The use of wound dressings is gaining more and more popularity, especially in the field of tactical and military medicine. Developing wound dressings capable of facilitating wound treatment and reducing healing time is one of the challenges of modern science. So, sodium alginate (Alg) is a good candidate for the development of wound dressings due to its bio- and hemocompatibility and biodegradability. However, Alg has its shortcomings, which can be dispatched by modification. The purpose of this work was to investigate the effect of Alg modification on the kinetics of ethonium release from crosslinked with Ca2+ ions samples. For this purpose, a method of Alg modifying with octane-1-amine was developed without the use of organic solvents and with the use of 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDCl) as an initiator. The optimal parameters of alginate modification process were defined as 60 °С temperature and 24 hours duration. Physicochemical methods confirmed the success of the modification. Films based on the alginate modified with octane-1-amine (AlgM) were obtained using a calcium chloride solution as a crosslinker. The kinetics of swelling was studied and we found that the degree of swelling of the sample based on AlgM after 10 minutes is twice as large (α = 0.71) as for Alg (α = 0.37), which indicates a faster release of drugs. It has been found that the kinetics of release of ethonium depends not only on the kinetics of swelling but also on the chemical nature of the drug. The ethonium was immobilised in alginate films as a model of bactericidal drug. The kinetics of ethonium release was studied at different pH values corresponding to the pH of healthy skin (5.5), open wounds (7.2) and inflamed wounds (8.2). It was found that the release of ethonium from the sample based on AlgM is more pH-sensitive and prolonged, compared to the sample based on Alg. This effect is explained by the appearance of an additional mechanism of retention of ethonium by AlgM due to hydrophobic-hydrophobic interactions in the films. The prolonged release properties observed in the drug-loaded samples make them promising candidates for the development of targeted drug delivery systems and wound dressings, which are particularly relevant for the treatment of chronic and burn wounds. Future research will focus on optimizing the crosslinking method and exploring potential applications of modified alginate-based materials in biomedical sciences.
{"title":"Hydrogel films based on sodium alginate modified with octane-1-amine: enhanced pore formation and potential applications in drug delivery systems","authors":"A. V. Sikach, V. V. Konovalova, I. S. Kolesnyk","doi":"10.15407/hftp15.01.043","DOIUrl":"https://doi.org/10.15407/hftp15.01.043","url":null,"abstract":"The use of wound dressings is gaining more and more popularity, especially in the field of tactical and military medicine. Developing wound dressings capable of facilitating wound treatment and reducing healing time is one of the challenges of modern science. So, sodium alginate (Alg) is a good candidate for the development of wound dressings due to its bio- and hemocompatibility and biodegradability. However, Alg has its shortcomings, which can be dispatched by modification. The purpose of this work was to investigate the effect of Alg modification on the kinetics of ethonium release from crosslinked with Ca2+ ions samples. For this purpose, a method of Alg modifying with octane-1-amine was developed without the use of organic solvents and with the use of 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDCl) as an initiator. The optimal parameters of alginate modification process were defined as 60 °С temperature and 24 hours duration. Physicochemical methods confirmed the success of the modification. Films based on the alginate modified with octane-1-amine (AlgM) were obtained using a calcium chloride solution as a crosslinker. The kinetics of swelling was studied and we found that the degree of swelling of the sample based on AlgM after 10 minutes is twice as large (α = 0.71) as for Alg (α = 0.37), which indicates a faster release of drugs. It has been found that the kinetics of release of ethonium depends not only on the kinetics of swelling but also on the chemical nature of the drug. The ethonium was immobilised in alginate films as a model of bactericidal drug. The kinetics of ethonium release was studied at different pH values corresponding to the pH of healthy skin (5.5), open wounds (7.2) and inflamed wounds (8.2). It was found that the release of ethonium from the sample based on AlgM is more pH-sensitive and prolonged, compared to the sample based on Alg. This effect is explained by the appearance of an additional mechanism of retention of ethonium by AlgM due to hydrophobic-hydrophobic interactions in the films. The prolonged release properties observed in the drug-loaded samples make them promising candidates for the development of targeted drug delivery systems and wound dressings, which are particularly relevant for the treatment of chronic and burn wounds. Future research will focus on optimizing the crosslinking method and exploring potential applications of modified alginate-based materials in biomedical sciences.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"27 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140362296","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}
Y. M. Samchenko, S. Dybkova, L. Reznichenko, L. Kernosenko, T. Gruzina, T. P. Poltoratska, O. B. Liutko, K. Vitrak, V. I. Podolska, P. V. Vorotytskyi
Artificial implants are a favorable environment for bacterial adhesion and subsequent biofilm formation, thereby accelerating the development of infection in the area of implant incorporation. Despite significant progress in the development of various endoprostheses over the past decades, bacterial periprosthetic infection is one of the main factors leading to complications in their use, prolongation of rehabilitation, and significant economic losses. The present work is devoted to the creation of hybrid hydrogel nanocomposites with complex antimicrobial action for endoprosthetics in the maxillofacial region and for filling postoperative cavities (primarily after tumor removal). These nanocomposites were created on the basis of pre-synthesized spongy polyvinylformal with encapsulated gold nanoparticles, the pore space of which was partially filled with pH-sensitive hydrogels based on acrylic acid (or copolymers based on acrylamide and acrylic acid) with sorbed Albucid. The structure of the synthesized hybrid hydrogel materials was confirmed by IR spectroscopy. Studies of the kinetics of hydrogel swelling in buffer solutions with different pH values have shown that the sample filled with a copolymer of acrylamide and acrylic acid with their ratio 95:5 has the optimal properties for preserving the geometric dimensions of the material for endoprosthetics, while in the case of incorporation of 100 % acrylic acid, the degree of swelling of the material (and, respectively, its dimensions) can vary significantly with a change of рН. Antimicrobial effect of the developed hybrid hydrogel materials was investigated using the following bacterial cultures: Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29213, Staphylococcus aureus ATCC 25923, and Pseudomonas aeruginosa ATCC 27853. The antibacterial effect of polyvinylformal-based composites with incorporated gold nanoparticles that were saturated with Albucid on all test microorganisms was demonstrated (growth inhibition zones ranged from 15 to 35 mm), which will prevent microbial contamination of the developed hybrid hydrogel material when it is used in endoprosthesis.
