O. Zolotarenko, A. Zolotarenko, E. Rudakova, N. Akhanova, M. Ualkhanova, D. V. Schur, M. Gabdullin, T. Myronenko, A. Zolotarenko, M. Chymbai, I. Zagorulko, O. Havryliuk
The goal of the research work was the pyrolytic synthesis of straight and spiral carbon nanotubes of approximately the same diameter, as well as their comprehensive analysis. To solve the given problem, a new installation for the pyrolytic synthesis of carbon nanostructures (CNS) with a fusion reactor, which for each fusion process can have its own angle relative to the classical horizontal position of the reactor axis. This reactor made it possible to develop a method for obtaining conglomerates of spiral-shaped multi-walled carbon nanotubes with a diameter of 15–60 nm and to synthesize straight multi-walled carbon nanotubes with a diameter of 5 to 60 nm. The research of pyrolytic synthesis of carbon nanostructures in a vertical reactor allows to work out the technology of purposeful synthesis of nanotubes that have a spiral shape with a certain diameter and pitch of the turn. As part of the work, a new mechanism for the formation of spiral multi-walled carbon nanotubes is also considered and proposed, which is important for their further industrial synthesis and their use in related composites. A scheme is proposed of conditions for the synthesis of carbon nanostructures by the pyrolytic method. Thermal analysis was carried out in the work, which recorded the presence of two different structures with low thermal stability (probably amorphous carbon and higher hydrocarbons). When using scanning and transmission electron microscopy, the formation of spiral nanofibers with a diameter of 15–60 nm in the vertical position of the reactor was recorded, and in the horizontal position of the reactor, the formation of straight and slightly curved MWCTs with a diameter of nanofibers from 5 to 60 nm was found. Raman spectroscopy confirms the presence of multi-layered carbon tubular formation, i.e. MWCT, in both synthesis products.
{"title":"Features of the synthesis of straight and spiral carbon nanotubes by the pyrolytic method","authors":"O. Zolotarenko, A. Zolotarenko, E. Rudakova, N. Akhanova, M. Ualkhanova, D. V. Schur, M. Gabdullin, T. Myronenko, A. Zolotarenko, M. Chymbai, I. Zagorulko, O. Havryliuk","doi":"10.15407/hftp14.02.191","DOIUrl":"https://doi.org/10.15407/hftp14.02.191","url":null,"abstract":"The goal of the research work was the pyrolytic synthesis of straight and spiral carbon nanotubes of approximately the same diameter, as well as their comprehensive analysis. To solve the given problem, a new installation for the pyrolytic synthesis of carbon nanostructures (CNS) with a fusion reactor, which for each fusion process can have its own angle relative to the classical horizontal position of the reactor axis. This reactor made it possible to develop a method for obtaining conglomerates of spiral-shaped multi-walled carbon nanotubes with a diameter of 15–60 nm and to synthesize straight multi-walled carbon nanotubes with a diameter of 5 to 60 nm. The research of pyrolytic synthesis of carbon nanostructures in a vertical reactor allows to work out the technology of purposeful synthesis of nanotubes that have a spiral shape with a certain diameter and pitch of the turn. As part of the work, a new mechanism for the formation of spiral multi-walled carbon nanotubes is also considered and proposed, which is important for their further industrial synthesis and their use in related composites. A scheme is proposed of conditions for the synthesis of carbon nanostructures by the pyrolytic method. Thermal analysis was carried out in the work, which recorded the presence of two different structures with low thermal stability (probably amorphous carbon and higher hydrocarbons). When using scanning and transmission electron microscopy, the formation of spiral nanofibers with a diameter of 15–60 nm in the vertical position of the reactor was recorded, and in the horizontal position of the reactor, the formation of straight and slightly curved MWCTs with a diameter of nanofibers from 5 to 60 nm was found. Raman spectroscopy confirms the presence of multi-layered carbon tubular formation, i.e. MWCT, in both synthesis products.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"150 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130244118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Hryhoruk, V. Oliynyk, V. Zagorodniy, G. Lisachuk, R. Kryvobok, V. Voloshchuk, M. S. Maystat, O. Lapuzina
Nowadays, people are constantly under the influence of electromagnetic radiation, which can cause health deterioration. The creation of ceramic materials that protect biological and technical objects from the negative effects of electromagnetic radiation is relevant for Ukraine and the world. The purpose of the study is to create composite ceramics with the addition of graphite and conduct experimental studies of the electrophysical properties of such material samples in the frequency range of 26–37.5 GHz. The results of experimental studies of the developed ceramics based on facing tiles with an electrically conductive additive of 10, 20, and 30 % wt. of graphite. To determine the parameters of the interaction of electromagnetic radiation with the samples, the modernized standard equipment – P2-65 microwave standing wave coefficient and attenuation meter, was used. The phase composition of the material was determined using the method of X-ray phase analysis using a DRON-3M diffractometer with CuKα radiation with a nickel filter. The developed composite ceramic materials meet the basic requirements for the operation of similar materials and can be used to weaken the high-frequency electromagnetic field inside premises located in the areas of radio radiation action, and for environmental purposes to reduce the intensity of the electromagnetic field outside the premises where sources of radio radiation are present. Thus, the developed composite ceramics have characteristics that allow them to be used in construction and in electronic devices for the purpose of effective shielding of harmful radio radiation, and the developed ceramics, according to the classification, can be classified as radio-absorbing.
