The behavior of the diagonal components of the dielectric tensor and the behavior of the absorption cross-section in the different frequency ranges for the composite cylindrical nanostructures “metallic core – graphene shell” have been studied. In order to obtain the calculation formulas one uses the relations for the longitudinal and transverse components of the dielectric tensors for metallic core and graphene shell, which are determined by Drude model and Cubo model correspondingly. The consideration is carried out in the frameworks of “equivalent” elongated spheroid approach, according to which the defining dimensional parameter is effective aspect ratio, calculated from the condition of the equality of the corresponding axial inertia moments for two-layer cylinder and the “equivalent” elongated spheroid. The numerical results have been obtained for the nanocylinders with the cores of different metals, different radius and with the different number of graphene layers. The variation of amplitude and the variation of the location of extremes of the real and imaginary parts of the transverse component of the dielectric tensor under the increase in radius of the metallic core and the thickness of the graphene shell have been analyzed. It has been shown that the variation of the radius of the core has the significantly greater influence on the properties of the polarizability resonances and absorption cross-section than the variation of the number of graphene layers. The reasons of the presence of two maxima of the absorption cross-section for the metal-graphene cylinders which differ in both amplitude and width and located in infrared, violet and near ultraviolet parts of the spectrum and their relation with the surface plasmonic resonances in the metallic core and with the terahertz plasmons of graphene have been found. The factors which have an effect on amplitude and on the shift of the maxima of the absorption cross-section have been found. The reasons of the different width of maxima, which are located in the different spectral intervals, have been determined.
{"title":"Dielectric function and the absorption cross-section of the metal-graphene nanocylinders of the finite length","authors":"Ya. V. Karandas, A. Korotun","doi":"10.15407/hftp13.04.467","DOIUrl":"https://doi.org/10.15407/hftp13.04.467","url":null,"abstract":"The behavior of the diagonal components of the dielectric tensor and the behavior of the absorption cross-section in the different frequency ranges for the composite cylindrical nanostructures “metallic core – graphene shell” have been studied. In order to obtain the calculation formulas one uses the relations for the longitudinal and transverse components of the dielectric tensors for metallic core and graphene shell, which are determined by Drude model and Cubo model correspondingly. The consideration is carried out in the frameworks of “equivalent” elongated spheroid approach, according to which the defining dimensional parameter is effective aspect ratio, calculated from the condition of the equality of the corresponding axial inertia moments for two-layer cylinder and the “equivalent” elongated spheroid. The numerical results have been obtained for the nanocylinders with the cores of different metals, different radius and with the different number of graphene layers. The variation of amplitude and the variation of the location of extremes of the real and imaginary parts of the transverse component of the dielectric tensor under the increase in radius of the metallic core and the thickness of the graphene shell have been analyzed. It has been shown that the variation of the radius of the core has the significantly greater influence on the properties of the polarizability resonances and absorption cross-section than the variation of the number of graphene layers. The reasons of the presence of two maxima of the absorption cross-section for the metal-graphene cylinders which differ in both amplitude and width and located in infrared, violet and near ultraviolet parts of the spectrum and their relation with the surface plasmonic resonances in the metallic core and with the terahertz plasmons of graphene have been found. The factors which have an effect on amplitude and on the shift of the maxima of the absorption cross-section have been found. The reasons of the different width of maxima, which are located in the different spectral intervals, have been determined.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125172117","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}
E. Demianenko, M. Terets, L. Ushakova, S. Zhuravskyi, Y. Sementsov, V. Lobanov, O. Filonenko, V. Kuts, A. Grebenyuk, M. Kartel
It is known that the addition of a small amount of carbon nanomaterials significantly improves the mechanical properties of composites with a metal matrix. One of the most important, promising and available metals as a matrix for such modification is aluminum. However, at the interface between the carbon material and Al, aluminum carbides of different composition are formed, which are brittle and have the main disadvantage - solubility in water. Therefore, the appearance of aluminum carbide is a serious problem, since it contributes to the formation of defects, which, when the composite is deformed, leads to cracking of the composite due to the presence of microneedles. In this regard, in order to predict the features of the interaction of aluminum itself with the surface of carbon nanomaterials, it is advisable to model such processes using quantum chemistry methods. The aim of the work was to reveal the effect of temperature on the chemical interaction of aluminum clusters with native, boron-, silicon-, and nitrogen-containing graphene-like planes (GLP). All the calculated by three methods (B3LYP/6-31G(d,p), MP2/6-31G(d,p) and PВЕ0/6-31G(d,p)) values of the dependence of the Gibbs free energy on temperature for different cluster sizes of aluminum and graphene-like clusters are the highest for native graphene-like planes. In all cases, the values of the Gibbs free energy increase with temperature. The lowest values of the temperature dependence of the Gibbs free energy vary as dependent on the size of the reactant models and research methods, this is especially characteristic of the presence of boron and silicon atoms in the graphene-like clusters. Therefore, the absence of heteroatoms in the composition of the nanocarbon matrix contributes to the fact that aluminum carbide islands should not be formed in the carbon-containing nanocomposite with aluminum, which negatively affects the physical and chemical characteristics of the resulting nanocomposite.