{"title":"Synthesis and study on antimicrobial properties of hydrogel materials for maxillo-facial surgery","authors":"Y. M. Samchenko, S. Dybkova, L. Reznichenko, L. Kernosenko, T. Gruzina, T. P. Poltoratska, O. B. Liutko, K. Vitrak, V. I. Podolska, P. V. Vorotytskyi","doi":"10.15407/hftp15.01.110","DOIUrl":"https://doi.org/10.15407/hftp15.01.110","url":null,"abstract":"Artificial implants are a favorable environment for bacterial adhesion and subsequent biofilm formation, thereby accelerating the development of infection in the area of implant incorporation. Despite significant progress in the development of various endoprostheses over the past decades, bacterial periprosthetic infection is one of the main factors leading to complications in their use, prolongation of rehabilitation, and significant economic losses. The present work is devoted to the creation of hybrid hydrogel nanocomposites with complex antimicrobial action for endoprosthetics in the maxillofacial region and for filling postoperative cavities (primarily after tumor removal). These nanocomposites were created on the basis of pre-synthesized spongy polyvinylformal with encapsulated gold nanoparticles, the pore space of which was partially filled with pH-sensitive hydrogels based on acrylic acid (or copolymers based on acrylamide and acrylic acid) with sorbed Albucid. The structure of the synthesized hybrid hydrogel materials was confirmed by IR spectroscopy. Studies of the kinetics of hydrogel swelling in buffer solutions with different pH values have shown that the sample filled with a copolymer of acrylamide and acrylic acid with their ratio 95:5 has the optimal properties for preserving the geometric dimensions of the material for endoprosthetics, while in the case of incorporation of 100 % acrylic acid, the degree of swelling of the material (and, respectively, its dimensions) can vary significantly with a change of рН. Antimicrobial effect of the developed hybrid hydrogel materials was investigated using the following bacterial cultures: Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29213, Staphylococcus aureus ATCC 25923, and Pseudomonas aeruginosa ATCC 27853. The antibacterial effect of polyvinylformal-based composites with incorporated gold nanoparticles that were saturated with Albucid on all test microorganisms was demonstrated (growth inhibition zones ranged from 15 to 35 mm), which will prevent microbial contamination of the developed hybrid hydrogel material when it is used in endoprosthesis.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"25 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140364710","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. Roik, I. Trofymchuk, L. O. Belyakova, O. I. Oranska
Silicas of MCM-41‑type with reactive functional groups are widely used as starting substrates in large variety of post‑synthetic chemical modification pathways. Therefore, variation of their structural characteristics in the process of templated sol‑gel synthesis or post-synthetic treatment is of great importance. The aim of this work was to elucidate the influence of template agent selection on structural features of MCM-41‑type materials with surface silanol and 3‑chloropropyl groups. For this purpose, template-assisted sol-gel condensation of structure forming silanes (tetraethyl orthosilicate and 3‑chloropropyltriethoxysilane) was carried out in the presence of decyltrimethylammonium bromide as structure-directing agent. The capability of cyclic oligosaccharide (β-cyclodextrin) to interact with surfactant micelles in the process of hydrothermal sol-gel synthesis and to influence the formation of mesoporous structure of silica materials was studied. The IR spectroscopy was applied to carry out control under the complete removal of template moieties from pores by extraction procedure and to confirm introduction of 3‑chloropropyl groups into the surface layer of synthesized silicas. Arrangement of mesoscale pores and structural parameters were estimated from the results of X‑ray diffraction and low-temperature adsorption-desorption of nitrogen. It has been found that β‑cyclodextrin as component of hybrid template has positive effect on porous structure of 3-chloropropyl-functionalized MCM-41-type silica causing increase of surface area accompanied with preservation of pore ordering. Moreover, both ionic surfactant and oligosaccharide components of hybrid template act as porogens during sol-gel condensation of structure forming silanes enable to prepare silica materials with micro-mesoporosity. Proposed approach can be useful in synthesis of MCM‑41‑type silicas with surface linker groups and controlled structural characteristics (pore size, geometry and ordering), which have great potential as substrates in design of sophisticated materials.