{"title":"Study of the electrodynamic properties of composite ceramics","authors":"V. Hryhoruk, V. Oliynyk, V. Zagorodniy, G. Lisachuk, R. Kryvobok, V. Voloshchuk, M. S. Maystat, O. Lapuzina","doi":"10.15407/hftp14.02.249","DOIUrl":"https://doi.org/10.15407/hftp14.02.249","url":null,"abstract":"Nowadays, people are constantly under the influence of electromagnetic radiation, which can cause health deterioration. The creation of ceramic materials that protect biological and technical objects from the negative effects of electromagnetic radiation is relevant for Ukraine and the world. The purpose of the study is to create composite ceramics with the addition of graphite and conduct experimental studies of the electrophysical properties of such material samples in the frequency range of 26–37.5 GHz. The results of experimental studies of the developed ceramics based on facing tiles with an electrically conductive additive of 10, 20, and 30 % wt. of graphite. To determine the parameters of the interaction of electromagnetic radiation with the samples, the modernized standard equipment – P2-65 microwave standing wave coefficient and attenuation meter, was used. The phase composition of the material was determined using the method of X-ray phase analysis using a DRON-3M diffractometer with CuKα radiation with a nickel filter. The developed composite ceramic materials meet the basic requirements for the operation of similar materials and can be used to weaken the high-frequency electromagnetic field inside premises located in the areas of radio radiation action, and for environmental purposes to reduce the intensity of the electromagnetic field outside the premises where sources of radio radiation are present. Thus, the developed composite ceramics have characteristics that allow them to be used in construction and in electronic devices for the purpose of effective shielding of harmful radio radiation, and the developed ceramics, according to the classification, can be classified as radio-absorbing.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"428 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122875093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The main task and relevance of this work are to develop the most effective sorbents for cleaning oil pollution or accidental oil spills. A generalized criterion for evaluating the effectiveness of a sorbent is the local availability and fast renewability of raw materials for biochar. The features of obtaining biochar from cellulose-containing plant raw materials of corn cobs are described. The effect was studied of the pyrolysis conditions of the selected plant material on the physicochemical properties of biochar, which are responsible for the intermolecular interaction of the sorbent with the adsorbed substance and for immobilization and viability of oil degrading bacteria, which indicates the possibility to control the properties of oil destructive sorbent at the production stage. The optimal mode of carbonization of such raw materials has been worked out to obtain a sorbent with porosity and chemical compatibility with oil-degrading bacteria. Cultural cultivation for immobilization of oil-degrading bacteria was carried out in a nutrient medium and a concentrate was prepared. It is shown that biochar with oil-oxidizing microorganisms fixed on its surface has significant sorption and destructive properties.
{"title":"Chemical-physical features of the biochar-based oil-destructive sorbent","authors":"A. Khokhlov","doi":"10.15407/hftp14.02.255","DOIUrl":"https://doi.org/10.15407/hftp14.02.255","url":null,"abstract":"The main task and relevance of this work are to develop the most effective sorbents for cleaning oil pollution or accidental oil spills. A generalized criterion for evaluating the effectiveness of a sorbent is the local availability and fast renewability of raw materials for biochar. The features of obtaining biochar from cellulose-containing plant raw materials of corn cobs are described. The effect was studied of the pyrolysis conditions of the selected plant material on the physicochemical properties of biochar, which are responsible for the intermolecular interaction of the sorbent with the adsorbed substance and for immobilization and viability of oil degrading bacteria, which indicates the possibility to control the properties of oil destructive sorbent at the production stage. The optimal mode of carbonization of such raw materials has been worked out to obtain a sorbent with porosity and chemical compatibility with oil-degrading bacteria. Cultural cultivation for immobilization of oil-degrading bacteria was carried out in a nutrient medium and a concentrate was prepared. It is shown that biochar with oil-oxidizing microorganisms fixed on its surface has significant sorption and destructive properties.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126364033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Makhno, O. M. Lisova, G. M. Gunya, P. Gorbyk, M. Kartel
