Pub Date : 2020-09-01DOI: 10.2298/hemind200615022j
A. Jelić, M. Sekulić, M. Stamenović, Vukašin Ugrinović, S. Putic
The paper presents static and dynamic tests of carbon/epoxy composite materials with fiber orientation at 0?/90? and ?45?. The main tensile properties were determined as a basis for subsequent dynamic tests, in which permanent dynamic strength, crack growth, and crack growth rate in the material due to the action of fatigue load were assessed. Comparisons were made regarding the structure of the tested specimens. Samples were obtained from prepregs with a specific density of 1600 kg/m3. The tests were performed at room temperature. Scanning electron microscopy (SEM) was used to analyze the damage in the material during these tests, the mechanisms of their further damage progression and, the impact on the growth and growth rate of the initial crack in the material. The analysis of numerical results and micromechanical analysis confirmed the dominant role of the reinforcing structural element in the material in all performed tests. The obtained results are of great importance in the application of composite materials of such structures under different operating conditions and load regimes.
{"title":"Micromechanical analysis of fatigue and crack growth in carbon-fiber epoxy composites based on mechanical testing","authors":"A. Jelić, M. Sekulić, M. Stamenović, Vukašin Ugrinović, S. Putic","doi":"10.2298/hemind200615022j","DOIUrl":"https://doi.org/10.2298/hemind200615022j","url":null,"abstract":"The paper presents static and dynamic tests of carbon/epoxy composite materials with fiber orientation at 0?/90? and ?45?. The main tensile properties were determined as a basis for subsequent dynamic tests, in which permanent dynamic strength, crack growth, and crack growth rate in the material due to the action of fatigue load were assessed. Comparisons were made regarding the structure of the tested specimens. Samples were obtained from prepregs with a specific density of 1600 kg/m3. The tests were performed at room temperature. Scanning electron microscopy (SEM) was used to analyze the damage in the material during these tests, the mechanisms of their further damage progression and, the impact on the growth and growth rate of the initial crack in the material. The analysis of numerical results and micromechanical analysis confirmed the dominant role of the reinforcing structural element in the material in all performed tests. The obtained results are of great importance in the application of composite materials of such structures under different operating conditions and load regimes.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"16 6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85471890","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 : 2020-09-01DOI: 10.2298/hemind200424020t
N. Toro, K. Pérez, M. Saldaña, E. Salinas-Rodríguez, Pía C. Hernández
Currently, there is a large amount of mineral resources not being exploited in large copper minings, a clear example are black copper minerals. These resources are generally not incorpo-rated into the extraction circuits or are not treated, either in stocks, leach pads, or debris. These exotic minerals have considerable amounts of Cu and Mn, which are commercially very attractive. They are refractory to conventional leaching processes, therefore, the use of reducing agents is necessary for treatment of these minerals in order to dissolve the present MnO2, which in turn allows Cu extraction. In this research, iron scrap Fe0 was used as a reducing agent for the dissolution of Mn from a black copper mineral in an acidic medium and compared to previous studies of the use of Fe2+ under the same conditions. In addition, the effects of a pretreatment process (agglomeration and curing) by adding NaCl are investigated in order to favor the reduction of MnO2. Finally, it was discovered that there is a higher kinetics of dissolution of Mn when working with Fe0 in short periods of time, although similar extraction efficiencies are obtained after prolonged times. The pretreatment process by adding NaCl resulted in increased Mn extraction in short periods of time (30 min). At applying high concentrations of the reducing agent, the effect of particle size on the dissolution rate of MnO2 was shown to be insignificant.
