Pub Date : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.5
S.G. Borisade, S. Owoeye, I. Oladele, Oladimeji Niyi Iyanuoluwa
In this work, hybrid reinforced epoxy biopolymer composites were developed using natural hydroxyapatite and zinc oxide (nHAp/ZnO). The epoxy was reinforced with varying addition of nHAp and ZnO in the steps of 3, 5 and 7 wt. % respectively using stir casting molding process. The developed composites were immersed in simulated body fluid (SBF) at 37oC to determine their bioactivity. Microstructure evaluation using scanning electron microscopy was also used to assess the morphology of the developed composites before and after in vitro test, respectively.The microstructure evaluation in vitro showed good deposition of white-like layers on the surface indicating good bioactivity reaction with the SBF and affirm that the developed biopolymers will react well with living tissue when used in vivo. However, hybrid sample BP5HB showed better apatite-like layer deposition.
{"title":"BIOACTIVE PROPERTIES AND MORPHOLOGICAL FEATURES OF HYDROXYAPATITE/ZINC OXIDE HYBRID REINFORCED BIO-BASED EPOXY RESIN COMPOSITES FOR DENTISTRY","authors":"S.G. Borisade, S. Owoeye, I. Oladele, Oladimeji Niyi Iyanuoluwa","doi":"10.59957/jctm.v59.i3.2024.5","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.5","url":null,"abstract":"In this work, hybrid reinforced epoxy biopolymer composites were developed using natural hydroxyapatite and zinc oxide (nHAp/ZnO). The epoxy was reinforced with varying addition of nHAp and ZnO in the steps of 3, 5 and 7 wt. % respectively using stir casting molding process. The developed composites were immersed in simulated body fluid (SBF) at 37oC to determine their bioactivity. Microstructure evaluation using scanning electron microscopy was also used to assess the morphology of the developed composites before and after in vitro test, respectively.The microstructure evaluation in vitro showed good deposition of white-like layers on the surface indicating good bioactivity reaction with the SBF and affirm that the developed biopolymers will react well with living tissue when used in vivo. However, hybrid sample BP5HB showed better apatite-like layer deposition.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"118 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141002171","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}
In this work, the interaction of components in the CO(NH2)2 - HOOC - COOH ·NH2C2H4OH - H2O system was studied by visual polythermic method in the temperature range from -11.2 to 61°C. A polythermal solubility diagram of the system was constructed and the crystallization sites of ice, urea, monoethanolammonium oxalate, and the new phase ureamonoethanolammonium oxalate were determined.During the addition of monoethanolammonium oxalate to urea solutions of different concentrations, changes in rheological properties (pH, density, refractive index, viscosity) were recorded, and the results were found to be consistent with the polythermal solubility diagram. A new phase formed during the study of the CO(NH2)2 - HOOC-COOH · NH2C2H4OH - H2O system, ureamonoethanolammonium oxalate, was isolated and analyzed by confirmed using appropriate analytical methods (IR, Thermal, X-ray phase).
{"title":"STUDY OF SOLUBILITY OF CO(NH2)2 - HOOC - COOH · NH2C2H4OH - H2O SYSTEM","authors":"Bakhtiyor Akhmedov, Zhamshid Shukhurov, Ilkhom Abdurakhmanov, Rizamat Begmatov","doi":"10.59957/jctm.v59.i3.2024.3","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.3","url":null,"abstract":"In this work, the interaction of components in the CO(NH2)2 - HOOC - COOH ·NH2C2H4OH - H2O system was studied by visual polythermic method in the temperature range from -11.2 to 61°C. A polythermal solubility diagram of the system was constructed and the crystallization sites of ice, urea, monoethanolammonium oxalate, and the new phase ureamonoethanolammonium oxalate were determined.During the addition of monoethanolammonium oxalate to urea solutions of different concentrations, changes in rheological properties (pH, density, refractive index, viscosity) were recorded, and the results were found to be consistent with the polythermal solubility diagram. A new phase formed during the study of the CO(NH2)2 - HOOC-COOH · NH2C2H4OH - H2O system, ureamonoethanolammonium oxalate, was isolated and analyzed by confirmed using appropriate analytical methods (IR, Thermal, X-ray phase).","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"115 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141002748","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}
Pub Date : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.27
Volodymyr Tsyganov, Sergey Sheyko, Oleksii Hrechanyi, T. Vasilchenko, Elena Kulabneva, A. Hrechana
Considered patterns of formation of the nanostructural state of the surface layer of machine parts during friction under conditions of complex dynamic loading. The results of the complex assessment of the state of the surface layer of samples after friction continuous indentation and scanning methods indenter, an analysis of changes in the work function of the electron from the surface of the samples. Shown that during the friction of steel surfaces, an increase in transverse slippage contributes to the formation of a more uniform surface layer. This decreases its strength, wear resistance, and a more uniform surface microgeometry. This is accompanied by a decrease in the magnitude and spread of the electron work function over the surface. The relationship between the nanostructural state of a polished surface and roughness and reflectivity is presented.
