriy N. Malyar, Evgeniy V. Elsuf’ev, Anton A. Karacharov, Andrey M. Skripnikov, Angelina V. Miroshnikova, Anna S. Kazachenko, Dmitry V. Zimonin, and Vladislav A. Ionin
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polysaccharides ,sulfation ,xanthan ,structure ,xanthan sulfate ,Chemical technology ,TP1-1185 - Abstract
Xanthan is an important polysaccharide with many beneficial properties. Sulfated xanthan derivatives have anticoagulant and antithrombotic activity. This work proposes a new method for the synthesis of xanthan sulfates using sulfamic acid. Various N-substituted ureas have been investigated as process activators. It was found that urea has the greatest activating ability. BBD of xanthan sulfation process with sulfamic acid in 1,4-dioxane has been carried out. It was shown that the optimal conditions for the sulfation of xanthan (13.1 wt% sulfur content) are: the amount of sulfating complex per 1 g of xanthan is 3.5 mmol, temperature 90 °C, duration 2.3 h. Sulfated xanthan with the maximum sulfur content was analyzed by physicochemical methods. Thus, in the FTIR spectrum of xanthan sulfate, in comparison with the initial xanthanum, absorption bands appear at 1247 cm−1, which corresponds to the vibrations of the sulfate group. It was shown by GPC chromatography that the starting xanthan gum has a bimodal molecular weight distribution of particles, including a high molecular weight fraction with Mw > 1000 kDa and an LMW fraction with Mw < 600 kDa. It was found that the Mw of sulfated xanthan gum has a lower value (~612 kDa) in comparison with the original xanthan gum, and a narrower molecular weight distribution and is characterized by lower PD values. It was shown by thermal analysis that the main decomposition of xanthan sulfate, in contrast to the initial xanthan, occurs in two stages. The DTG curve has two pronounced peaks, with maxima at 226 and 286 °C.
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- 2021
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16. Fractionation of Aspen Wood to Produce Microcrystalline, Microfibrillated and Nanofibrillated Celluloses, Xylan and Ethanollignin
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Taran, Boris N. Kuznetsov, Anna I. Chudina, Aleksandr S. Kazachenko, Olga Yu. Fetisova, Valentina S. Borovkova, Sergei A. Vorobyev, Anton A. Karacharov, Elena V. Gnidan, Elena V. Mazurova, Andrey M. Skripnikov, and Oxana P.
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aspen wood ,fractionation ,xylan ,ethanollignin ,microcrystalline ,microfibrillated and nanofibrillated celluloses - Abstract
A new method for extractive-catalytic fractionation of aspen wood to produce microcrystalline (MCC), microfibrillated (MFC), nanofibrilllated (NFC) celluloses, xylan, and ethanollignin is suggested in order to utilize all of the main components of wood biomass. Xylan is obtained with a yield of 10.2 wt.% via aqueous alkali extraction at room temperature. Ethanollignin was obtained with a yield of 11.2 wt.% via extraction with 60% ethanol from the xylan-free wood at 190 °C. The lignocellulose residue formed after the extraction of xylan and ethanollignin was subjected to catalytic peroxide delignification in the acetic acid-water medium at 100 °C in order to obtain microcrystalline cellulose. MCC is hydrolyzed with 56% sulfuric acid and treated with ultrasound to produce microfibrillated cellulose and nanofibrillated cellulose. The yields of MFC and NFC were 14.4 and 19.0 wt.%, respectively. The average hydrodynamic diameter of NFC particles was 36.6 nm, the crystallinity index was 0.86, and the average zeta-potential was 41.5 mV. The composition and structure of xylan, ethanollignin, cellulose product, MCC, MFC, and NFC obtained from aspen wood were characterized using elemental and chemical analysis, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analyses, Gas chromatography (GC), Gel permeation-chromatography (GPC), Scanning electron microscopy (SEM), Atomic force microscopy (AFM), Dynamic light scattering (DLS), Thermal gravimetric analysis (TGA).