Nanocomposites containing components with semiconductor, ferroelectric, and ferromagnetic properties have attracted considerable attention of specialists due to the range of possible applications, including catalysis and electrocatalysis, electrode materials for solar and fuel cells, capacitors, electrical and biosensors, anti-corrosion coatings and much more. In recent years, both fundamental and applied interest in this direction of research is due to the possibility of creating a new type of controlled microwave devices and tools. The aim of the work is to develop methods for the synthesis of nanostructured NiCo composites based on BaTiO3 and TiO2, as well as to find the differences and regularities of their physicochemical properties. Two series of samples with different content of NiCo nanoparticles based on titanium oxide (TiO2) and barium titanate (BaTiO3) were obtained. NiCo particles were obtained by the method of chemical precipitation of nickel and cobalt carbonates in equal parts from a hydrazine hydrate solution at the temperature of 350 K. The results of X-ray phase analysis indicate the chemical purity of the obtained samples. The values of ε′, ε″ at a frequency of 9 GHz for the NiCo/BaTiO3 system are twice as high compared to NiCo/TiO2 for the corresponding values of the NiCo content, which is due to the higher values of ε′, ε″ of the initial barium titanate. Electrical conductivity of NiCo/BaTiO3 system changes by six orders of magnitude, which indicates the formation of a continuous percolation cluster of metal particles on the surface of dielectric BaTiO3 particles. The composites are heat-resistant up to 630K, as shown by the method of thermogravimetry and pronounced magnetic properties. The program for calculating frequency dependences of reflection and absorption coefficients in a complex form has been developed. EMF absorption for composites from the radiation frequency and the position of the minima of these characteristics, which agree satisfactorily with the experiment. The obtained composites can be promising components for obtaining composite systems and paints for protection against electromagnetic radiation.
{"title":"Synthesis and electrophysical properties of nanostructured composites NіCо/BaTiO3 and NiCo/TiO2","authors":"S. Makhno, O. M. Lisova, G. M. Gunya, P. Gorbyk, M. Kartel","doi":"10.15407/hftp14.02.173","DOIUrl":"https://doi.org/10.15407/hftp14.02.173","url":null,"abstract":"Nanocomposites containing components with semiconductor, ferroelectric, and ferromagnetic properties have attracted considerable attention of specialists due to the range of possible applications, including catalysis and electrocatalysis, electrode materials for solar and fuel cells, capacitors, electrical and biosensors, anti-corrosion coatings and much more. In recent years, both fundamental and applied interest in this direction of research is due to the possibility of creating a new type of controlled microwave devices and tools. The aim of the work is to develop methods for the synthesis of nanostructured NiCo composites based on BaTiO3 and TiO2, as well as to find the differences and regularities of their physicochemical properties. Two series of samples with different content of NiCo nanoparticles based on titanium oxide (TiO2) and barium titanate (BaTiO3) were obtained. NiCo particles were obtained by the method of chemical precipitation of nickel and cobalt carbonates in equal parts from a hydrazine hydrate solution at the temperature of 350 K. The results of X-ray phase analysis indicate the chemical purity of the obtained samples. The values of ε′, ε″ at a frequency of 9 GHz for the NiCo/BaTiO3 system are twice as high compared to NiCo/TiO2 for the corresponding values of the NiCo content, which is due to the higher values of ε′, ε″ of the initial barium titanate. Electrical conductivity of NiCo/BaTiO3 system changes by six orders of magnitude, which indicates the formation of a continuous percolation cluster of metal particles on the surface of dielectric BaTiO3 particles. The composites are heat-resistant up to 630K, as shown by the method of thermogravimetry and pronounced magnetic properties. The program for calculating frequency dependences of reflection and absorption coefficients in a complex form has been developed. EMF absorption for composites from the radiation frequency and the position of the minima of these characteristics, which agree satisfactorily with the experiment. The obtained composites can be promising components for obtaining composite systems and paints for protection against electromagnetic radiation.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127264422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study determined the corrosion inhibition levels of benzimidazole (BIA), 1-hydroxybenzotriazole (HBT), methylbenzimidazole (MBI) and 4-phenylimidazole (PIZ). By using simulation, it was possible to have a complete relationship with the experimental work because the results were completely consistent. Density functional theory (DFT) and Monte Carlo simulations were used to calculate several quantum chemical parameters. The molecules are simulated using quantum chemical calculations with Gaussian09 software. Fundamental factors determining the corrosion order of molecules are the highest-energy occupied and lowest-energy unoccupied molecular orbitals (HOMO and LUMO), frontier molecular orbital energy, back donating energy, electrophilicity, nucleophilicity, energy gap ∆E, absolute electronegativity (χ), softness, the number of electrons (∆N) transferred from inhibitors to iron, the dipole moment (μ), the global hardness (η) and the total energy.