{"title":"Hybrid template directed hydrothermal synthesis of MCM-41 silicas with surface silanol and 3-chloropropyl groups","authors":"N. Roik, I. Trofymchuk, L. O. Belyakova, O. I. Oranska","doi":"10.15407/hftp14.04.464","DOIUrl":"https://doi.org/10.15407/hftp14.04.464","url":null,"abstract":"Silicas of MCM-41‑type with reactive functional groups are widely used as starting substrates in large variety of post‑synthetic chemical modification pathways. Therefore, variation of their structural characteristics in the process of templated sol‑gel synthesis or post-synthetic treatment is of great importance. The aim of this work was to elucidate the influence of template agent selection on structural features of MCM-41‑type materials with surface silanol and 3‑chloropropyl groups. For this purpose, template-assisted sol-gel condensation of structure forming silanes (tetraethyl orthosilicate and 3‑chloropropyltriethoxysilane) was carried out in the presence of decyltrimethylammonium bromide as structure-directing agent. The capability of cyclic oligosaccharide (β-cyclodextrin) to interact with surfactant micelles in the process of hydrothermal sol-gel synthesis and to influence the formation of mesoporous structure of silica materials was studied. The IR spectroscopy was applied to carry out control under the complete removal of template moieties from pores by extraction procedure and to confirm introduction of 3‑chloropropyl groups into the surface layer of synthesized silicas. Arrangement of mesoscale pores and structural parameters were estimated from the results of X‑ray diffraction and low-temperature adsorption-desorption of nitrogen. It has been found that β‑cyclodextrin as component of hybrid template has positive effect on porous structure of 3-chloropropyl-functionalized MCM-41-type silica causing increase of surface area accompanied with preservation of pore ordering. Moreover, both ionic surfactant and oligosaccharide components of hybrid template act as porogens during sol-gel condensation of structure forming silanes enable to prepare silica materials with micro-mesoporosity. Proposed approach can be useful in synthesis of MCM‑41‑type silicas with surface linker groups and controlled structural characteristics (pore size, geometry and ordering), which have great potential as substrates in design of sophisticated materials.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":" 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139139069","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. Fesenko, I. Laguta, O. Stavinskaya, P. Kuzema, V. M. Anishchenko, O. I. Oranska, R. V. Ivannikov, O. A. Diyuk, I. O. Skorochod
The aim of this work was to synthesize cerium oxide nanoparticles (CeO2-NPs) using the Magnolia kobus leaves extract, to determine the composition of the extract and the participation of its components in the synthesis of NPs, to study the morphology and structure of the obtained NPs, to investigate their antibacterial activity. The composition of the plant extract and involving of its components in green synthesis of CeO2-NPs was studied by high-performance liquid chromatography (HPLC) and matrix-assisted laser/desorption ionization mass spectrometry (MALDI MS). It has been shown that the extract contained phenolic compounds (derivatives of simple phenols, flavonols, hydroxybenzoic and hydroxycinnamic acids, lignans, coumarins), as well as carotenoids, chlorophylls, terpenoids and sterols. The composition of the liquid phase from the reaction mixture (reaction liquid) after the NPs formation was studied to determine the components of the extract involved in the synthesis of CeO2-NPs. According to the results of HPLC and MALDI MS studies, significant differences were found in the composition of the plant extract and the reaction liquid: hydroxybenzoic acids, flavonoids and terpenoids disappeared or their concentration was significantly decreased, the content of lignans changed to a lesser extent, and it was observed the appearance of hydrophilic low-molecular compounds probably formed as a result of synthesis and stabilization of NPs. Synthesized CeO2-NPs were characterized by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). According to SEM and XRD, CeO2-NPs had a crystalline structure and were of spherical shape; the average size of the crystallites was ~ 20 nm, and the diameter of the primary particles was 50 ± 10 nm. It has been found that hydroxybenzoic acids, flavonoids and terpenoids are active participants in the green synthesis of CeO2-NPs in the presence of Magnolia kobus leaves extract, while lignans (fargesin/kobusin and eudesmin) are involved in less extend in the reduction/stabilization of CeO2-NPs. The synthesized particles possess antibacterial properties and can be used in the preparation of materials for medical and biological purposes.