{"title":"Treatment of black copper with the use of iron scrap - part I","authors":"N. Toro, K. Pérez, M. Saldaña, E. Salinas-Rodríguez, Pía C. Hernández","doi":"10.2298/hemind200424020t","DOIUrl":"https://doi.org/10.2298/hemind200424020t","url":null,"abstract":"Currently, there is a large amount of mineral resources not being exploited in large copper minings, a clear example are black copper minerals. These resources are generally not incorpo-rated into the extraction circuits or are not treated, either in stocks, leach pads, or debris. These exotic minerals have considerable amounts of Cu and Mn, which are commercially very attractive. They are refractory to conventional leaching processes, therefore, the use of reducing agents is necessary for treatment of these minerals in order to dissolve the present MnO2, which in turn allows Cu extraction. In this research, iron scrap Fe0 was used as a reducing agent for the dissolution of Mn from a black copper mineral in an acidic medium and compared to previous studies of the use of Fe2+ under the same conditions. In addition, the effects of a pretreatment process (agglomeration and curing) by adding NaCl are investigated in order to favor the reduction of MnO2. Finally, it was discovered that there is a higher kinetics of dissolution of Mn when working with Fe0 in short periods of time, although similar extraction efficiencies are obtained after prolonged times. The pretreatment process by adding NaCl resulted in increased Mn extraction in short periods of time (30 min). At applying high concentrations of the reducing agent, the effect of particle size on the dissolution rate of MnO2 was shown to be insignificant.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"81 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77133732","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}
{"title":"Fighting fake science: The key role of scientists","authors":"B. Obradovic, Ana Barcus","doi":"10.2298/hemind20082924o","DOIUrl":"https://doi.org/10.2298/hemind20082924o","url":null,"abstract":"<jats:p>nema</jats:p>","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81385231","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 : 2020-09-01DOI: 10.2298/hemind200413021d
V. Djurić, V. Mitić, N. Deletic, M. Ilic, B. Ćirković, V. Stankov-Jovanović
Biperiden, an antiparkinsonian anticholinergic drug, has been found to inhibit enzymatic hydrolysis of butyrylthiocholine iodide, which is catalyzed by serum cholinesterase. By measuring the difference in the basic and inhibitory hydrolysis reaction rates, in the presence of biperiden as an inhibitor, it is possible to develop a kinetic method for its determination. Both systems, enzyme-substrate-chromogen and enzyme-substrate-chromogen-inhibitor, were characterized by biochemical parameters (KM = 0.326 ? 0.330 mmol dm-3; Vmax = 40 - - 99 ?mol dm-3 min-1), while inhibition was defined as non-competitive with the constant of inhibition Ki = 6.142 ?mol dm-3. The reaction conditions have been optimized followed by determination of the calibration curve, the corresponding equation and the limits of detection and quantification yielding 3.84 and 12.80 nmol dm-3, respectively. Using the calibration chart, it is possible to determine biperiden in different samples in the concentration range of 0.035?35.940 ?mol dm-3. Influence of a number of substances, found in the sample, on the reaction rate was also examined. The optimized method was applied for determination of biperiden in pharmaceutical preparations. Accuracy of the method was tested using the standard addition method. The proposed method has good sensitivity, selectivity, it is simple and fast, and above all easily accessible, and thus applicable in biochemical and pharmaceutical laboratories.