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- 2023
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17. Synthesis and Physicochemical Study of Xanthan Butyl Ether
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Valentine V. Sychev, Olga Yu. Fetisova, Aleksandr V. Antonov, Aleksandr S. Kazachenko, and Galina N. Bondarenko
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chemistry.chemical_compound ,Chemistry ,General Chemical Engineering ,Organic chemistry ,Ether ,General Chemistry - Abstract
Xanthan is an important polysaccharide widely used in many industrial fields. It is produced by the bacteria Xanthomonascampestris. Chemical modification of xanthan can open up new horizons for its use. In this work, xanthan butyl ester was obtained for the first time by the interaction of xanthan and bromobutane using sodium hydroxide as a catalyst. The composition and structure of the obtained new xanthan derivative was studied by elemental analysis, IR spectroscopy, X-ray phase analysis, scanning electron microscopy and thermal analysis. The introduction of a butyl group into the xanthan molecule was proved by elemental analysis and IR spectroscopy by the appearance of corresponding bands. It was shown by X-ray phase analysis that xanthan butyl ether has a more X-ray amorphous structure in comparison with the original xanthan. It was shown by scanning electron microscopy that xanthan butyl ether powder consists of particles of a larger size and a layered structure in comparison with the original xanthan. It has been shown by thermal analysis that xanthan butyl ether is less thermostable than the starting xanthan
- Published
- 2021
18. Isolation and sulfation of galactoglucomannan from larch wood (Larix sibirica)
- Author
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Olga Yu. Fetisova, Svetlana A. Kuznetsova, Natalya Yu. Vasilyeva, Irina G. Sudakova, Aleksandr S. Kazachenko, Anna I. Chudina, Yuriy N. Malyar, Valentina S. Borovkova, and Aleksandr V. Antonov
- Subjects
040101 forestry ,0106 biological sciences ,Scanning electron microscope ,Forestry ,04 agricultural and veterinary sciences ,Plant Science ,01 natural sciences ,Endothermic process ,Industrial and Manufacturing Engineering ,Gel permeation chromatography ,chemistry.chemical_compound ,Sulfation ,chemistry ,010608 biotechnology ,Sulfamic acid ,0401 agriculture, forestry, and fisheries ,General Materials Science ,Fourier transform infrared spectroscopy ,Galactoglucomannan ,Thermal analysis ,Nuclear chemistry - Abstract
The synthesis of galactoglucomannan sulfates using a sulfamic acid/urea mixture in 1,4-dioxane was studied for the first time. The effect of the galactoglucomannan sulfation time and temperature on the sulfur content in the galactoglucomannan sulfates was investigated. The introduction of sulfate groups into the galactoglucomannan structure was confirmed by the elemental analysis and Fourier transform infrared spectroscopy. The initial and sulfated galactoglucomannans were identified by X-ray diffraction, electron microscopy, and gel permeation chromatography. The thermal analysis has shown that sulfated galactoglucomannan, after the endothermic peak related to the moisture removal, yields a pronounced high-intensity exothermic peak with a maximum at 216 °C, and above 230 °C, the heat absorption effect (endothermic peak) characteristic of decomposition of the parent substance in the range of 230–335 °C is observed. According to the scanning electron microscopy data, the initial galactoglucomannan consists of irregular asymmetric particles with an average size from 400 to 900 µm, and the sulfated galactoglucomannan ammonium salt consists of particles 200–500 µm in size with different shapes. It was shown by gel permeation chromatography that, after the sulfation process, the main galactoglucomannan peak shifts toward higher molecular masses (from 24 to 26 kDa).