{"title":"Quantum computations and density functional theory on corrosion inhibition efficiency of BIA, HBT, MBI and PIZ compounds","authors":"D. Mamand, H. Qadr","doi":"10.15407/hftp14.02.159","DOIUrl":"https://doi.org/10.15407/hftp14.02.159","url":null,"abstract":"This study determined the corrosion inhibition levels of benzimidazole (BIA), 1-hydroxybenzotriazole (HBT), methylbenzimidazole (MBI) and 4-phenylimidazole (PIZ). By using simulation, it was possible to have a complete relationship with the experimental work because the results were completely consistent. Density functional theory (DFT) and Monte Carlo simulations were used to calculate several quantum chemical parameters. The molecules are simulated using quantum chemical calculations with Gaussian09 software. Fundamental factors determining the corrosion order of molecules are the highest-energy occupied and lowest-energy unoccupied molecular orbitals (HOMO and LUMO), frontier molecular orbital energy, back donating energy, electrophilicity, nucleophilicity, energy gap ∆E, absolute electronegativity (χ), softness, the number of electrons (∆N) transferred from inhibitors to iron, the dipole moment (μ), the global hardness (η) and the total energy.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126875497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Ilnytska, O. B. Loginova, S. Starik, S. O. Lisovenko, G. Bazaliy, N. N. Tsyba
It has been found that ultrasonic treatment of diamond nanopowders contributes to surface cleaning due to the removal of non-diamond carbon and impurities from the surface boundary of nanodiamond grains (from 0.4 and 0.32 % for ASUD-99 and 0.67 and 0.55 % for ASUD 75, respectively). It does not affect the total sorption volume and the values of the specific surface of the studied samples do not change, but it changes the composition of groups on the surface of diamond nanoparticles, which affect its hydrophilicity. In the samples of АSUD-75 after ultrasonic treatment, a redistribution of the ratio of the intensities of valence vibrations of С=О bonds in the lactone (anhydride) group (1742 cm–1) and the quinone (carboxyl) group (1683 cm–1) is observed, which indicates the decay of the lactone ring and its transformation into carbonyl and carboxyl groups. All samples of АSUD-99 have a hydroxyl group O-H (3400 cm−1), which does not change significantly under the influence of ultrasound. This explains the noticeable change in agglomeration for ASUD-75 in contrast to ASUD 99.
{"title":"Effects of ultrasonic treatment on aqueous suspensions of diamond nanopowders","authors":"G. Ilnytska, O. B. Loginova, S. Starik, S. O. Lisovenko, G. Bazaliy, N. N. Tsyba","doi":"10.15407/hftp14.02.223","DOIUrl":"https://doi.org/10.15407/hftp14.02.223","url":null,"abstract":"It has been found that ultrasonic treatment of diamond nanopowders contributes to surface cleaning due to the removal of non-diamond carbon and impurities from the surface boundary of nanodiamond grains (from 0.4 and 0.32 % for ASUD-99 and 0.67 and 0.55 % for ASUD 75, respectively). It does not affect the total sorption volume and the values of the specific surface of the studied samples do not change, but it changes the composition of groups on the surface of diamond nanoparticles, which affect its hydrophilicity. In the samples of АSUD-75 after ultrasonic treatment, a redistribution of the ratio of the intensities of valence vibrations of С=О bonds in the lactone (anhydride) group (1742 cm–1) and the quinone (carboxyl) group (1683 cm–1) is observed, which indicates the decay of the lactone ring and its transformation into carbonyl and carboxyl groups. All samples of АSUD-99 have a hydroxyl group O-H (3400 cm−1), which does not change significantly under the influence of ultrasound. This explains the noticeable change in agglomeration for ASUD-75 in contrast to ASUD 99.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114859996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hybrid carbons/metals/metal (metalloid) oxides composites could be effective adsorbents for low– and high–molecular weight compounds, polar and nonpolar, gaseous and liquid. The presence of metal nanocrystallites and carbon nanostructures could provide catalytic properties in redox reactions. For more effective use of hybrid composites, their morphological, structural, textural, and adsorption characteristics should be appropriate for target applications and, therefore, well controlled. Therefore, the aim of this study was to synthesize carbon/metal/silica nanostructured composites with varied content of metal (Ni) to control the mentioned characteristics. Precipitated silica Sipernat 50 was selected as a substrate. Potato starch was used as a carbon precursor. Nickel nitrate (Ni(NO3)2·6H2O) of varied amounts was used as a precursor of Ni nanoparticles reduced upon the starch carbonization. After the starch carbonization and Ni reduction, a set of C/Ni/silica samples was studied using atomic force microscopy, X–ray diffraction, X–ray fluorescence spectroscopy, nitrogen and p-nitrophenol adsorption, thermogravimetry, and Raman spectroscopy. The presence of nickel phase results in the formation of smaller but denser packed char nanoparticles. Estimation of possible contribution of pores accessible for nitrogen molecules in silica globules and outer surface of carbon/Ni particles suggests that the carbon phase is porous that provides a significant part of the specific surface area of the composites. Amorphous silica and char phases are characterized by the presence of certain nuclei of radius (R) < 1 nm and 2 nm < R < 10 nm estimated from the XRD patterns using full peak profile analysis with a self–consistent regularization procedure. Ni crystallites are of several sizes, since particle size distributions include two–three peaks in the range of 3–13 nm in radius. The Raman spectra show that the main changes with increasing Ni content are characteristic to sp3 carbon structures (D line) in contrast to the sp2 structures (G line). The pore size distributions (both differential and incremental) demonstrate complex changes in a broad size range due to increasing Ni content in composites. As a whole, changes in the Ni content in nanostructured C/Ni/silica composites allow one to control the morphological, structural, and textural characteristics of the whole materials.