{"title":"A theoretical study on the effect of heteroatoms (N, B, Si) on the interaction of aluminum clusters with a carbon graphene-like plane","authors":"E. Demianenko, M. Terets, L. Ushakova, S. Zhuravskyi, Y. Sementsov, V. Lobanov, O. Filonenko, V. Kuts, A. Grebenyuk, M. Kartel","doi":"10.15407/hftp13.04.391","DOIUrl":"https://doi.org/10.15407/hftp13.04.391","url":null,"abstract":"It is known that the addition of a small amount of carbon nanomaterials significantly improves the mechanical properties of composites with a metal matrix. One of the most important, promising and available metals as a matrix for such modification is aluminum. However, at the interface between the carbon material and Al, aluminum carbides of different composition are formed, which are brittle and have the main disadvantage - solubility in water. Therefore, the appearance of aluminum carbide is a serious problem, since it contributes to the formation of defects, which, when the composite is deformed, leads to cracking of the composite due to the presence of microneedles. In this regard, in order to predict the features of the interaction of aluminum itself with the surface of carbon nanomaterials, it is advisable to model such processes using quantum chemistry methods. The aim of the work was to reveal the effect of temperature on the chemical interaction of aluminum clusters with native, boron-, silicon-, and nitrogen-containing graphene-like planes (GLP). All the calculated by three methods (B3LYP/6-31G(d,p), MP2/6-31G(d,p) and PВЕ0/6-31G(d,p)) values of the dependence of the Gibbs free energy on temperature for different cluster sizes of aluminum and graphene-like clusters are the highest for native graphene-like planes. In all cases, the values of the Gibbs free energy increase with temperature. The lowest values of the temperature dependence of the Gibbs free energy vary as dependent on the size of the reactant models and research methods, this is especially characteristic of the presence of boron and silicon atoms in the graphene-like clusters. Therefore, the absence of heteroatoms in the composition of the nanocarbon matrix contributes to the fact that aluminum carbide islands should not be formed in the carbon-containing nanocomposite with aluminum, which negatively affects the physical and chemical characteristics of the resulting nanocomposite.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121527544","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}
T. Tkachenko, D. Kamenskyh, Y. Sheludko, V. Yevdokymenko
The main idea of this work is to study the possibility of obtaining microcrystalline cellulose from multi-ton and low-value agricultural waste and investigation its structural properties. Air-dry soybean straw, an agricultural waste, was used for the research. Microcrystalline cellulose (MCC) was obtained from it by the method of organo-solvent cooking. Using the methods of XRD, XRF, FTIR-ATR, AFM, TGA and DSC, the structure and morphology of MCC were studied. It is found that increasing the hydromodule reduces the content of lignin and inorganic components. At the same time, both the yields of the MCC and its qualitative characteristics are declining. First of all, the crystallinity index of the MCC decreases with the increasing amount of the liquor ration. The band corresponded to symmetric CH2 bendings at 1435–1429 cm–1, that is known as the crystallinity band, decreased with increasing amount of the liquor ration. The AFM method shows that when forming the surfaces of MCC 10 particles, not only groups of particles are formed, the heights of the elements of which range from 23.8–28.1 to 16.9–26.8 nm, but also elongated units on the surface of which there are individual particles. The surface roughness is 1.6 nm. At the same time, the surface of the MCC 15 has a surface roughness Ra = 3.1 nm. The particles are distributed throughout the scan, with no clusters of particles and their agglomerates, and their heights are 14.4; 18.7; 20.6; 17.4 and 23.9; 18.1; 24.7 nm. 3D image of the particles showed that the particles are pyramids of different configurations similar to the particles in the MCC 10. It should be noted that the range of depressions and heights characteristic of MCC 15 is much smaller (from –13 to +20.7 nm) than in the MCC 10 (from –17.5 to 45.5 nm).