- Published
- 2021
19. Fabrication of Extremely Concentrated Silver Hydrosols without Additional Stabilizers
- Author
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Alexander Romanchenko, Olga Yu. Fetisova, Mikhail N. Volochaev, Alexander S. Kazachenko, Yuri Mikhlin, Sergey Vorobyev, and Maxim Likhatski
- Subjects
Fabrication ,Materials science ,Renewable Energy, Sustainability and the Environment ,General Chemical Engineering ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Environmentally friendly ,Silver nanoparticle ,0104 chemical sciences ,Dynamic light scattering ,Environmental Chemistry ,0210 nano-technology - Abstract
Applications of silver nanoparticles (Ag NPs) in modern technologies require environmentally friendly methods of large-scale production of the nanoparticles with controlled morphology and surface s...
- Published
- 2020
20. New reactions of betulin with sulfamic acid and ammonium sulfamate in the presence of solid catalysts
- Author
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Aleksandr S. Kazachenko, Natalya Yu. Vasilieva, Olga Yu. Fetisova, Valentine V. Sychev, Evgeniy V. Elsuf’ev, Yuriy N. Malyar, Noureddine Issaoui, Angelina V. Miroshnikova, Valentina S. Borovkova, Anna S. Kazachenko, Yaroslava D. Berezhnaya, Andrey M. Skripnikov, Dmitry V. Zimonin, and Vladislav A. Ionin
- Subjects
Renewable Energy, Sustainability and the Environment - Published
- 2022
21. «Green» synthesis and characterization of galactomannan sulfates obtained using sulfamic acid
- Author
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Anton Karacharov, Olga Yu. Fetisova, Galina N. Bondarenko, Irina V. Korolkova, G. P. Skvortsova, Yuriy N. Malyar, Aleksandr S. Kazachenko, Natalya Yu. Vasilyeva, and Aleksandr V. Antonov
- Subjects
Exothermic reaction ,Renewable Energy, Sustainability and the Environment ,Scanning electron microscope ,020209 energy ,Analytical chemistry ,Infrared spectroscopy ,02 engineering and technology ,010501 environmental sciences ,bacterial infections and mycoses ,01 natural sciences ,Endothermic process ,respiratory tract diseases ,carbohydrates (lipids) ,Gel permeation chromatography ,chemistry.chemical_compound ,Galactomannan ,chemistry ,0202 electrical engineering, electronic engineering, information engineering ,Sulfamic acid ,skin and connective tissue diseases ,Thermal analysis ,0105 earth and related environmental sciences - Abstract
The “green” synthesis of galactomannan sulfates using a sulfamic acid–urea mixture has been studied for the first time. The effect of the time and temperature of the galactomannan sulfation process on the degree of substitution of galactomannan sulfates has been investigated. It is shown that, at a temperature of 70 °C with an increase in the process time up to 120 min, the degree of substitution increases up to 0.70. An increase in the process temperature up to 80 °C leads to the production of galactomannan sulfates with a degree of substitution of 1.67. With a further increase in the process temperature to 90 °C, the galactomannan structure is partially destructed, and the degree of substitution decreases. Embedding of the sulfate groups into the galactomannan structure has been confirmed by elemental analysis and Fourier-transform infrared spectroscopy. In addition, the initial and sulfated galactomannans have been characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and gel permeation chromatography. The thermal analysis shows that the initial galactomannan exhibits endothermic peaks at 254 and 294 °C and an exothermic peak at 315 °C, while sulfated galactomannan exhibits endothermic peaks at 209 and 275 °C and an exothermic peak at 281 °C. Using atomic force microscopy, it has been shown that the sulfated galactomannan film consists of spherical particles with an average diameter of 200–300 nm; according to the phase contrast data, it has the uniform composition without extraneous impurities.