{"title":"FEATURES OF THE FORMATION OF THE NANOSTRUCTURAL STATE OF THE SURFACE LAYER OF STEEL PARTS DURING PROCESSING AND OPERATION","authors":"Volodymyr Tsyganov, Sergey Sheyko, Oleksii Hrechanyi, T. Vasilchenko, Elena Kulabneva, A. Hrechana","doi":"10.59957/jctm.v59.i3.2024.27","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.27","url":null,"abstract":"Considered patterns of formation of the nanostructural state of the surface layer of machine parts during friction under conditions of complex dynamic loading. The results of the complex assessment of the state of the surface layer of samples after friction continuous indentation and scanning methods indenter, an analysis of changes in the work function of the electron from the surface of the samples. Shown that during the friction of steel surfaces, an increase in transverse slippage contributes to the formation of a more uniform surface layer. This decreases its strength, wear resistance, and a more uniform surface microgeometry. This is accompanied by a decrease in the magnitude and spread of the electron work function over the surface. The relationship between the nanostructural state of a polished surface and roughness and reflectivity is presented.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"8 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141004674","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}
Pub Date : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.18
Vladimir Merkulov, Gulnara Ulyeva, Gulzhainat Akhmetova, Andrey Volokitin
Copolymers were obtained in this work and the methodology for their synthesis was worked out. Various fillers were selected for the polymer coating. Resulting copolymers have good adhesion required for composite protective coatings. An experiment was conducted to determine the corrosion resistance of metals coated with copolymers when exposed to aggressive environments, as well as to determine the hardness and thickness of the polymer coatings obtained. It was found that the polymer coating filled with bronze powder, despite the small thickness of 43.4 μm, hasthe best adhesion and corrosion properties, as well as having the highest hardness values of 80.5 HB. Such physical and mechanical properties of polymer coatings allow them to be used as protective coatings for metal products working under the influence of aggressive media.
{"title":"SYNTHESIS OF COPOLYMERS FOR PROTECTIVE COATINGS","authors":"Vladimir Merkulov, Gulnara Ulyeva, Gulzhainat Akhmetova, Andrey Volokitin","doi":"10.59957/jctm.v59.i3.2024.18","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.18","url":null,"abstract":"Copolymers were obtained in this work and the methodology for their synthesis was worked out. Various fillers were selected for the polymer coating. Resulting copolymers have good adhesion required for composite protective coatings. An experiment was conducted to determine the corrosion resistance of metals coated with copolymers when exposed to aggressive environments, as well as to determine the hardness and thickness of the polymer coatings obtained. It was found that the polymer coating filled with bronze powder, despite the small thickness of 43.4 μm, hasthe best adhesion and corrosion properties, as well as having the highest hardness values of 80.5 HB. Such physical and mechanical properties of polymer coatings allow them to be used as protective coatings for metal products working under the influence of aggressive media.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"156 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141001755","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}
Pub Date : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.22
Ahmed Asif Razin, Dewan Sal-Sabil Ahammed, A. Khan, Mohammad Salim Kaiser
Influence of different levels of silicon under a variety of thermal treatment is investigated on the thermophysical behaviour of Al-Si-Cu-Mg automotive alloys. Conventional cast alloys are subjected to T6 heat treatment for age hardening. Hardness values, thermal conductivity along with microstructural observation under different heat-treated conditions are well thought-out to comprehend the ageing performance and the precipitation behaviour of the alloys. From these investigational results it is indicated that two successive hardening peaks take place in the agedalloys. Ageing sequence consists of different phases like a supersaturated solid solution, GP zones, intermediate βʹʹ, intermetallic βʹ, equilibrium β and the Q phase but GP zones and the metastable phases are most likely responsible for these ageing peaks. Thermal conductivity decreases for these precipitates formation during ageing and increases for relieving the internal stress, dissolution of metastable phase and coarsening the precipitation of the alloys. Addingup of Si to the alloy showed earlier ageing peaks with higher intensities intended for its increasing properties of heterogeneous nucleation and diffusion kinetics. After ageing around at 200°C for four hours the alloys offer the height hardness. Microstructural study reveals that eutectic silicon makes the grain boundary coarsen and beyond the eutectic composition the star-shaped blocky primary Si is formed. Subsequent to ageing at 350oC for one hour the alloys reach completely recrystallized state.