{"title":"Nanostructured composites with precipitated silica – Ni crystallites coated by char with carbonized starch","authors":"V. Gun'ko, B. Charmas, J. Skubiszewska-Zięba","doi":"10.15407/hftp14.02.143","DOIUrl":"https://doi.org/10.15407/hftp14.02.143","url":null,"abstract":"Hybrid carbons/metals/metal (metalloid) oxides composites could be effective adsorbents for low– and high–molecular weight compounds, polar and nonpolar, gaseous and liquid. The presence of metal nanocrystallites and carbon nanostructures could provide catalytic properties in redox reactions. For more effective use of hybrid composites, their morphological, structural, textural, and adsorption characteristics should be appropriate for target applications and, therefore, well controlled. Therefore, the aim of this study was to synthesize carbon/metal/silica nanostructured composites with varied content of metal (Ni) to control the mentioned characteristics. Precipitated silica Sipernat 50 was selected as a substrate. Potato starch was used as a carbon precursor. Nickel nitrate (Ni(NO3)2·6H2O) of varied amounts was used as a precursor of Ni nanoparticles reduced upon the starch carbonization. After the starch carbonization and Ni reduction, a set of C/Ni/silica samples was studied using atomic force microscopy, X–ray diffraction, X–ray fluorescence spectroscopy, nitrogen and p-nitrophenol adsorption, thermogravimetry, and Raman spectroscopy. The presence of nickel phase results in the formation of smaller but denser packed char nanoparticles. Estimation of possible contribution of pores accessible for nitrogen molecules in silica globules and outer surface of carbon/Ni particles suggests that the carbon phase is porous that provides a significant part of the specific surface area of the composites. Amorphous silica and char phases are characterized by the presence of certain nuclei of radius (R) < 1 nm and 2 nm < R < 10 nm estimated from the XRD patterns using full peak profile analysis with a self–consistent regularization procedure. Ni crystallites are of several sizes, since particle size distributions include two–three peaks in the range of 3–13 nm in radius. The Raman spectra show that the main changes with increasing Ni content are characteristic to sp3 carbon structures (D line) in contrast to the sp2 structures (G line). The pore size distributions (both differential and incremental) demonstrate complex changes in a broad size range due to increasing Ni content in composites. As a whole, changes in the Ni content in nanostructured C/Ni/silica composites allow one to control the morphological, structural, and textural characteristics of the whole materials.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128166844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aromatic organic acids are among the common environmental pollutants that enter the water with washouts from agricultural lands, wastewater from chemical and pharmaceutical industries. Taking into account the high toxicity of aromatic substances, the important task of water purification is the removal of their trace amounts. This problem can be solved by using chemically modified inorganic materials, such as silicas, which have high mechanical, chemical, hydrolytic, and radiation stability. Therefore, they do not lose their sorption capacity during long-term use and do not pollute water with sorbent degradation products. The purpose of this work is the synthesis of a sorption-active material for removal of toxic aromatic acids by chemical immobilization of β-cyclodextrin functional groups on an aerosilogel (highly dispersed type of amorphous silica). A β-cyclodextrin-containing aerosilogel was synthesized by two-stage liquid-phase chemical modification of hydroxylated silica surface. Using the methods of IR spectroscopy, spectrophotometry, thermogravimetry, pH metry, low-temperature adsorption-desorption of nitrogen, chemical and elemental analysis of the surface, the surface structure and its quantitative chemical composition, and also parameters of porous structure of initial and chemically modified aerosilogels were determined. Sorption of benzoic, salicylic and β-resorcylic acids on aerosilogels from aqueous buffer solutions with pH=1 was studied. The insignificant contribution of silanol and aminopropyl groups and complete participation of chemically fixed β-cyclodextrin in the sorption of aromatic acids were proved. The results obtained are analyzed using kinetic models for pseudo-first and pseudo-second order processes, as well as Langmuir and Freundlich models for equilibrium adsorption on homogeneous and heterogeneous surfaces. It has been found that the sorption kinetic processes are well described by a pseudo-first order equation (in the presence of one type of functional groups on the surface) and a pseudo-second order equation for bi- and trifunctional aerosilogels. Experimental results on the equilibrium sorption of aromatic acids on β-cyclodextrin-containing aerosilogel are in good agreement with the Langmuir adsorption equation. This is evidence of decisive contribution of grafted oligosaccharide groups to the sorption of organic acids. The proposed chemical approach to increasing the sorption activity of aerosilogel can be used to obtain specific chromatographic carriers, as well as inorganic sorbents for the effective removal of small amounts of highly toxic organic substances from water and aqueous solutions.