{"title":"Structural and morphological features of microcrystalline сellulose from soybean straw by organosolvent treatment","authors":"T. Tkachenko, D. Kamenskyh, Y. Sheludko, V. Yevdokymenko","doi":"10.15407/hftp13.04.455","DOIUrl":"https://doi.org/10.15407/hftp13.04.455","url":null,"abstract":"The main idea of this work is to study the possibility of obtaining microcrystalline cellulose from multi-ton and low-value agricultural waste and investigation its structural properties. Air-dry soybean straw, an agricultural waste, was used for the research. Microcrystalline cellulose (MCC) was obtained from it by the method of organo-solvent cooking. Using the methods of XRD, XRF, FTIR-ATR, AFM, TGA and DSC, the structure and morphology of MCC were studied. It is found that increasing the hydromodule reduces the content of lignin and inorganic components. At the same time, both the yields of the MCC and its qualitative characteristics are declining. First of all, the crystallinity index of the MCC decreases with the increasing amount of the liquor ration. The band corresponded to symmetric CH2 bendings at 1435–1429 cm–1, that is known as the crystallinity band, decreased with increasing amount of the liquor ration. The AFM method shows that when forming the surfaces of MCC 10 particles, not only groups of particles are formed, the heights of the elements of which range from 23.8–28.1 to 16.9–26.8 nm, but also elongated units on the surface of which there are individual particles. The surface roughness is 1.6 nm. At the same time, the surface of the MCC 15 has a surface roughness Ra = 3.1 nm. The particles are distributed throughout the scan, with no clusters of particles and their agglomerates, and their heights are 14.4; 18.7; 20.6; 17.4 and 23.9; 18.1; 24.7 nm. 3D image of the particles showed that the particles are pyramids of different configurations similar to the particles in the MCC 10. It should be noted that the range of depressions and heights characteristic of MCC 15 is much smaller (from –13 to +20.7 nm) than in the MCC 10 (from –17.5 to 45.5 nm).","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127626491","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}
A. Kasumov, A. Dmitriev, K. A. Korotko, V. Karavaeva, K. O. Vyshnevska, A. Ievtushenko
A review of the works of the authors published in the period 2009–2022 and devoted to the study of the properties of nanosized structures containing contacting layers of Fe, Co, Ni, Fe2O3 / REM (Rare Earth Metal) oxide is carried out. The technology for the creation and structural features of these nanostructures are also considered. Physicochemical phenomena in the interface of contacting layers are very multidisciplinary. This is a consequence of their dependence on various conditions, primarily on the modes of technologies for their production and the properties of the initial components. The problem becomes much more complicated when studying magnetic nanostructures. To study effectively the properties of layered nanostructures containing ferromagnetic films, we used magnetic research methods. Using the EPR method, it has been found that between atoms with unfilled f- and d-electron sub-shells, which are part of the contacting layers, an f-d exchange interaction occurs, which orders the magnetic structure of the ferromagnetic layers. Using the method of the anomalous Hall effect, it is shown that the ordering of the magnetic structure leads to an increase in their magnetization. The enhancement of the galvanomagnetic properties in the Fe3O4/REМ оxide/Fe3O4 structures shows that the exchange interaction can have both f-d and d-d character. And this, in turn, leads to an increase in magnetization-dependent properties, such as galvanomagnetic, magneto-optical, and current-voltage properties. This can be used in nanotechnologies to enhance the above properties without energy consumption and the use of amplifying equipment.
{"title":"Influence of f-d exchange interaction on the properties of nanoscale structures based on Fe, Co, Ni metals and rem oxides. A review","authors":"A. Kasumov, A. Dmitriev, K. A. Korotko, V. Karavaeva, K. O. Vyshnevska, A. Ievtushenko","doi":"10.15407/hftp13.04.434","DOIUrl":"https://doi.org/10.15407/hftp13.04.434","url":null,"abstract":"A review of the works of the authors published in the period 2009–2022 and devoted to the study of the properties of nanosized structures containing contacting layers of Fe, Co, Ni, Fe2O3 / REM (Rare Earth Metal) oxide is carried out. The technology for the creation and structural features of these nanostructures are also considered. Physicochemical phenomena in the interface of contacting layers are very multidisciplinary. This is a consequence of their dependence on various conditions, primarily on the modes of technologies for their production and the properties of the initial components. The problem becomes much more complicated when studying magnetic nanostructures. To study effectively the properties of layered nanostructures containing ferromagnetic films, we used magnetic research methods. Using the EPR method, it has been found that between atoms with unfilled f- and d-electron sub-shells, which are part of the contacting layers, an f-d exchange interaction occurs, which orders the magnetic structure of the ferromagnetic layers. Using the method of the anomalous Hall effect, it is shown that the ordering of the magnetic structure leads to an increase in their magnetization. The enhancement of the galvanomagnetic properties in the Fe3O4/REМ оxide/Fe3O4 structures shows that the exchange interaction can have both f-d and d-d character. And this, in turn, leads to an increase in magnetization-dependent properties, such as galvanomagnetic, magneto-optical, and current-voltage properties. This can be used in nanotechnologies to enhance the above properties without energy consumption and the use of amplifying equipment.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128759246","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 ratchet effect is a directed nanoparticle flux phenomenon induced by nonequilibrium fluctuations in a system with spatial and (or) temporal asymmetry. One is used as the way to create a controlled nanotransport and is the basis of the theory of Brownian motors. Fluctuation motion simulation is a promising way to calculate the main characteristics of Brownian motors, it avoids complex calculations and quickly obtains predictions about the appearance or absence of generated directional motion in a specific model. Nonequilibrium fluctuations are usually introduced into the system by a dichotomous process that switches two periodic asymmetric potential profiles at certain fixed intervals (deterministic process), or randomly with average potential lifetimes (stochastic process). We investigate the modeling of the process of the ratchet effect in the framework of the Brownian motor jump-like model by the method of Parrondo’s paradoxical game for the stochastic dichotomous process and compare results with a similar deterministic process. A calculus method for the main characteristics obtaining of the motor with stochastic dichotomous process is proposed, it is shown correspondence to the analytical description of this model in extreme cases. It is shown that the stochasticity of the process directly affects the characteristics of the ratchet effect: the trajectories of the average displacements of nanoparticles fundamentally differs in the deterministic description, and a gradual difference in these processes is observed at low values. The study of asymmetric dichotomous processes for different temperature modes of motor operation is carried out. The model allows one to analyze the peculiarities of the directional motion starting at the level of single jumps, as well as to formulate recommendations for possible improvement of motor efficiency for different temperatures. For high-temperature mode, it is advisable to reduce the lifetime of the state with the active potential, and for low-temperature mode, arbitrary, it should be increased.