{"title":"THERMOPHYSICAL PROPERTIES OF HYPOEUTECTIC, EUTECTIC AND HYPEREUTECTIC Al-Si AUTOMOTIVE ALLOYS UNDER AGEING TREATMENT","authors":"Ahmed Asif Razin, Dewan Sal-Sabil Ahammed, A. Khan, Mohammad Salim Kaiser","doi":"10.59957/jctm.v59.i3.2024.22","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.22","url":null,"abstract":"Influence of different levels of silicon under a variety of thermal treatment is investigated on the thermophysical behaviour of Al-Si-Cu-Mg automotive alloys. Conventional cast alloys are subjected to T6 heat treatment for age hardening. Hardness values, thermal conductivity along with microstructural observation under different heat-treated conditions are well thought-out to comprehend the ageing performance and the precipitation behaviour of the alloys. From these investigational results it is indicated that two successive hardening peaks take place in the agedalloys. Ageing sequence consists of different phases like a supersaturated solid solution, GP zones, intermediate βʹʹ, intermetallic βʹ, equilibrium β and the Q phase but GP zones and the metastable phases are most likely responsible for these ageing peaks. Thermal conductivity decreases for these precipitates formation during ageing and increases for relieving the internal stress, dissolution of metastable phase and coarsening the precipitation of the alloys. Addingup of Si to the alloy showed earlier ageing peaks with higher intensities intended for its increasing properties of heterogeneous nucleation and diffusion kinetics. After ageing around at 200°C for four hours the alloys offer the height hardness. Microstructural study reveals that eutectic silicon makes the grain boundary coarsen and beyond the eutectic composition the star-shaped blocky primary Si is formed. Subsequent to ageing at 350oC for one hour the alloys reach completely recrystallized state.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"70 s288","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141002291","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}
Pub Date : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.29
Atanas V. Atanassov, D. Pilev, F. Tomova
Emotions are one of the main ways of communication between people and of expressing attitudes towards objects, products, services, etc. They are divided to verbal and non-verbal classes. Human speech and intonation belong to the first class, and to the second (non-verbal) facial and body emotions, known as body language. The subject of this report is the development of multimodal deep learning system intended to recognize facial and body emotions and their relationship with the scene (weather) in which they occur. It is based on three deep learning neural networks (DNN) each one for recognition of facial emotion, body emotion and weather. Combining their results, we improve significantly the final facial emotion recognition (FER) results.
{"title":"MULTIMODAL SYSTEM FOR FACIAL EMOTION RECOGNITION BASED ON DEEP LEARNING","authors":"Atanas V. Atanassov, D. Pilev, F. Tomova","doi":"10.59957/jctm.v59.i3.2024.29","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.29","url":null,"abstract":"Emotions are one of the main ways of communication between people and of expressing attitudes towards objects, products, services, etc. They are divided to verbal and non-verbal classes. Human speech and intonation belong to the first class, and to the second (non-verbal) facial and body emotions, known as body language. The subject of this report is the development of multimodal deep learning system intended to recognize facial and body emotions and their relationship with the scene (weather) in which they occur. It is based on three deep learning neural networks (DNN) each one for recognition of facial emotion, body emotion and weather. Combining their results, we improve significantly the final facial emotion recognition (FER) results.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141003995","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}
Pub Date : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.30
Yovko Rakanov
The present study investigates topology for battery charging units (BCU) with simple design and power factor correction. It has a galvanic isolation between the grid and the battery, which is one of the law and standard requirements. The impulse transformer ensures galvanic isolation, which makes the topology suitable for onboard electric vehicles (EV) charging units (OBC). The study also presents a simulation model a simulation model with the help of which a simulation is conducted and a result is obtained.