{"title":"Synthesis and sorption properties of β-cyclodextrin-containing aerosilogel","authors":"L. Belyakova, D. Lyashenko","doi":"10.15407/hftp14.01.019","DOIUrl":"https://doi.org/10.15407/hftp14.01.019","url":null,"abstract":"Aromatic organic acids are among the common environmental pollutants that enter the water with washouts from agricultural lands, wastewater from chemical and pharmaceutical industries. Taking into account the high toxicity of aromatic substances, the important task of water purification is the removal of their trace amounts. This problem can be solved by using chemically modified inorganic materials, such as silicas, which have high mechanical, chemical, hydrolytic, and radiation stability. Therefore, they do not lose their sorption capacity during long-term use and do not pollute water with sorbent degradation products. The purpose of this work is the synthesis of a sorption-active material for removal of toxic aromatic acids by chemical immobilization of β-cyclodextrin functional groups on an aerosilogel (highly dispersed type of amorphous silica). A β-cyclodextrin-containing aerosilogel was synthesized by two-stage liquid-phase chemical modification of hydroxylated silica surface. Using the methods of IR spectroscopy, spectrophotometry, thermogravimetry, pH metry, low-temperature adsorption-desorption of nitrogen, chemical and elemental analysis of the surface, the surface structure and its quantitative chemical composition, and also parameters of porous structure of initial and chemically modified aerosilogels were determined. Sorption of benzoic, salicylic and β-resorcylic acids on aerosilogels from aqueous buffer solutions with pH=1 was studied. The insignificant contribution of silanol and aminopropyl groups and complete participation of chemically fixed β-cyclodextrin in the sorption of aromatic acids were proved. The results obtained are analyzed using kinetic models for pseudo-first and pseudo-second order processes, as well as Langmuir and Freundlich models for equilibrium adsorption on homogeneous and heterogeneous surfaces. It has been found that the sorption kinetic processes are well described by a pseudo-first order equation (in the presence of one type of functional groups on the surface) and a pseudo-second order equation for bi- and trifunctional aerosilogels. Experimental results on the equilibrium sorption of aromatic acids on β-cyclodextrin-containing aerosilogel are in good agreement with the Langmuir adsorption equation. This is evidence of decisive contribution of grafted oligosaccharide groups to the sorption of organic acids. The proposed chemical approach to increasing the sorption activity of aerosilogel can be used to obtain specific chromatographic carriers, as well as inorganic sorbents for the effective removal of small amounts of highly toxic organic substances from water and aqueous solutions.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123286627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During the preparation of silicon substrates for the manufacture of silicon p-i-n photodiodes, the effect of the presence of chemical-dynamic polishing and the depth of etching on the electrical parameters of the FD was observed. The quality of the polishing operation also affected the optical and photoelectric parameters of the samples. These effects required detailed study. The article investigates defect formation during the operation of chemical-dynamic polishing in the technology of silicon p-i-n FDs and determines the optimal modes of polishing the front and back sides of the substrates. The composition of the etching mixture was HNO3:HF:CH3COOH = 9:2:4. CDP has a significant effect on dark currents. This operation should be performed before heat treatments and before diffusion in the reverse direction to obtain minimum values of the dark current. The optimal polishing depth of the front side of the substrate is 20–25 microns (if we take into account the etching of the reverse side – 35–40 microns in total), the reverse side before boron diffusion – 10–15 microns. The main factors that affect the appearance of defects during polishing have been elucidated. Thus, when the concentration of the components of the polisher medicine for the СDP changes significantly, its properties change significantly – the polisher can become selective, since its composition is similar to the selective polisher of Dash. In order to avoid this, it is necessary to carry out incoming control of component acids. If there are inclusions of another phase in the volume of ingots and, accordingly, on the surface of the substrates, clusters of point microdefects of different sizes, or defects acquired in the process of mechanical processing, there is unevenness of etching and violation of planar parallelism. At a high speed of rotation of the tank with the polisher, the depleted layer of the solution may not have time to form near the surface of the substrates or be “broken off” from the surface by the flow of liquid, which leads to selective etching of the plates. This effect can be manifested in the so-called texturing of substrates, which increases the level of dark current and reduces sensitivity. In the case of the reverse side of the СDP, before boron diffusion, the front side is protected with a chemically resistant varnish. If the thickness of the varnish is insufficient, the formation of punctures in the protective layer is possible. In this case, during the polishing operation, the herbaceous material flows under the varnish layer and the brightening or masking oxide is etched. To prevent the described phenomena, we recommend applying two layers of varnish with intermediate drying. Before the end of the polishing process, it is inadmissible to remove the plates from the container with the herbal agent, because drops of the herbal agent remain on the surface of the substrates. In places where there are drops, a violent reaction begins with the release of nitric