{"title":"A novel kinetic cholinesterase-inhibition based method for quantification of biperiden in pharmaceutical preparations","authors":"V. Djurić, V. Mitić, N. Deletic, M. Ilic, B. Ćirković, V. Stankov-Jovanović","doi":"10.2298/hemind200413021d","DOIUrl":"https://doi.org/10.2298/hemind200413021d","url":null,"abstract":"Biperiden, an antiparkinsonian anticholinergic drug, has been found to inhibit enzymatic hydrolysis of butyrylthiocholine iodide, which is catalyzed by serum cholinesterase. By measuring the difference in the basic and inhibitory hydrolysis reaction rates, in the presence of biperiden as an inhibitor, it is possible to develop a kinetic method for its determination. Both systems, enzyme-substrate-chromogen and enzyme-substrate-chromogen-inhibitor, were characterized by biochemical parameters (KM = 0.326 ? 0.330 mmol dm-3; Vmax = 40 - - 99 ?mol dm-3 min-1), while inhibition was defined as non-competitive with the constant of inhibition Ki = 6.142 ?mol dm-3. The reaction conditions have been optimized followed by determination of the calibration curve, the corresponding equation and the limits of detection and quantification yielding 3.84 and 12.80 nmol dm-3, respectively. Using the calibration chart, it is possible to determine biperiden in different samples in the concentration range of 0.035?35.940 ?mol dm-3. Influence of a number of substances, found in the sample, on the reaction rate was also examined. The optimized method was applied for determination of biperiden in pharmaceutical preparations. Accuracy of the method was tested using the standard addition method. The proposed method has good sensitivity, selectivity, it is simple and fast, and above all easily accessible, and thus applicable in biochemical and pharmaceutical laboratories.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91351969","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 : 2020-07-27DOI: 10.2298/hemind200421019s
M. Šimic, A. Alil, Sanja Martinović, M. Vlahović, A. Savić, T. Volkov-Husović
High-temperature materials are used in a wide range of industries and applications such as gas turbine engines for aircrafts, power and nuclear power plants, different types of furnaces, including blast furnaces, some fuel cells, industrial gas turbines, different types of reactors, engines, electronic and lighting devices, and many others. Demands for high-temperature materials are becoming more and more challenging every year. To perform efficiently, effectively and at the same time to be economically viable, the materials used at high temperatures must have certain characteristics that are particularly expected for applying under such extreme conditions, for example, the strength and thermal resistance. In the present review, some important requirements that should be satisfied by high temperature materials will be discussed. Furthermore, the focus is put on refractory concretes, ceramics, intermetallic alloys, and composites as four different categories of these materials, which are also considered in respect to possibilities to overcome some of the current challenges.
{"title":"High temperature materials: properties, demands and applications","authors":"M. Šimic, A. Alil, Sanja Martinović, M. Vlahović, A. Savić, T. Volkov-Husović","doi":"10.2298/hemind200421019s","DOIUrl":"https://doi.org/10.2298/hemind200421019s","url":null,"abstract":"High-temperature materials are used in a wide range of industries and applications such as gas turbine engines for aircrafts, power and nuclear power plants, different types of furnaces, including blast furnaces, some fuel cells, industrial gas turbines, different types of reactors, engines, electronic and lighting devices, and many others. Demands for high-temperature materials are becoming more and more challenging every year. To perform efficiently, effectively and at the same time to be economically viable, the materials used at high temperatures must have certain characteristics that are particularly expected for applying under such extreme conditions, for example, the strength and thermal resistance. In the present review, some important requirements that should be satisfied by high temperature materials will be discussed. Furthermore, the focus is put on refractory concretes, ceramics, intermetallic alloys, and composites as four different categories of these materials, which are also considered in respect to possibilities to overcome some of the current challenges.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76981582","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 : 2020-07-01DOI: 10.2298/hemind191216014d
Damir Barbir, Pero Dabic
For the preparation of modern cement and concrete, supplementary cementitious materials (SCM) have become essential ingredients. The technical, economic and environmental advantages of using SCM have become unquestionable. The main technical reasons for their use are the improvement of the workability of fresh concrete and durability of hardened concrete. Actually, SCM affect almost all concrete properties, while environmental and economic reasons may be more significant than technical reasons. These ingredients can reduce the amount of Portland cement used in cement composites, resulting in economic and environmental benefits. In addition, many of the SCM are industrial by-products, which can otherwise be considered as waste. This paper presents a literature review of the present knowledge on the impact of natural zeolite, waste construction brick and waste container glass on physical, chemical and mechanical properties of Portland cement as the most commonly used cement in the world.