{"title":"TOPOLOGY OF GALVANIC ISOLATED BATTERY CHARGING UNIT WITH POWER FACTOR CORRECTION","authors":"Yovko Rakanov","doi":"10.59957/jctm.v59.i3.2024.30","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.30","url":null,"abstract":"The present study investigates topology for battery charging units (BCU) with simple design and power factor correction. It has a galvanic isolation between the grid and the battery, which is one of the law and standard requirements. The impulse transformer ensures galvanic isolation, which makes the topology suitable for onboard electric vehicles (EV) charging units (OBC). The study also presents a simulation model a simulation model with the help of which a simulation is conducted and a result is obtained.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"25 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141004939","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}
Pub Date : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.2
Sokaina Hemdan
In this study, the spectrophotometric studies of aqueous ethanol solution of Congo red in various buffers solutions at room temperature 25oC and at different ionic strength of 0.05, 0.1, 0.3, and 0.5 KCl mol L-1 were investigated. The acidity constants of Congo red were estimated by three different methods. The two protonation stages were observed in pH range 2 - 4 and 4 - 6 as result as protonation of amino group and azo groups. The dependence of absorption spectra of Congo red on the ionic strength of solutions which exhibited blue shift with increases ionic strength in addition the shape and intensity were varied. Therefore, the acid-base equilibria shifted toward the higher pHs with the rise in ionic strength. Also, the acidity constants were affected by the ionic strength which the acidity constants decrease with increasing ionic strength of solution because the electrostatic interaction force increased.
{"title":"THE DEPENDENCE OF ACID-BASE EQUILBRIA AND ACIDITY CONSTANTS OF CONGO RED IN BUFFER SOLUTIONS ON THE IONIC STRENGTH","authors":"Sokaina Hemdan","doi":"10.59957/jctm.v59.i3.2024.2","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.2","url":null,"abstract":"In this study, the spectrophotometric studies of aqueous ethanol solution of Congo red in various buffers solutions at room temperature 25oC and at different ionic strength of 0.05, 0.1, 0.3, and 0.5 KCl mol L-1 were investigated. The acidity constants of Congo red were estimated by three different methods. The two protonation stages were observed in pH range 2 - 4 and 4 - 6 as result as protonation of amino group and azo groups. The dependence of absorption spectra of Congo red on the ionic strength of solutions which exhibited blue shift with increases ionic strength in addition the shape and intensity were varied. Therefore, the acid-base equilibria shifted toward the higher pHs with the rise in ionic strength. Also, the acidity constants were affected by the ionic strength which the acidity constants decrease with increasing ionic strength of solution because the electrostatic interaction force increased.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"4 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141004547","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}
Pub Date : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.9
N. Kaneva, A. Bojinova, R. Mladenova, Hristo Kolev, Bozhidar Stefanov
In the study, the photocatalytic activity of TiO2 films that are created by dip-coating from a sol that contained titanium (IV) isopropoxide, monoethanolamine, and 2-methoxyethanol is demonstrated. Through photo-fixation of Ag (I) ions with varied concentration (10-2 - 10-4 M) in the water phase under UV illumination, the films are subsequently surface-modified with Ag co-catalyst layers. Scanning Electron Microscopy (SEM), X-Ray Photoelectron Spectroscopy (XPS), Ultraviolet-Visible (UV) Spectroscopy, and Electron Paramagnetic Resonance (EPR) techniques are used to physically characterize the samples. Results reveal that the modification of the co-catalyst had no impact on the thickness and porosity of the films. In addition, the study show that the modified TiO2 films had increased photocatalytic activity. All the characterization methods used have shown the formationof surface - bound Ag (I) species and metallic silver nanoclusters. By measuring the Methylene Blue (MB) dye degradation under UV light illumination, as - prepared and Ag -modified TiO2 films are evaluated for their photocatalytic activity, and the impact of the silver precursor concentration during photo-fixation is investigated.The highest catalytic activity is seen for films that have been modified at a concentration of Ag (I) of 10-2 M. Ordered from highest to lowest, the MB photodegradation rate constants are TiO2 < TiO2 /Ag, 10-4 < TiO2 /Ag, 10-3 < TiO2 / Ag, 10-2.