{"title":"Green synthesis of antibacterial cerium oxide nanoparticles using Magnolia kobus leaves extract","authors":"T. Fesenko, I. Laguta, O. Stavinskaya, P. Kuzema, V. M. Anishchenko, O. I. Oranska, R. V. Ivannikov, O. A. Diyuk, I. O. Skorochod","doi":"10.15407/hftp14.04.546","DOIUrl":"https://doi.org/10.15407/hftp14.04.546","url":null,"abstract":"The aim of this work was to synthesize cerium oxide nanoparticles (CeO2-NPs) using the Magnolia kobus leaves extract, to determine the composition of the extract and the participation of its components in the synthesis of NPs, to study the morphology and structure of the obtained NPs, to investigate their antibacterial activity. The composition of the plant extract and involving of its components in green synthesis of CeO2-NPs was studied by high-performance liquid chromatography (HPLC) and matrix-assisted laser/desorption ionization mass spectrometry (MALDI MS). It has been shown that the extract contained phenolic compounds (derivatives of simple phenols, flavonols, hydroxybenzoic and hydroxycinnamic acids, lignans, coumarins), as well as carotenoids, chlorophylls, terpenoids and sterols. The composition of the liquid phase from the reaction mixture (reaction liquid) after the NPs formation was studied to determine the components of the extract involved in the synthesis of CeO2-NPs. According to the results of HPLC and MALDI MS studies, significant differences were found in the composition of the plant extract and the reaction liquid: hydroxybenzoic acids, flavonoids and terpenoids disappeared or their concentration was significantly decreased, the content of lignans changed to a lesser extent, and it was observed the appearance of hydrophilic low-molecular compounds probably formed as a result of synthesis and stabilization of NPs. Synthesized CeO2-NPs were characterized by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). According to SEM and XRD, CeO2-NPs had a crystalline structure and were of spherical shape; the average size of the crystallites was ~ 20 nm, and the diameter of the primary particles was 50 ± 10 nm. It has been found that hydroxybenzoic acids, flavonoids and terpenoids are active participants in the green synthesis of CeO2-NPs in the presence of Magnolia kobus leaves extract, while lignans (fargesin/kobusin and eudesmin) are involved in less extend in the reduction/stabilization of CeO2-NPs. The synthesized particles possess antibacterial properties and can be used in the preparation of materials for medical and biological purposes.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":" 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139141890","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. Tsitsishvili, N. Dolaberidze, M. Nijaradze, N. Mirdzveli, Z. Amiridze, B. Khutsishvili
Acid treatment of natural zeolites is considered to be an effective method of “improving” their structure and properties, among which thermal stability occupies a special place, especially for catalytic applications of zeolites. The influence of hydrochloric acid solutions with concentrations up to 2 mol/L and calcination at temperatures up to 1100 °C on the structure and properties of heulandite-containing tuff from the Georgian Dzegvi-Tedzami deposit, selected for the creation of new bactericidal zeolite filter materials for purification and desinfection of water from various sources, was studied by the X-ray energy dispersion spectra, diffraction patterns and thermal analysis, as well as by adsorption of water, benzene and nitrogen methods. It has been found that an acidic environment leads to significant dealumination (Si/Al molar ratio increases from 3.6 to 9.5) and decationization (total charge of metal ions per Al atom decreases from 1 to 0.68) of the sample; solutions of hydrochloric acid do not lead to amorphization of the zeolite microporous crystal structure, but gradually dissolve it. As a result of acid treatment, there is also a sharp increase in the volume of micropores available for large molecules (from ≈ 7 to 80–90 mm3/g) and surface area (from ≈ 13 to 120–175 m2/g), as well as changes in the mesoporous system, leading to the prevalence of pores with a diameter of up to 4 nm. Heulandite heating leads to stepwise dehydration proceeding up to ≈ 800 °C, amorphization starting at ≈ 250 °C, and structural changes: the transition to methastable heulandite B phase at ≈ 340 °C is not fixed, but at ≈ 500 °C wairakite (Ca(Al2Si4O12)·2H2O) is formed, at temperatures above ≈ 1000 °C, amorphous aluminosilicate contains crystalline inclusions of cristobalite (polymorph of SiO2), α-quartz, albite (Na(AlSi3O8), hematite (Fe2O3) and magnetite (FeO·Fe2O3); heating-induced changes in micro- and mesopore systems are insignificant. It is also shown that heat treatment increases the acid resistance of heulandite, which is expressed in a decrease in the degree of dealumination after acid treatment of calcined samples. Thus, acid and heat treatment of heulandite make it possible to obtain materials with different sorption and ion-exchange properties.