{"title":"Ratchet effect modeling by method of paradoxical games for stochastic fluctuations of double-well potential","authors":"A. D. Terets, V. A. Mashira, T. Korochkova","doi":"10.15407/hftp13.03.338","DOIUrl":"https://doi.org/10.15407/hftp13.03.338","url":null,"abstract":"The ratchet effect is a directed nanoparticle flux phenomenon induced by nonequilibrium fluctuations in a system with spatial and (or) temporal asymmetry. One is used as the way to create a controlled nanotransport and is the basis of the theory of Brownian motors. Fluctuation motion simulation is a promising way to calculate the main characteristics of Brownian motors, it avoids complex calculations and quickly obtains predictions about the appearance or absence of generated directional motion in a specific model. Nonequilibrium fluctuations are usually introduced into the system by a dichotomous process that switches two periodic asymmetric potential profiles at certain fixed intervals (deterministic process), or randomly with average potential lifetimes (stochastic process). We investigate the modeling of the process of the ratchet effect in the framework of the Brownian motor jump-like model by the method of Parrondo’s paradoxical game for the stochastic dichotomous process and compare results with a similar deterministic process. A calculus method for the main characteristics obtaining of the motor with stochastic dichotomous process is proposed, it is shown correspondence to the analytical description of this model in extreme cases. It is shown that the stochasticity of the process directly affects the characteristics of the ratchet effect: the trajectories of the average displacements of nanoparticles fundamentally differs in the deterministic description, and a gradual difference in these processes is observed at low values. The study of asymmetric dichotomous processes for different temperature modes of motor operation is carried out. The model allows one to analyze the peculiarities of the directional motion starting at the level of single jumps, as well as to formulate recommendations for possible improvement of motor efficiency for different temperatures. For high-temperature mode, it is advisable to reduce the lifetime of the state with the active potential, and for low-temperature mode, arbitrary, it should be increased.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"108 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114048757","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}
For various adsorbents, especially nanoporous, there is an applicability problem of the Brunauer-Emmett-Teller (BET) method using nitrogen as a probe adsorbate. Therefore, the nitrogen adsorption (a(p/p0)) isotherms in several pressure ranges of the BET method at p/p0 = 0.05–0.3, 0.06–0.22, and narrower are analyzed for a large set (about 200 samples) of essentially different adsorbents such as fumed oxides (individual, binary and ternary, initial and modified), porous silicas, activated carbons and porous polymers. Graphitized carbon black ENVI–Carb composed of nonporous nanoparticles aggregated into microparticles is used as a standard adsorbent characterized by the standard area occupied by nitrogen molecule σm(N2) = 0.162 nm2. For initial nanooxides composed of nonporous nanoparticles, the standard value of σm = 0.162 nm2 results in the overestimation of the SBET values by ca. 10 % because of non-parallel-to-surface orientation of slightly polarized N2 molecules interacting with polar surface functionalities (e.g., various hydroxyls). For nanooxides modified by low- and high-molecular (linear, 2D and 3D polymers and proteins) compounds, the overestimation of SBET at σm = 0.162 nm2 could reach 30 %, as well as for some activated carbons. For adsorbents possessing nanopores (at half-width x or radius R < 1 nm) and narrow mesopores (1 nm < R < 3 nm), an overlap of monolayer and multilayer sorption (giving apparent underestimation of SBET at σm = 0.162 nm2) and non-parallel-to-surface orientation of the N2 molecules (causing σm lower than 0.162 nm2) could lead to various location of the normalized nitrogen adsorption isotherms (in the BET range) with respect to that for ENVI–Carb. It could be characterized by positive or negative values of the BET constant cBET. Two main criteria showing the inapplicability or applicability of the BET method (with nitrogen as a probe) related to the cBET values and a course of reduced adsorption a´(1- p/p0) vs. p/p0 in the BET range could not be in agreement for adsorbents, which are not pure nanoporous, but they are in agreement for pure nanoporous or meso/macroporous adsorbents