{"title":"Problems of chemical-dynamic polishing in the technology of silicon p-i-n photodiodes","authors":"M. Kukurudziak","doi":"10.15407/hftp14.01.042","DOIUrl":"https://doi.org/10.15407/hftp14.01.042","url":null,"abstract":"During the preparation of silicon substrates for the manufacture of silicon p-i-n photodiodes, the effect of the presence of chemical-dynamic polishing and the depth of etching on the electrical parameters of the FD was observed. The quality of the polishing operation also affected the optical and photoelectric parameters of the samples. These effects required detailed study. The article investigates defect formation during the operation of chemical-dynamic polishing in the technology of silicon p-i-n FDs and determines the optimal modes of polishing the front and back sides of the substrates. The composition of the etching mixture was HNO3:HF:CH3COOH = 9:2:4. CDP has a significant effect on dark currents. This operation should be performed before heat treatments and before diffusion in the reverse direction to obtain minimum values of the dark current. The optimal polishing depth of the front side of the substrate is 20–25 microns (if we take into account the etching of the reverse side – 35–40 microns in total), the reverse side before boron diffusion – 10–15 microns. The main factors that affect the appearance of defects during polishing have been elucidated. Thus, when the concentration of the components of the polisher medicine for the СDP changes significantly, its properties change significantly – the polisher can become selective, since its composition is similar to the selective polisher of Dash. In order to avoid this, it is necessary to carry out incoming control of component acids. If there are inclusions of another phase in the volume of ingots and, accordingly, on the surface of the substrates, clusters of point microdefects of different sizes, or defects acquired in the process of mechanical processing, there is unevenness of etching and violation of planar parallelism. At a high speed of rotation of the tank with the polisher, the depleted layer of the solution may not have time to form near the surface of the substrates or be “broken off” from the surface by the flow of liquid, which leads to selective etching of the plates. This effect can be manifested in the so-called texturing of substrates, which increases the level of dark current and reduces sensitivity. In the case of the reverse side of the СDP, before boron diffusion, the front side is protected with a chemically resistant varnish. If the thickness of the varnish is insufficient, the formation of punctures in the protective layer is possible. In this case, during the polishing operation, the herbaceous material flows under the varnish layer and the brightening or masking oxide is etched. To prevent the described phenomena, we recommend applying two layers of varnish with intermediate drying. Before the end of the polishing process, it is inadmissible to remove the plates from the container with the herbal agent, because drops of the herbal agent remain on the surface of the substrates. In places where there are drops, a violent reaction begins with the release of nitric","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125449164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Kolomiiets, O. V. Palchik, Y. Dzyazko, T. Yatsenko, L. M. Ponomaryova, V. Ogenko
Oil and oil products enters surface waters as a result of man-made disasters, caused, in particular, by military operations. In order to prevent ecological catastrophe, it is necessary to remove hydrocarbons from water surface. The paper is devoted to the development of materials for the extraction of non-polar liquids from aqueous media. Magnetic sorbents based on non-carbonized biopolymers (both plant cellulose and keratin) are proposed. Biopolymer matrices of different morphology on the level of fiber bundles were used for the composite preparation. Dependent on origin, the matrices are characterized by different morphologies at the level of fiber bundles: they are straight (cellulose obtained from wood and corn cobs), helical (cellulose of tea leaves or scaly (keratin from animal wool). Magnetite particles were inserted into biopolymer matrices after the removal of non-cellulose and non-keratin inclusions from them. The samples were investigated with SEM and FTIR techniques, magnetite was identified with XRD analysis. The most homogeneous distribution of magnetic particles, a size of which is less than 1 mm, was found for the matrix obtained from corn cobs. This composite contained the least amount of iron (0.24 mass. %), namely this sample demonstrates the best flotation. The sorbent based on cellulose from tea leaves contained 71% of iron: the particles sink almost completely. The capacity towards non-polar liquids was estimated as follows (g g–1): 1.6–8.6 (vegetable oil), 10.5–16.4 (crude oil), 9.8–14.5 (kerosene). After the removal of crude oil from water surface, no film of this liquid was visually observed. The value of chemical oxygen demand was » 0.2 mgO2 dm–3, this is less than the demand for drinking water. Moreover, the sorbent can be easy removed from water surface with magnet. As found, the sorbents can be used for removal of toxic metal ions from water. As found, magnetic particles improves sorption of Pb2+ ions but decrease Cd2+ sorption. Thus, the sorbents with small content of inorganic modifier can be used for the removal of oil and oil products from water surface. The sorbents, which demonstrate bad flotation, can be used for the recovery of inorganic ions. The advantages of biopolymer-based sorbents over known material is a simple preparation procedure that involves cheap and available feedstock. Moreover, the sorbents can be easy separated from aqueous phase with magnet.