{"title":"Acid and thermal treatment of natural heulandite","authors":"V. Tsitsishvili, N. Dolaberidze, M. Nijaradze, N. Mirdzveli, Z. Amiridze, B. Khutsishvili","doi":"10.15407/hftp14.04.519","DOIUrl":"https://doi.org/10.15407/hftp14.04.519","url":null,"abstract":"Acid treatment of natural zeolites is considered to be an effective method of “improving” their structure and properties, among which thermal stability occupies a special place, especially for catalytic applications of zeolites. The influence of hydrochloric acid solutions with concentrations up to 2 mol/L and calcination at temperatures up to 1100 °C on the structure and properties of heulandite-containing tuff from the Georgian Dzegvi-Tedzami deposit, selected for the creation of new bactericidal zeolite filter materials for purification and desinfection of water from various sources, was studied by the X-ray energy dispersion spectra, diffraction patterns and thermal analysis, as well as by adsorption of water, benzene and nitrogen methods. It has been found that an acidic environment leads to significant dealumination (Si/Al molar ratio increases from 3.6 to 9.5) and decationization (total charge of metal ions per Al atom decreases from 1 to 0.68) of the sample; solutions of hydrochloric acid do not lead to amorphization of the zeolite microporous crystal structure, but gradually dissolve it. As a result of acid treatment, there is also a sharp increase in the volume of micropores available for large molecules (from ≈ 7 to 80–90 mm3/g) and surface area (from ≈ 13 to 120–175 m2/g), as well as changes in the mesoporous system, leading to the prevalence of pores with a diameter of up to 4 nm. Heulandite heating leads to stepwise dehydration proceeding up to ≈ 800 °C, amorphization starting at ≈ 250 °C, and structural changes: the transition to methastable heulandite B phase at ≈ 340 °C is not fixed, but at ≈ 500 °C wairakite (Ca(Al2Si4O12)·2H2O) is formed, at temperatures above ≈ 1000 °C, amorphous aluminosilicate contains crystalline inclusions of cristobalite (polymorph of SiO2), α-quartz, albite (Na(AlSi3O8), hematite (Fe2O3) and magnetite (FeO·Fe2O3); heating-induced changes in micro- and mesopore systems are insignificant. It is also shown that heat treatment increases the acid resistance of heulandite, which is expressed in a decrease in the degree of dealumination after acid treatment of calcined samples. Thus, acid and heat treatment of heulandite make it possible to obtain materials with different sorption and ion-exchange properties.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":" 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139137537","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}
Features of interfacial adsorbate/adsorbent phenomena depend on several factors: particulate morphology, texture, and structure of adsorbents, molecular weight, shape, and polarity of adsorbates; as well as prehistory of adsorbents pretreated under different conditions. All these factors could affect the efficiency of practical applications of not only adsorbents but also polymer fillers, carriers, catalysts, etc. Interactions of nonpolar nitrogen, hexane, benzene, weakly polar acetonitrile, and polar diethylamine, triethylamine, and water with individual (silica, alumina), binary (silica/alumina (SA)) and ternary (alumina/silica/titania, AST) nanooxides were studied using experimental and theoretical methods to elucidate the influence of the morphological and textural characteristics and surface composition of the materials on the adsorption phenomena. The specific surface area SX / ratio (X is an adsorbate) changes from 0.7 for hexane adsorbed onto amorphous silica/alumina SA8 with 8 wt. % Al2O3 (degassed at 200 °C) to 1.9 for acetonitrile adsorbed onto pure fumed alumina (treated at 900 °C). These changes are relatively large because of variations in orientation, lateral interactions, and adsorption compressing of organic molecules interacting with surfaces characterized by certain set and amounts of various active sites, as well as due to changes in the accessibility of pore surface for probe molecules of different sizes. Larger SX / > 1 values are observed for complex fumed oxides with larger primary nanoparticles, greater surface roughness, hydrophilicity, and Brønsted and Lewis acidity of a surface. Both polar and nonpolar adsorbates can change the morphology and texture of aggregates of oxide nanoparticles, e.g., swelling of structures, compacted during various pretreatments, upon the adsorption of liquids. The studied effects should be considered upon practical applications of adsorbents, especially “soft” fumed oxides.
{"title":"Adsorption of various compounds onto nanooxides unmodified and differently pretreated","authors":"V. Gun'ko, O. K. Matkovsky","doi":"10.15407/hftp14.04.474","DOIUrl":"https://doi.org/10.15407/hftp14.04.474","url":null,"abstract":"Features of interfacial adsorbate/adsorbent phenomena depend on several factors: particulate morphology, texture, and structure of adsorbents, molecular weight, shape, and polarity of adsorbates; as well as prehistory of adsorbents pretreated under different conditions. All these factors could affect the efficiency of practical applications of not only adsorbents but also polymer fillers, carriers, catalysts, etc. Interactions of nonpolar nitrogen, hexane, benzene, weakly polar acetonitrile, and polar diethylamine, triethylamine, and water with individual (silica, alumina), binary (silica/alumina (SA)) and ternary (alumina/silica/titania, AST) nanooxides were studied using experimental and theoretical methods to elucidate the influence of the morphological and textural characteristics and surface composition of the materials on the adsorption phenomena. The specific surface area SX / ratio (X is an adsorbate) changes from 0.7 for hexane adsorbed onto amorphous silica/alumina SA8 with 8 wt. % Al2O3 (degassed at 200 °C) to 1.9 for acetonitrile adsorbed onto pure fumed alumina (treated at 900 °C). These changes are relatively large because of variations in orientation, lateral interactions, and adsorption compressing of organic molecules interacting with surfaces characterized by certain set and amounts of various active sites, as well as due to changes in the accessibility of pore surface for probe molecules of different sizes. Larger SX / > 1 values are observed for complex fumed oxides with larger primary nanoparticles, greater surface roughness, hydrophilicity, and Brønsted and Lewis acidity of a surface. Both polar and nonpolar adsorbates can change the morphology and texture of aggregates of oxide nanoparticles, e.g., swelling of structures, compacted during various pretreatments, upon the adsorption of liquids. The studied effects should be considered upon practical applications of adsorbents, especially “soft” fumed oxides.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":" 37","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139138321","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}