{"title":"Features of BET method application to various adsorbents","authors":"V. Gun'ko","doi":"10.15407/hftp13.03.249","DOIUrl":"https://doi.org/10.15407/hftp13.03.249","url":null,"abstract":"For various adsorbents, especially nanoporous, there is an applicability problem of the Brunauer-Emmett-Teller (BET) method using nitrogen as a probe adsorbate. Therefore, the nitrogen adsorption (a(p/p0)) isotherms in several pressure ranges of the BET method at p/p0 = 0.05–0.3, 0.06–0.22, and narrower are analyzed for a large set (about 200 samples) of essentially different adsorbents such as fumed oxides (individual, binary and ternary, initial and modified), porous silicas, activated carbons and porous polymers. Graphitized carbon black ENVI–Carb composed of nonporous nanoparticles aggregated into microparticles is used as a standard adsorbent characterized by the standard area occupied by nitrogen molecule σm(N2) = 0.162 nm2. For initial nanooxides composed of nonporous nanoparticles, the standard value of σm = 0.162 nm2 results in the overestimation of the SBET values by ca. 10 % because of non-parallel-to-surface orientation of slightly polarized N2 molecules interacting with polar surface functionalities (e.g., various hydroxyls). For nanooxides modified by low- and high-molecular (linear, 2D and 3D polymers and proteins) compounds, the overestimation of SBET at σm = 0.162 nm2 could reach 30 %, as well as for some activated carbons. For adsorbents possessing nanopores (at half-width x or radius R < 1 nm) and narrow mesopores (1 nm < R < 3 nm), an overlap of monolayer and multilayer sorption (giving apparent underestimation of SBET at σm = 0.162 nm2) and non-parallel-to-surface orientation of the N2 molecules (causing σm lower than 0.162 nm2) could lead to various location of the normalized nitrogen adsorption isotherms (in the BET range) with respect to that for ENVI–Carb. It could be characterized by positive or negative values of the BET constant cBET. Two main criteria showing the inapplicability or applicability of the BET method (with nitrogen as a probe) related to the cBET values and a course of reduced adsorption a´(1- p/p0) vs. p/p0 in the BET range could not be in agreement for adsorbents, which are not pure nanoporous, but they are in agreement for pure nanoporous or meso/macroporous adsorbents","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114796782","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}
O. Zolotarenko, E. Rudakova, A. Zolotarenko, N. Akhanova, M. Ualkhanova, D. Shchur, M. Gabdullin, N. Gavrylyuk, T. Myronenko, M. Chymbai, I. Zagorulko, Yuriy O. Tarasenko, O. Havryliuk
Carbon nanostructures (CNS) were synthesized by the electric arc plasma chemical method during the evaporation of a high-quality graphite electrode of the brand “fine-grained dense graphite” (FGDG-7) filled with a catalyst (Pt), which was evaporated in a helium environment. In the synthesis process, the following were synthesized: multi-walled (MWCNT) and single-walled carbon nanotubes (SWCNT), fullerenes, graphene packets and nanocomposites. A deposit in the form of growth on the cathode electrode was also synthesized. All synthesis products were analyzed at the micro- and nanolevels, which made it possible to analyze the influence of platinum vapors on the formation of carbon nanomaterials (CNM). The non-uniform distribution of catalyst atoms (platinum) in the products of electrochemical synthesis in a gas medium using FGDG-7 graphite was investigated. During the analysis, it was found that platinum is in the state of the face-centered cubic (FCC) lattice and is distributed in the synthesis products as follows: the core of the deposit is less than < 0.001 %, the shell of the deposit is less than < 1 %, the wall soot is more than > 1 %. The morphology and composition of the platinum deposit, which has a hexagonal graphite structure with an admixture of a rhombohedral graphite phase, was studied. In the studies, differential thermal analysis in air (TG, DTG, DTA) was carried out, which made it possible to identify the composition of the synthesis products. It is an established fact that the parts of the deposit with platinum are more heat-resistant compared to the deposit components that do not contain Pt. The resulting carbon nanotubes (CNTs) in diameter (5–25 nm) and length (1.5–2 μm) do not differ from those obtained without the participation of platinum, except for some anomalies. When studying the suitability of platinum-containing carbon nanostructures for 3D printing of CJP (ceramic printing) technology, it was found that for the use of platinum-containing carbon black, it is necessary to carry out a preliminary short-term treatment, namely, grinding in special “ball mills” or rubbing through a fine sieve with minimal effort to create uniformity product. Previous studies have shown that such platinum-containing carbon nanostructures can already be used in 3D printing of CJP technology, or to create new composites for 3D printing technologies of FDM, SLA.