- Published
- 2020
22. Molecular Characteristics and Antioxidant Activity of Spruce (
- Author
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Valentina S, Borovkova, Yuriy N, Malyar, Irina G, Sudakova, Anna I, Chudina, Andrey M, Skripnikov, Olga Yu, Fetisova, Alexander S, Kazachenko, Angelina V, Miroshnikova, Dmitriy V, Zimonin, Vladislav A, Ionin, Anastasia A, Seliverstova, Ekaterina D, Samoylova, and Noureddine, Issaoui
- Subjects
delignification ,Hot Temperature ,Xylose ,gel permeation chromatography ,wood polysaccharides ,antioxidant activity ,hemicellulose ,molecular weight distribution ,Lignin ,Antioxidants ,Catalysis ,Article ,Polysaccharides ,Picea - Abstract
Spruce (Picea abies) wood hemicelluloses have been obtained by the noncatalytic and catalytic oxidative delignification in the acetic acid-water-hydrogen peroxide medium in a processing time of 3–4 h and temperatures of 90–100 °C. In the catalytic process, the H2SO4, MnSO4, TiO2, and (NH4)6Mo7O24 catalysts have been used. A polysaccharide yield of up to 11.7 wt% has been found. The hemicellulose composition and structure have been studied by a complex of physicochemical methods, including gas and gel permeation chromatography, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The galactose:mannose:glucose:arabinose:xylose monomeric units in a ratio of 5:3:2:1:1 have been identified in the hemicelluloses by gas chromatography. Using gel permeation chromatography, the weight average molar mass Mw of hemicelluloses has been found to attain 47,654 g/mol in noncatalytic delignification and up to 42,793 g/mol in catalytic delignification. Based on the same technique, a method for determining the α and k parameters of the Mark–Kuhn–Houwink equation for hemicelluloses has been developed; it has been established that these parameters change between 0.33–1.01 and 1.57–472.17, respectively, depending on the catalyst concentration and process temperature and time. Moreover, the FTIR spectra of the hemicellulose samples contain all the bands characteristic of heteropolysaccharides, specifically, 1069 cm−1 (C–O–C and C–O–H), 1738 cm−1 (ester C=O), 1375 cm−1 (–C–CH3), 1243 cm−1 (–C–O–), etc. It has been determined by the thermogravimetric analysis that the hemicelluloses isolated from spruce wood are resistant to heating to temperatures of up to ~100 °C and, upon further heating, start destructing at an increasing rate. The antioxidant activity of the hemicelluloses has been examined using the compounds simulating the 2,2-diphenyl-2-picrylhydrazyl free radicals.
- Published
- 2021
23. Food Xanthan Polysaccharide Sulfation Process with Sulfamic Acid
- Author
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Angelina V. Miroshnikova, Valentina S. Borovkova, Aleksandr S. Kazachenko, Anton Karacharov, Evgeniy V. Elsuf’ev, Yuriy N. Malyar, Noureddine Issaoui, Dmitry V. Zimonin, Vladislav A. Ionin, Olga Yu. Fetisova, Andrey M. Skripnikov, A S Kazachenko, and Natalya Yu. Vasilieva
- Subjects
Health (social science) ,polysaccharides ,Plant Science ,TP1-1185 ,Polysaccharide ,Health Professions (miscellaneous) ,Microbiology ,Article ,Gel permeation chromatography ,chemistry.chemical_compound ,Sulfation ,xanthan ,Sulfamic acid ,medicine ,structure ,Sulfate ,chemistry.chemical_classification ,Chemical technology ,sulfation ,xanthan sulfate ,chemistry ,Urea ,Molar mass distribution ,Xanthan gum ,Food Science ,medicine.drug ,Nuclear chemistry - Abstract
Xanthan is an important polysaccharide with many beneficial properties. Sulfated xanthan derivatives have anticoagulant and antithrombotic activity. This work proposes a new method for the synthesis of xanthan sulfates using sulfamic acid. Various N-substituted ureas have been investigated as process activators. It was found that urea has the greatest activating ability. BBD of xanthan sulfation process with sulfamic acid in 1,4-dioxane has been carried out. It was shown that the optimal conditions for the sulfation of xanthan (13.1 wt% sulfur content) are: the amount of sulfating complex per 1 g of xanthan is 3.5 mmol, temperature 90 °C, duration 2.3 h. Sulfated xanthan with the maximum sulfur content was analyzed by physicochemical methods. Thus, in the FTIR spectrum of xanthan sulfate, in comparison with the initial xanthanum, absorption bands appear at 1247 cm−1, which corresponds to the vibrations of the sulfate group. It was shown by GPC chromatography that the starting xanthan gum has a bimodal molecular weight distribution of particles, including a high molecular weight fraction with Mw >, 1000 kDa and an LMW fraction with Mw <, 600 kDa. It was found that the Mw of sulfated xanthan gum has a lower value (~612 kDa) in comparison with the original xanthan gum, and a narrower molecular weight distribution and is characterized by lower PD values. It was shown by thermal analysis that the main decomposition of xanthan sulfate, in contrast to the initial xanthan, occurs in two stages. The DTG curve has two pronounced peaks, with maxima at 226 and 286 °C.