When metal nanoparticles (MNPs) are illuminated with a monochromatic laser wave, the frequency of which is far from the plasmon frequency (the frequency of plasmon resonances), under certain conditions (depending on the frequency of the wave, its polarization, the size and shape of the MNPs), absorption of light by MNPs can be dominated by magnetic absorption (absorption caused by the magnetic component of the electromagnetic field of the light (laser) wave). This work is focused on studying the features of absorption caused by the influence of the magnetic component of laser radiation. This issue is rather poorly studied for MNPs of non-spherical shape. Therefore, how the shape of the particle manifests itself in its absorption of laser radiation (laser pulses) is one of the goals of our research. In this work, we will study the features of magnetic absorption of light (laser radiation) depending on the shape of the particles. In this paper, we will investigate the influence of spheroidal MNPs on this process. Calculations will be carried out using the kinetic equation method, because we will consider the case when the size of the MNP is smaller than the length of free path of the electron in the MNP. Note that the kinetic approach makes it possible to obtain correct results for the case when the size of the particle is greater than the length of the free path. For non-spherical MNPs, we have developed a theory that makes it possible to calculate the energy of magnetic absorption by a particle when it is irradiated with laser pulses. The dependence of magnetic absorption on the ratio of the radii of curvature of spheroidal MNPs and the vector of the magnetic field of an electromagnetic (laser) wave was constructed and theoretically investigated. An interesting result is the absorption of energy by a spheroidal MNP as its disco similarity increases. We now use to estimate the relative contributions of electric We and magnetic Wm absorption to the total absorption. For example, let us take a gold MNP’s, then ωp ≈ 5·1015 s–1, ν ≈ 1013 s–1, R = 3·10–6 sm, ω ≈ 2·1014 s–1 (carbon dioxide laser), ε' ≈ –600, ε'' ≈ 30 we received the next ratio We/Wm ≈ 2. We can see that for the given set of parameters magnetic absorption is twice as large as electric. Obviously, for different parameters of the particle and a different frequency range electric absorption can be either larger or smaller than magnetic absorption. Hence, when studying the dependence of optical absorption by MNP’s on particle form, we must allow for both electric and magnetic absorption. For an asymmetric MNP’s (for example ellipsoidal particles), apart from everything else, the ratio of the electric and magnetic contributions to absorption (as fixed frequency) is strongly dependent on the degree of particle asymmetric and wave polarization.
{"title":"Kinetic theory of magnetic absorption of laser irradiation by nanoparticles","authors":"O. Semchuk, O. Havryliuk, A. Biliuk","doi":"10.15407/hftp14.04.504","DOIUrl":"https://doi.org/10.15407/hftp14.04.504","url":null,"abstract":"When metal nanoparticles (MNPs) are illuminated with a monochromatic laser wave, the frequency of which is far from the plasmon frequency (the frequency of plasmon resonances), under certain conditions (depending on the frequency of the wave, its polarization, the size and shape of the MNPs), absorption of light by MNPs can be dominated by magnetic absorption (absorption caused by the magnetic component of the electromagnetic field of the light (laser) wave). This work is focused on studying the features of absorption caused by the influence of the magnetic component of laser radiation. This issue is rather poorly studied for MNPs of non-spherical shape. Therefore, how the shape of the particle manifests itself in its absorption of laser radiation (laser pulses) is one of the goals of our research. In this work, we will study the features of magnetic absorption of light (laser radiation) depending on the shape of the particles. In this paper, we will investigate the influence of spheroidal MNPs on this process. Calculations will be carried out using the kinetic equation method, because we will consider the case when the size of the MNP is smaller than the length of free path of the electron in the MNP. Note that the kinetic approach makes it possible to obtain correct results for the case when the size of the particle is greater than the length of the free path. For non-spherical MNPs, we have developed a theory that makes it possible to calculate the energy of magnetic absorption by a particle when it is irradiated with laser pulses. The dependence of magnetic absorption on the ratio of the radii of curvature of spheroidal MNPs and the vector of the magnetic field of an electromagnetic (laser) wave was constructed and theoretically investigated. An interesting result is the absorption of energy by a spheroidal MNP as its disco similarity increases. We now use to estimate the relative contributions of electric We and magnetic Wm absorption to the total absorption. For example, let us take a gold MNP’s, then ωp ≈ 5·1015 s–1, ν ≈ 1013 s–1, R = 3·10–6 sm, ω ≈ 2·1014 s–1 (carbon dioxide laser), ε' ≈ –600, ε'' ≈ 30 we received the next ratio We/Wm ≈ 2. We can see that for the given set of parameters magnetic absorption is twice as large as electric. Obviously, for different parameters of the particle and a different frequency range electric absorption can be either larger or smaller than magnetic absorption. Hence, when studying the dependence of optical absorption by MNP’s on particle form, we must allow for both electric and magnetic absorption. For an asymmetric MNP’s (for example ellipsoidal particles), apart from everything else, the ratio of the electric and magnetic contributions to absorption (as fixed frequency) is strongly dependent on the degree of particle asymmetric and wave polarization.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":" 45","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139139727","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}
I. Rubashvili, M. Zautashvili, T. Kordzakhia, K. Ebralidze
The present work is the first case where the adsorptive removal of the most commonly used fluoroquinolone antibiotic - levofloxacin (> 80 % unmetabolized in the urine) from aqueous solution as a model of wastewater treatment plant effluent by natural zeolite – clinoptilolite and its acid-modified form has been investigated under static and dynamic conditions. The effect of the inlet concentration, the flow rate and the pH value of antibiotic influent solution, also, the contact time of system zeolite/antibiotic solution on the adsorption process were examined and evaluated using the Langmuir adsorption model. The adsorption mechanism mainly composed of electrostatic interaction between the zeolite surface and adsorbate - levofloxacin. This study demonstrates and proves that natural clinoptilolite and its acid-modified form could be an efficient, eco-friendly, alternative and competitive adsorbent in terms of cheapness, selectivity and adsorption efficacy for the removal of levofloxacin from wastewaters and implemented in an industrial setting and wastewater treatment plant for purification processes.