{"title":"Platinum-containing carbon nanostructures for the creation of electrically conductive ceramics using 3D printing of CJP technology","authors":"O. Zolotarenko, E. Rudakova, A. Zolotarenko, N. Akhanova, M. Ualkhanova, D. Shchur, M. Gabdullin, N. Gavrylyuk, T. Myronenko, M. Chymbai, I. Zagorulko, Yuriy O. Tarasenko, O. Havryliuk","doi":"10.15407/hftp13.03.259","DOIUrl":"https://doi.org/10.15407/hftp13.03.259","url":null,"abstract":"Carbon nanostructures (CNS) were synthesized by the electric arc plasma chemical method during the evaporation of a high-quality graphite electrode of the brand “fine-grained dense graphite” (FGDG-7) filled with a catalyst (Pt), which was evaporated in a helium environment. In the synthesis process, the following were synthesized: multi-walled (MWCNT) and single-walled carbon nanotubes (SWCNT), fullerenes, graphene packets and nanocomposites. A deposit in the form of growth on the cathode electrode was also synthesized. All synthesis products were analyzed at the micro- and nanolevels, which made it possible to analyze the influence of platinum vapors on the formation of carbon nanomaterials (CNM). The non-uniform distribution of catalyst atoms (platinum) in the products of electrochemical synthesis in a gas medium using FGDG-7 graphite was investigated. During the analysis, it was found that platinum is in the state of the face-centered cubic (FCC) lattice and is distributed in the synthesis products as follows: the core of the deposit is less than < 0.001 %, the shell of the deposit is less than < 1 %, the wall soot is more than > 1 %. The morphology and composition of the platinum deposit, which has a hexagonal graphite structure with an admixture of a rhombohedral graphite phase, was studied. In the studies, differential thermal analysis in air (TG, DTG, DTA) was carried out, which made it possible to identify the composition of the synthesis products. It is an established fact that the parts of the deposit with platinum are more heat-resistant compared to the deposit components that do not contain Pt. The resulting carbon nanotubes (CNTs) in diameter (5–25 nm) and length (1.5–2 μm) do not differ from those obtained without the participation of platinum, except for some anomalies. When studying the suitability of platinum-containing carbon nanostructures for 3D printing of CJP (ceramic printing) technology, it was found that for the use of platinum-containing carbon black, it is necessary to carry out a preliminary short-term treatment, namely, grinding in special “ball mills” or rubbing through a fine sieve with minimal effort to create uniformity product. Previous studies have shown that such platinum-containing carbon nanostructures can already be used in 3D printing of CJP technology, or to create new composites for 3D printing technologies of FDM, SLA.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134024404","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 undamaged structure and functionality of the skeleton are a prerequisite for ensuring the quality of human life. The introduction of the latest treatment methods and prosthetics in traumatic surgery, oncology, cranial surgery, and dentistry form a demand for biomaterials with functionalized properties. The growth of new bone tissue is a cell-regulated process based on creating a specific bone morphology, which combines the organic matrix and its inorganic content. The inorganic component of human bones and teeth is calcium deficiency hydroxyapatite (cdHA), with a molar ratio of Ca/P ranging from 1.5 to 1.67. The combination of cdHA and natural polymers in the material allows the incorporation of proteins and growth factors into the polymer matrix. It promotes biocompatibility and the growth of new bone tissue. This review considers the critical role of the porosity parameter of biomaterials (BM) in their use for bone regeneration. Porosity is an essential characteristic of BM and guarantees the interaction of the material with cells in bone formation, promoting vascularization and the process of biosorption of synthetic graft when it is replaced by newly formed native bone. At the same time, the degree of porosity should correlate with mechanical stability to maintain the structural integrity of BM in the process of hard tissue regeneration. Processes involving cells and proteins during BM implantation with both high (70–80 %) and low (≤ 45 %) degrees of porosity are considered. Data on existing methods of obtaining BM in porous scaffolds are given. The specified degree of porosity is provided by chemical (cross-linking) and physical (sublimation) methods. The effects of pores of different sizes and shapes on bone formation and vascularization are considered. It is shown that porosity is an influential factor influencing the mechanical properties of scaffolds, in particular, the stiffness of BM - a parameter that affects the proliferation of osteoblasts by regulating cell adhesion in the scaffold structure. The influence of the biopolymer component (Sodium Alginate - AN) on the porosity and swelling of hybrid apatite-biopolymer (HA/AN) composites, in which nanometric needle crystallites represent HA, is analyzed in detail.