{"title":"Implementation of natural and artificial materials in Portland cement","authors":"Damir Barbir, Pero Dabic","doi":"10.2298/hemind191216014d","DOIUrl":"https://doi.org/10.2298/hemind191216014d","url":null,"abstract":"For the preparation of modern cement and concrete, supplementary cementitious materials (SCM) have become essential ingredients. The technical, economic and environmental advantages of using SCM have become unquestionable. The main technical reasons for their use are the improvement of the workability of fresh concrete and durability of hardened concrete. Actually, SCM affect almost all concrete properties, while environmental and economic reasons may be more significant than technical reasons. These ingredients can reduce the amount of Portland cement used in cement composites, resulting in economic and environmental benefits. In addition, many of the SCM are industrial by-products, which can otherwise be considered as waste. This paper presents a literature review of the present knowledge on the impact of natural zeolite, waste construction brick and waste container glass on physical, chemical and mechanical properties of Portland cement as the most commonly used cement in the world.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78812008","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 : 2020-07-01DOI: 10.2298/hemind200320016b
M. Bebic, M. Banjanac, M. Ćorović, D. Milivojevič, B. Simovic, Z. A. Vukoicic, D. Mitrović, I. D. Bezbradica
In this study, immobilization of laccase from Trametes versicolor on eight Lifetech? supports, with different characteristics (pore size, length of the spacer arm and functional groups), was studied and optimized for intended use in bioremediation for decolorization of industrial wastewaters. Out of six tested amino-functionalized supports, the most promising carrier was proved to be porous Lifetech? ECR8309F with primary amino groups and a C2 spacer arm. Onto this support, laccase is attached by forming electrostatic interactions so that the most active preparation has shown the activity of 66876 U/g support. On the other hand, during immobilization of laccase on epoxy-functionalized Lifetech? ECR8285F, via hydrophobic interactions and covalent bonding confirmed by a desorption assay, immobilization yield of 60 % and the activity of 118929 U/g were accomplished. Furthermore, immobilized enzyme on this support showed high capacity for decolorization of dyes (Lanaset? Violet B, Lanaset? Blue 2R, bromothymol blue and bromocresol green), by combination of both adsorption and enzyme degradation. Decolorization was in the range of 88 to 96 % after 4 h, with more than 80 % achieved after only 45 min. Also, this preparation demonstrated high operational stability during seven consecutive reuses in all examined dye reaction systems.
{"title":"Immobilization of laccase from Trametes versicolor on Lifetechtm supports for applications in degradation of industrial dyes","authors":"M. Bebic, M. Banjanac, M. Ćorović, D. Milivojevič, B. Simovic, Z. A. Vukoicic, D. Mitrović, I. D. Bezbradica","doi":"10.2298/hemind200320016b","DOIUrl":"https://doi.org/10.2298/hemind200320016b","url":null,"abstract":"In this study, immobilization of laccase from Trametes versicolor on eight Lifetech? supports, with different characteristics (pore size, length of the spacer arm and functional groups), was studied and optimized for intended use in bioremediation for decolorization of industrial wastewaters. Out of six tested amino-functionalized supports, the most promising carrier was proved to be porous Lifetech? ECR8309F with primary amino groups and a C2 spacer arm. Onto this support, laccase is attached by forming electrostatic interactions so that the most active preparation has shown the activity of 66876 U/g support. On the other hand, during immobilization of laccase on epoxy-functionalized Lifetech? ECR8285F, via hydrophobic interactions and covalent bonding confirmed by a desorption assay, immobilization yield of 60 % and the activity of 118929 U/g were accomplished. Furthermore, immobilized enzyme on this support showed high capacity for decolorization of dyes (Lanaset? Violet B, Lanaset? Blue 2R, bromothymol blue and bromocresol green), by combination of both adsorption and enzyme degradation. Decolorization was in the range of 88 to 96 % after 4 h, with more than 80 % achieved after only 45 min. Also, this preparation demonstrated high operational stability during seven consecutive reuses in all examined dye reaction systems.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"188 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86729233","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 : 2020-07-01DOI: 10.2298/hemind200329015s
Jasmina Stojkovska, Jovana Zvicer, M. Milivojevic, Isidora P Petrović, M. Stevanović, B. Obradovic
Development of drugs is a complex, time- and cost-consuming process due to the lack of standardized and reliable characterization techniques and models. Traditionally, drug screening is based on in vitro analysis using two-dimensional (2D) cell cultures followed by in vivo animal testing. Unfortunately, application of the obtained results to humans in about 90 % of cases fails. Therefore, it is important to develop and improve cell-based systems that can mimic the in vivo-like conditions to provide more reliable results. In this paper, we present development and validation of a novel, user-friendly perfusion bioreactor system for single use aimed for cancer research, drug screening, anti-cancer drug response studies, biomaterial characterization, and tissue engineering. Simple design of the perfusion bioreactor provides direct medium flow at physiological velocities (100?250 ?m s-1) through samples of different sizes and shapes. Biocompatibility of the bioreactor was confirmed in short term cultivation studies of cervical carcinoma SiHa cells immobilized in alginate microfibers under continuous medium flow. The results have shown preserved cell viability indicating that the perfusion bioreactor in conjunction with alginate hydrogels as cell carriers could be potentially used as a tool for controlled anti-cancer drug screening in a 3D environment.