{"title":"Adsorption study of fluoroquinolone antibiotic - levofloxacin to evaluate the possibility of its removal from wastewaters using natural zeolite","authors":"I. Rubashvili, M. Zautashvili, T. Kordzakhia, K. Ebralidze","doi":"10.15407/hftp14.04.512","DOIUrl":"https://doi.org/10.15407/hftp14.04.512","url":null,"abstract":"The present work is the first case where the adsorptive removal of the most commonly used fluoroquinolone antibiotic - levofloxacin (> 80 % unmetabolized in the urine) from aqueous solution as a model of wastewater treatment plant effluent by natural zeolite – clinoptilolite and its acid-modified form has been investigated under static and dynamic conditions. The effect of the inlet concentration, the flow rate and the pH value of antibiotic influent solution, also, the contact time of system zeolite/antibiotic solution on the adsorption process were examined and evaluated using the Langmuir adsorption model. The adsorption mechanism mainly composed of electrostatic interaction between the zeolite surface and adsorbate - levofloxacin. This study demonstrates and proves that natural clinoptilolite and its acid-modified form could be an efficient, eco-friendly, alternative and competitive adsorbent in terms of cheapness, selectivity and adsorption efficacy for the removal of levofloxacin from wastewaters and implemented in an industrial setting and wastewater treatment plant for purification processes.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":" 59","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139137894","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 influence of the Nernst diffusion layer thickness on the surface concentrations of electroactive and electroinactive species in a model electrochemical process with a preceding homogeneous first-order chemical reaction under application of a small amplitude alternating current has been investigated. A case of equal diffusion coefficients of species taking part in the preceding chemical reaction in a thin layer attached to a planar electrode is considered. It has been shown that, at low frequencies of an applied alternating current, the surface concentrations of electroactive and electroinactive species increase with increasing the Nernst diffusion layer thickness. At high frequencies, the surface concentrations of both species do not depend on this parameter. However, there is a range of frequencies where the surface concentrations of species can decrease with increasing the Nernst diffusion layer thickness. This range of frequencies can be influenced by a value of the Nernst diffusion layer thickness, the rate constants of chemical reaction, and the diffusion coefficient of species. There exists a phase shift between an alternating current and the surface concentrations of electroactive and electroinactive species that change under application of this current. It is a function of the Nernst diffusion layer thickness, the oscillation diffusion layer thickness, and the reaction layer thickness. In the case of electroactive species, the phase angle can take only a positive value. At low frequencies, it tends to π/2, whereas at high frequencies it decreases to π/4. For the case of electroinactive species, the phase angle can be positive, negative, and equal to zero depending on the value of the Nernst diffusion layer thickness, the rate constants of chemical reaction, and the diffusion coefficient of species. It approaches –π/2 at low frequencies, and at high frequencies it tends to π/4. The both phase angles can have the maxima and the minima. Their values are strongly dependent on the Nernst diffusion layer thickness, the diffusion coefficient of species, the rate constants of chemical reaction.