{"title":"Physical and chemical factors influencing the porosity of apatite-biopolymer composites","authors":"L. Sukhodub, L. Sukhodub, M. Kumeda","doi":"10.15407/hftp13.03.301","DOIUrl":"https://doi.org/10.15407/hftp13.03.301","url":null,"abstract":"The undamaged structure and functionality of the skeleton are a prerequisite for ensuring the quality of human life. The introduction of the latest treatment methods and prosthetics in traumatic surgery, oncology, cranial surgery, and dentistry form a demand for biomaterials with functionalized properties. The growth of new bone tissue is a cell-regulated process based on creating a specific bone morphology, which combines the organic matrix and its inorganic content. The inorganic component of human bones and teeth is calcium deficiency hydroxyapatite (cdHA), with a molar ratio of Ca/P ranging from 1.5 to 1.67. The combination of cdHA and natural polymers in the material allows the incorporation of proteins and growth factors into the polymer matrix. It promotes biocompatibility and the growth of new bone tissue. This review considers the critical role of the porosity parameter of biomaterials (BM) in their use for bone regeneration. Porosity is an essential characteristic of BM and guarantees the interaction of the material with cells in bone formation, promoting vascularization and the process of biosorption of synthetic graft when it is replaced by newly formed native bone. At the same time, the degree of porosity should correlate with mechanical stability to maintain the structural integrity of BM in the process of hard tissue regeneration. Processes involving cells and proteins during BM implantation with both high (70–80 %) and low (≤ 45 %) degrees of porosity are considered. Data on existing methods of obtaining BM in porous scaffolds are given. The specified degree of porosity is provided by chemical (cross-linking) and physical (sublimation) methods. The effects of pores of different sizes and shapes on bone formation and vascularization are considered. It is shown that porosity is an influential factor influencing the mechanical properties of scaffolds, in particular, the stiffness of BM - a parameter that affects the proliferation of osteoblasts by regulating cell adhesion in the scaffold structure. The influence of the biopolymer component (Sodium Alginate - AN) on the porosity and swelling of hybrid apatite-biopolymer (HA/AN) composites, in which nanometric needle crystallites represent HA, is analyzed in detail.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125145621","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}
N. Sych, V. M. Vikarchuk, L. I. Kotyns’ka, N. N. Tsyba, L. Kupchyk, A. O. Lysenko
The paper considers an approach to the processing of waste of agro-industrial raw materials due to chemical activation. To obtain a sorption material, waste was used, which is the shell of Juglansregia walnuts. The aim of the work was to develop adsorbents from walnut shells with a large proportion of mesopores, to determine the parameters of the porous structure and to study their adsorption capability to absorb egg albumin as a marker of medium molecular toxins of a protein nature. Activated carbon samples with a high mesopore content (550 m2/g) were obtained by combined activation of the feedstock. The sorption of one of the obtained samples and, for comparison, the medical product SORBEX was studied by the spectrophotometric method, and its effectiveness was proved in the absorption of egg albumin from aqueous solutions. The significant capability of the obtained sample to sorb protein (35–38 mg/g) was shown, it has been assumed that in the process of sorption, macromolecules are concentrated near the inlets into the pores of the adsorbent. It can be stated that the adsorption of albumin increases in proportion to the increase in the specific surface area of the mesopore. Using the obtained sorption isotherms, the parameters of adsorption processes were calculated. Adsorption isotherms were calculated using the Langmuir and Freundlich equations. It is shown that the maximum adsorption values calculated using the Langmuir equation are in good agreement with the experimental data.