石油和石油产品进入地表水是人为灾害，特别是军事行动造成的灾害的结果。为了防止生态灾难，有必要从水面去除碳氢化合物。本文致力于研制从水介质中提取非极性液体的材料。提出了基于非碳化生物聚合物(包括植物纤维素和角蛋白)的磁性吸附剂。在纤维束水平上采用不同形态的生物聚合物基质制备复合材料。根据来源的不同，这些基质在纤维束水平上具有不同的形态特征:它们是直的(取自木材和玉米芯的纤维素)，螺旋的(取自茶叶的纤维素)或鳞状的(取自动物羊毛的角蛋白)。在去除非纤维素和非角蛋白内含物后，将磁铁矿颗粒插入生物聚合物基质中。用扫描电镜(SEM)和红外光谱(FTIR)对样品进行了表征，用x射线衍射(XRD)对样品进行了鉴定。从玉米芯中获得的基质中发现磁性颗粒分布最均匀，其尺寸小于1mm。这种复合材料含有最少的铁(0.24质量)。%)，即该样品具有最佳浮选效果。基于茶叶纤维素的吸附剂含有71%的铁:颗粒几乎完全下沉。非极性液体的容量估计如下(g g - 1): 1.6-8.6(植物油)、10.5-16.4(原油)、9.8-14.5(煤油)。从水面去除原油后，肉眼未观察到该液体的膜层。化学需氧量为0.2 mgO2 dm-3，低于饮用水需氧量。此外，吸附剂可以很容易地从水面磁铁去除。结果表明，该吸附剂可用于去除水中的有毒金属离子。结果表明，磁性颗粒对Pb2+离子的吸附作用增强，对Cd2+离子的吸附作用减弱。因此，无机改性剂含量低的吸附剂可用于去除水面的油及油品。该吸附剂浮选效果较差，可用于无机离子的回收。与已知材料相比，生物聚合物基吸附剂的优点是制备过程简单，涉及廉价和可用的原料。此外，吸附剂可以很容易地与水相分离。
{"title":"Sorbents based on biopolymers of different origin containing magnetite for removal of oil products and toxic ions from water","authors":"V. Kolomiiets, O. V. Palchik, Y. Dzyazko, T. Yatsenko, L. M. Ponomaryova, V. Ogenko","doi":"10.15407/hftp14.01.121","DOIUrl":"https://doi.org/10.15407/hftp14.01.121","url":null,"abstract":"Oil and oil products enters surface waters as a result of man-made disasters, caused, in particular, by military operations. In order to prevent ecological catastrophe, it is necessary to remove hydrocarbons from water surface. The paper is devoted to the development of materials for the extraction of non-polar liquids from aqueous media. Magnetic sorbents based on non-carbonized biopolymers (both plant cellulose and keratin) are proposed. Biopolymer matrices of different morphology on the level of fiber bundles were used for the composite preparation. Dependent on origin, the matrices are characterized by different morphologies at the level of fiber bundles: they are straight (cellulose obtained from wood and corn cobs), helical (cellulose of tea leaves or scaly (keratin from animal wool). Magnetite particles were inserted into biopolymer matrices after the removal of non-cellulose and non-keratin inclusions from them. The samples were investigated with SEM and FTIR techniques, magnetite was identified with XRD analysis. The most homogeneous distribution of magnetic particles, a size of which is less than 1 mm, was found for the matrix obtained from corn cobs. This composite contained the least amount of iron (0.24 mass. %), namely this sample demonstrates the best flotation. The sorbent based on cellulose from tea leaves contained 71% of iron: the particles sink almost completely. The capacity towards non-polar liquids was estimated as follows (g g–1): 1.6–8.6 (vegetable oil), 10.5–16.4 (crude oil), 9.8–14.5 (kerosene). After the removal of crude oil from water surface, no film of this liquid was visually observed. The value of chemical oxygen demand was » 0.2 mgO2 dm–3, this is less than the demand for drinking water. Moreover, the sorbent can be easy removed from water surface with magnet. As found, the sorbents can be used for removal of toxic metal ions from water. As found, magnetic particles improves sorption of Pb2+ ions but decrease Cd2+ sorption. Thus, the sorbents with small content of inorganic modifier can be used for the removal of oil and oil products from water surface. The sorbents, which demonstrate bad flotation, can be used for the recovery of inorganic ions. The advantages of biopolymer-based sorbents over known material is a simple preparation procedure that involves cheap and available feedstock. Moreover, the sorbents can be easy separated from aqueous phase with magnet.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"41 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127985639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：