该研究证明了从含有异丙醇钛 (IV)、单乙醇胺和 2-甲氧基乙醇的溶液中通过浸涂产生的二氧化钛薄膜的光催化活性。在紫外线照射下，水相中不同浓度（10-2 - 10-4 M）的 Ag (I) 离子经过光固化，随后薄膜表面被Ag 助催化剂层修饰。扫描电子显微镜 (SEM)、X 射线光电子能谱 (XPS)、紫外-可见 (UV) 光谱和电子顺磁共振 (EPR) 技术用于表征样品的物理特性。结果表明，共催化剂的改性对薄膜的厚度和孔隙率没有影响。此外，研究还表明，改性后的二氧化钛薄膜具有更高的光催化活性。使用的所有表征方法都显示了表面结合的 Ag (I) 物种和金属银纳米团簇的形成。通过测量紫外线照射下亚甲蓝（MB）染料的降解情况，评估了制备的和银修饰的二氧化钛薄膜的光催化活性，并研究了光固化过程中银前驱体浓度的影响。催化活性最高的是 Ag (I) 浓度为 10-2 M 的改性薄膜。MB 光降解速率常数从高到低依次为 TiO2 < TiO2 /Ag, 10-4 < TiO2 /Ag, 10-3 < TiO2 /Ag, 10-2。
{"title":"SYNTHESIS OF Ag-MODIFIED TiO2 SOL-GEL FILMS AND ITS APPLICATION AS PHOTOCATALYSTS FOR METHYLENE BLUE DEGRADATION","authors":"N. Kaneva, A. Bojinova, R. Mladenova, Hristo Kolev, Bozhidar Stefanov","doi":"10.59957/jctm.v59.i3.2024.9","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.9","url":null,"abstract":"In the study, the photocatalytic activity of TiO2 films that are created by dip-coating from a sol that contained titanium (IV) isopropoxide, monoethanolamine, and 2-methoxyethanol is demonstrated. Through photo-fixation of Ag (I) ions with varied concentration (10-2 - 10-4 M) in the water phase under UV illumination, the films are subsequently surface-modified with Ag co-catalyst layers. Scanning Electron Microscopy (SEM), X-Ray Photoelectron Spectroscopy (XPS), Ultraviolet-Visible (UV) Spectroscopy, and Electron Paramagnetic Resonance (EPR) techniques are used to physically characterize the samples. Results reveal that the modification of the co-catalyst had no impact on the thickness and porosity of the films. In addition, the study show that the modified TiO2 films had increased photocatalytic activity. All the characterization methods used have shown the formationof surface - bound Ag (I) species and metallic silver nanoclusters. By measuring the Methylene Blue (MB) dye degradation under UV light illumination, as - prepared and Ag -modified TiO2 films are evaluated for their photocatalytic activity, and the impact of the silver precursor concentration during photo-fixation is investigated.The highest catalytic activity is seen for films that have been modified at a concentration of Ag (I) of 10-2 M. Ordered from highest to lowest, the MB photodegradation rate constants are TiO2 < TiO2 /Ag, 10-4 < TiO2 /Ag, 10-3 < TiO2 / Ag, 10-2.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"26 41","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141005631","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}
Pub Date : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.14
Gulzhainat Akhmetova, Gulnara Ulyeva, K. Tuyskhan, Irina Volokitina
The article presents some existing methods of producing silicon carbide, forms and types of silicon carbide, various compositions and formulations, production technology. The authors proposed a new method of processing silicon production waste - microsilica by spark plasma sintering with a carbon-containing reducing agent (soot) which produces a silicon carbide compound. Studies have shown that sintered silicon carbide has improved strength properties. Thus, the possibility of application of production wastes to create new composite materials characterized by a certain complex of properties is confirmed.
{"title":"APPLICATION OF SPARK PLASMA SINTERING AS A METHOD FOR PRODUCING NEW CERAMIC MATERIALS FROM SILICON PRODUCTION WASTE","authors":"Gulzhainat Akhmetova, Gulnara Ulyeva, K. Tuyskhan, Irina Volokitina","doi":"10.59957/jctm.v59.i3.2024.14","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.14","url":null,"abstract":"The article presents some existing methods of producing silicon carbide, forms and types of silicon carbide, various compositions and formulations, production technology. The authors proposed a new method of processing silicon production waste - microsilica by spark plasma sintering with a carbon-containing reducing agent (soot) which produces a silicon carbide compound. Studies have shown that sintered silicon carbide has improved strength properties. Thus, the possibility of application of production wastes to create new composite materials characterized by a certain complex of properties is confirmed.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"6 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141004494","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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