{"title":"Chemical activation of walnut shells with calcium acetate. Mesoporous structure and adsorption efficiency of ovalbumin","authors":"N. Sych, V. M. Vikarchuk, L. I. Kotyns’ka, N. N. Tsyba, L. Kupchyk, A. O. Lysenko","doi":"10.15407/hftp13.03.330","DOIUrl":"https://doi.org/10.15407/hftp13.03.330","url":null,"abstract":"The paper considers an approach to the processing of waste of agro-industrial raw materials due to chemical activation. To obtain a sorption material, waste was used, which is the shell of Juglansregia walnuts. The aim of the work was to develop adsorbents from walnut shells with a large proportion of mesopores, to determine the parameters of the porous structure and to study their adsorption capability to absorb egg albumin as a marker of medium molecular toxins of a protein nature. Activated carbon samples with a high mesopore content (550 m2/g) were obtained by combined activation of the feedstock. The sorption of one of the obtained samples and, for comparison, the medical product SORBEX was studied by the spectrophotometric method, and its effectiveness was proved in the absorption of egg albumin from aqueous solutions. The significant capability of the obtained sample to sorb protein (35–38 mg/g) was shown, it has been assumed that in the process of sorption, macromolecules are concentrated near the inlets into the pores of the adsorbent. It can be stated that the adsorption of albumin increases in proportion to the increase in the specific surface area of the mesopore. Using the obtained sorption isotherms, the parameters of adsorption processes were calculated. Adsorption isotherms were calculated using the Langmuir and Freundlich equations. It is shown that the maximum adsorption values calculated using the Langmuir equation are in good agreement with the experimental data.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124310664","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 purpose of the work is synthesis of new organomineral composites by in situ immobilization and adsorption of poly[8-methacroyloxy-quinoline] on the surface of vermiculite and study of sorption properties of cations Cu(II), Pb(II) and Fe(III). In situ immobilization of poly [8-oxyquinolinemethacrylate] on the surface of vermiculite was carried out by initiated radical polymerization of 8 oxyquinoline methacrylate using 2,2′-azobisisobutyronitrile (AIBN) as a dinitrile initiator in the presence of vermiculite. To obtain the composite by adsorption of poly[8-oxyquinolinemethacrylate] on the surface of vermiculite, the polymer was synthesized in advance, then dissolved in tetrahydrofuran and adsorbed on vermiculite. The fact of immobilization of poly[8-oxyquinolinemethacrylate] on the surface of vermiculite was confirmed by comparative analysis of the IR spectra of the source mineral and relative composites. The regularities of thermal decomposition of immobilized polymer were studied by thermogravimetric analysis combined with mass spectrometry. Using the results of low-temperature adsorption-desorption of nitrogen and scanning electron microscopy, changes in the morphology of the vermiculite surface after immobilization of poly[8-oxyquinolinemethacrylate] by the selected methods are shown. The sorption characteristics of the synthesized composites with respect to Cu(II), Pb(II) and Fe(III) ions were examined in static mode. The polymer with oxyquinoline groups immobilized on the surface of vermiculite showed sorption activity against those metal ions with which 8-oxyquinoline forms stable complexes, the sorption capacity relative to cations Cu(II) is doubled after in situ immobilization of poly [8-oxyquinoline methacrylate] on the surface of vermiculite and increases almost 3 times after adsorption of this polymer. For Pb(ІІ) ions this effect is lower: after in situ immobilization of [8-methacroyloxy-quinoline] sorption capacity increases by one-third and as the result, the increasing of adsorption of this polymer is insignificant and is within the experimental accuracy.
{"title":"Comparison of sorption properties towards toxic metal ions of organomineral composites based on vermiculite with in situ immobilized and adsorbed poly [8-oxyquinoline methacrylate]","authors":"E. Yanovska, I. Savchenko, O. Kychkyruk","doi":"10.15407/hftp13.03.289","DOIUrl":"https://doi.org/10.15407/hftp13.03.289","url":null,"abstract":"The purpose of the work is synthesis of new organomineral composites by in situ immobilization and adsorption of poly[8-methacroyloxy-quinoline] on the surface of vermiculite and study of sorption properties of cations Cu(II), Pb(II) and Fe(III). In situ immobilization of poly [8-oxyquinolinemethacrylate] on the surface of vermiculite was carried out by initiated radical polymerization of 8 oxyquinoline methacrylate using 2,2′-azobisisobutyronitrile (AIBN) as a dinitrile initiator in the presence of vermiculite. To obtain the composite by adsorption of poly[8-oxyquinolinemethacrylate] on the surface of vermiculite, the polymer was synthesized in advance, then dissolved in tetrahydrofuran and adsorbed on vermiculite. The fact of immobilization of poly[8-oxyquinolinemethacrylate] on the surface of vermiculite was confirmed by comparative analysis of the IR spectra of the source mineral and relative composites. The regularities of thermal decomposition of immobilized polymer were studied by thermogravimetric analysis combined with mass spectrometry. Using the results of low-temperature adsorption-desorption of nitrogen and scanning electron microscopy, changes in the morphology of the vermiculite surface after immobilization of poly[8-oxyquinolinemethacrylate] by the selected methods are shown. The sorption characteristics of the synthesized composites with respect to Cu(II), Pb(II) and Fe(III) ions were examined in static mode. The polymer with oxyquinoline groups immobilized on the surface of vermiculite showed sorption activity against those metal ions with which 8-oxyquinoline forms stable complexes, the sorption capacity relative to cations Cu(II) is doubled after in situ immobilization of poly [8-oxyquinoline methacrylate] on the surface of vermiculite and increases almost 3 times after adsorption of this polymer. For Pb(ІІ) ions this effect is lower: after in situ immobilization of [8-methacroyloxy-quinoline] sorption capacity increases by one-third and as the result, the increasing of adsorption of this polymer is insignificant and is within the experimental accuracy.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133345163","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}
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