- Published
- 2021
24. Physicochemical characteristics of polysaccharides from catalytic and noncatalytic acetic acid-peroxide delignification of larch wood
- Author
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Andrey M. Skripnikov, Olga Yu. Fetisova, Aleksandr S. Kazachenko, Alexander A. Kondrasenko, Irina G. Sudakova, Anna I. Chudina, Valentina S. Borovkova, Yuriy N. Malyar, Elena V. Mazurova, and Ivan P. Ivanov
- Subjects
Gel permeation chromatography ,chemistry.chemical_classification ,chemistry.chemical_compound ,Thermogravimetric analysis ,Acetic acid ,Adsorption ,chemistry ,Renewable Energy, Sustainability and the Environment ,Gas chromatography ,Polysaccharide ,Peroxide ,Catalysis ,Nuclear chemistry - Abstract
The composition and physicochemical characteristics of polysaccharides extracted from spent liquors of catalytic and noncatalytic delignification of larch wood in the acetic acid-hydrogen peroxide medium were studied. The following were used as catalysts: (NH4)6Mo7O24, MnSO4, TiO2, and ZnSO4. The structure of polysaccharides was identified by FTIR and NMR spectroscopy. Their composition was established using gas chromatography, and the physicochemical characteristics were studied using gel permeation chromatography, scanning electron microscopy, thermogravimetric analysis, gas adsorption, and elemental analysis. It was shown that in the process of oxidative delignification, a significant amount of hemicelluloses and arabinogalactan passes into the spent liquor. The yield of polysaccharides was up to 16.9 wt%. Polysaccharides had a weight-average molecular weight of up to 22.9 kDa and a narrow molecular weight distribution.
- Published
- 2021
25. Features of Steam Activation in Fluidized Bed Reactor the Larch Bark and Solid Residues of Its from Extraction Processing
- Author
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Nikolai V. Chesnokov, Alexey V. Rudkovskiy, and Olga Yu. Fetisova
- Subjects
Materials science ,biology ,Fluidized bed ,General Chemical Engineering ,visual_art ,Extraction (chemistry) ,visual_art.visual_art_medium ,Bark ,General Chemistry ,Larch ,Pulp and paper industry ,biology.organism_classification ,Steam activation - Published
- 2016
26. Structural and current-voltage characteristics of carbon materials obtained during carbonization of fir and aspen barks
- Author
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S. I. Tsyganova, Olga Yu. Fetisova, Galina V. Bondarenko, Elena V. Mazurova, and G. P. Skvortsova
- Subjects
Materials science ,Calcium hydroxide ,Renewable Energy, Sustainability and the Environment ,Magnesium ,Carbonization ,020209 energy ,Potassium ,chemistry.chemical_element ,Forestry ,02 engineering and technology ,complex mixtures ,Metal ,chemistry.chemical_compound ,chemistry ,Amorphous carbon ,Chemical engineering ,visual_art ,0202 electrical engineering, electronic engineering, information engineering ,visual_art.visual_art_medium ,Bark ,Waste Management and Disposal ,Agronomy and Crop Science ,Carbon - Abstract
The purpose of this study is to investigate the composition and structural changes of aspen and fir barks for thermochemical transformation and to determine the electrical capacity of the obtained carbonized barks. Significant differences of the structural and current-voltage characteristics of carbonized barks were revealed. The carbonized product from aspen bark mainly consists of the amorphous carbon and the crystalline phase of calcium hydroxide; the product from fir bark consists of amorphous-crystalline carbon. Cyclic voltammetric curves indicate the formation of electric double layer in the obtained carbon products