{"title":"Influence of the Nernst diffusion layer thickness on surface concentration in a model electrochemical process with a preceding chemical reaction","authors":"O. I. Gichan","doi":"10.15407/hftp14.04.453","DOIUrl":"https://doi.org/10.15407/hftp14.04.453","url":null,"abstract":"The influence of the Nernst diffusion layer thickness on the surface concentrations of electroactive and electroinactive species in a model electrochemical process with a preceding homogeneous first-order chemical reaction under application of a small amplitude alternating current has been investigated. A case of equal diffusion coefficients of species taking part in the preceding chemical reaction in a thin layer attached to a planar electrode is considered. It has been shown that, at low frequencies of an applied alternating current, the surface concentrations of electroactive and electroinactive species increase with increasing the Nernst diffusion layer thickness. At high frequencies, the surface concentrations of both species do not depend on this parameter. However, there is a range of frequencies where the surface concentrations of species can decrease with increasing the Nernst diffusion layer thickness. This range of frequencies can be influenced by a value of the Nernst diffusion layer thickness, the rate constants of chemical reaction, and the diffusion coefficient of species. There exists a phase shift between an alternating current and the surface concentrations of electroactive and electroinactive species that change under application of this current. It is a function of the Nernst diffusion layer thickness, the oscillation diffusion layer thickness, and the reaction layer thickness. In the case of electroactive species, the phase angle can take only a positive value. At low frequencies, it tends to π/2, whereas at high frequencies it decreases to π/4. For the case of electroinactive species, the phase angle can be positive, negative, and equal to zero depending on the value of the Nernst diffusion layer thickness, the rate constants of chemical reaction, and the diffusion coefficient of species. It approaches –π/2 at low frequencies, and at high frequencies it tends to π/4. The both phase angles can have the maxima and the minima. Their values are strongly dependent on the Nernst diffusion layer thickness, the diffusion coefficient of species, the rate constants of chemical reaction.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":" 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139138642","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 paper considers the problem of light absorption by a nanocomposite with randomly oriented metal spheroidal particles-inclusions, provided that the volume content of such inclusions is small. Expressions for the frequency dependences of the effective dielectric function and the absorption coefficient of the metal-dielectric nanocomposite are obtained within the effective medium model taking into account the axial symmetry of spheroidal inclusions. The effective relaxation rate of electrons is introduced using the kinetic approach. Numerical calculations are performed for the cases when inclusion particles have the form of elongated and flattened nanospheroids. The results of the calculations indicate the presence of two maxima of the absorption coefficient, which correspond to longitudinal and transverse surface plasmon resonance. The change in the position and magnitude of the maxima of the frequency dependences of the effective dielectric function and the absorption coefficient with varying the size and shape of the spheroidal particles-inclusions is analyzed. It is shown that the greater the difference in the lengths of the semi-axes of the spheroids, the greater the distance between the maxima of the effective dielectric function and the absorption coefficient, and the shape of the curves depends on the eccentricity of spheroidal inclusions. It has been found that the position of the maxima is significantly influenced by the choice of the material of the inclusion particles and the matrix medium, while the height of the maxima is largely influenced by the shape of the nanoparticles, as well as their volume content in the composite medium. It is proved that, dependent on the material of nanoparticles-inclusions, both maxima of the absorption coefficient can be found in the visible part of the spectrum (for Au inclusions) or in the ultraviolet (for Al inclusions). It is also possible that one maximum lies in the visible part of the spectrum, and the other in the ultraviolet, which is the case for inclusions of Pd, Pt, Cu, Ag.
{"title":"Optical absorption of composites with metallic nanosized spheroidal particles","authors":"N. Pavlyshche, A. Korotun, V. P. Kurbatsky","doi":"10.15407/hftp14.04.561","DOIUrl":"https://doi.org/10.15407/hftp14.04.561","url":null,"abstract":"The paper considers the problem of light absorption by a nanocomposite with randomly oriented metal spheroidal particles-inclusions, provided that the volume content of such inclusions is small. Expressions for the frequency dependences of the effective dielectric function and the absorption coefficient of the metal-dielectric nanocomposite are obtained within the effective medium model taking into account the axial symmetry of spheroidal inclusions. The effective relaxation rate of electrons is introduced using the kinetic approach. Numerical calculations are performed for the cases when inclusion particles have the form of elongated and flattened nanospheroids. The results of the calculations indicate the presence of two maxima of the absorption coefficient, which correspond to longitudinal and transverse surface plasmon resonance. The change in the position and magnitude of the maxima of the frequency dependences of the effective dielectric function and the absorption coefficient with varying the size and shape of the spheroidal particles-inclusions is analyzed. It is shown that the greater the difference in the lengths of the semi-axes of the spheroids, the greater the distance between the maxima of the effective dielectric function and the absorption coefficient, and the shape of the curves depends on the eccentricity of spheroidal inclusions. It has been found that the position of the maxima is significantly influenced by the choice of the material of the inclusion particles and the matrix medium, while the height of the maxima is largely influenced by the shape of the nanoparticles, as well as their volume content in the composite medium. It is proved that, dependent on the material of nanoparticles-inclusions, both maxima of the absorption coefficient can be found in the visible part of the spectrum (for Au inclusions) or in the ultraviolet (for Al inclusions). It is also possible that one maximum lies in the visible part of the spectrum, and the other in the ultraviolet, which is the case for inclusions of Pd, Pt, Cu, Ag.","PeriodicalId":296392,"journal":{"name":"Himia, Fizika ta Tehnologia Poverhni","volume":"137 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139140613","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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