and imply their potential use for energy accumulation and storage. Passing of Faraday processes and the pseudo-capacity are revealed in aspen carbonized at 800 °C. These features are absent in the carbon product obtained from fir bark. The apparent specific capacity of carbonized aspen bark (450 Fg-1) is higher than carbonized fir bark (83 F*g−1).The probable reason is the effect of oxides of metal such as calcium, magnesium, potassium and sodium, which content is two times higher in the aspen bark compared to the fir bark. The apparent specific capacity as function of the potential sweep speed is different for aspen and fir barks. This difference can be caused by the inhomogeneous distribution of mineral substances in the carbon matrix.
- Published
- 2020
27. Increasing the Strength of Carbon Sorbents from the Extracted Larch Bark by Using Additives of Oil Bituminen
- Author
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Alexey V. Rudkovskiy, Nikolai V. Chesnokov, and Olga Yu. Fetisova
- Subjects
chemistry ,biology ,General Chemical Engineering ,visual_art ,visual_art.visual_art_medium ,chemistry.chemical_element ,Bark ,General Chemistry ,Larch ,biology.organism_classification ,Pulp and paper industry ,Carbon - Published
- 2016
28. Preparation and characterization of colloidal copper xanthate nanoparticles
- Author
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S. V. Saikova, Olga Yu. Fetisova, Svetlana G. Kozlova, Sergey M. Zharkov, Sergey Vorobyev, Yuri Mikhlin, and Yevgeny Tomashevich
- Subjects
Inorganic chemistry ,Thermal decomposition ,chemistry.chemical_element ,Nanoparticle ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Copper ,Catalysis ,0104 chemical sciences ,Copper sulfide ,chemistry.chemical_compound ,Dynamic light scattering ,chemistry ,Materials Chemistry ,Zeta potential ,Xanthate ,Fourier transform infrared spectroscopy ,0210 nano-technology - Abstract
Despite the important role of metal xanthates in a number of industrial processes and emerging applications, no attempts have been made to prepare the metal xanthate nanoparticles and to study colloidal solutions of insoluble heavy metal xanthates. Here, we examined the formation of colloidal copper xanthate particles during the reactions of aqueous solutions of cupric sulfate and various potassium xanthates, which occur in flotation and water treatment slurries and can be used to manufacture nanoparticles for materials science (e.g., as precursors for copper sulfide nanoparticles and biomedicine). The products were characterized using UV-vis absorption, dynamic light scattering, zeta potential measurements, transmission electron microscopy (TEM), electron diffraction, Fourier transform infrared spectroscopy, thermogravimetry, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy (XANES). Colloidal copper xanthates with compositions of ROCSSCu (R = ethyl, isopropyl, butyl, isobutyl, and amyl groups), disordered structures and average diameters of 20–80 nm easily formed and aggregated and were stable for at least several hours, especially if excessive xanthate was used. The hydrodynamic diameters of the nanoparticles were smaller at lower temperatures. Dixanthogens, which were produced in the reactions along with ROCSSCu, seemed to promote nanoparticle aggregation and precipitated with the copper xanthate, affecting their thermal decomposition. The TEM micrographs and S K- and Cu K-edge XANES spectra revealed core/shell particle morphologies, likely with Cu(I) bonded to four S atoms in the core and reduced copper coordination in the shell.
- Published
- 2016
Catalog
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