由于缺乏标准化和可靠的表征技术和模型，药物的开发是一个复杂、耗时和成本高的过程。传统上，药物筛选是基于使用二维(2D)细胞培养的体外分析，然后进行体内动物试验。不幸的是，在大约90%的情况下，将获得的结果应用于人类失败。因此，重要的是开发和改进基于细胞的系统，可以模拟体内样条件，以提供更可靠的结果。在本文中，我们介绍了一种新型的、用户友好的灌注生物反应器系统的开发和验证，该系统用于癌症研究、药物筛选、抗癌药物反应研究、生物材料表征和组织工程。灌注生物反应器设计简单，可提供生理速度(100?250 μ m s-1)，通过不同尺寸和形状的样品。在连续培养基流动条件下，对海藻酸盐微纤维固定的宫颈癌SiHa细胞进行了短期培养研究，证实了该生物反应器的生物相容性。结果显示保存的细胞活力表明，与海藻酸盐水凝胶作为细胞载体的灌注生物反应器可以潜在地用作在3D环境中进行可控抗癌药物筛选的工具。
{"title":"Validation of a novel perfusion bioreactor system in cancer research","authors":"Jasmina Stojkovska, Jovana Zvicer, M. Milivojevic, Isidora P Petrović, M. Stevanović, B. Obradovic","doi":"10.2298/hemind200329015s","DOIUrl":"https://doi.org/10.2298/hemind200329015s","url":null,"abstract":"Development of drugs is a complex, time- and cost-consuming process due to the lack of standardized and reliable characterization techniques and models. Traditionally, drug screening is based on in vitro analysis using two-dimensional (2D) cell cultures followed by in vivo animal testing. Unfortunately, application of the obtained results to humans in about 90 % of cases fails. Therefore, it is important to develop and improve cell-based systems that can mimic the in vivo-like conditions to provide more reliable results. In this paper, we present development and validation of a novel, user-friendly perfusion bioreactor system for single use aimed for cancer research, drug screening, anti-cancer drug response studies, biomaterial characterization, and tissue engineering. Simple design of the perfusion bioreactor provides direct medium flow at physiological velocities (100?250 ?m s-1) through samples of different sizes and shapes. Biocompatibility of the bioreactor was confirmed in short term cultivation studies of cervical carcinoma SiHa cells immobilized in alginate microfibers under continuous medium flow. The results have shown preserved cell viability indicating that the perfusion bioreactor in conjunction with alginate hydrogels as cell carriers could be potentially used as a tool for controlled anti-cancer drug screening in a 3D environment.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89333858","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 : 2020-05-01DOI: 10.2298/hemind191011011m
Darko Manjenčić, J. Seitsonen, T. Radusin, N. Vukić, J. Budinski-Simendic, J. Cakić, I. Ristić
In this study, the influence of nanosilicon(IV)-oxide (with hydrophobic and hydrophilic functionalized surfaces) on the properties of siloxane elastomers was studied. The elastomers were prepared from vinyl and hydrogen oligosiloxanes, while the nanocomposites were obtained by addition of nanofillers at different concentrations (1, 5, 10 and 20 wt%). The chemical structure of the obtained materials was analyzed by Fourier transform infrared spectroscopy. Transmission electron microscopy confirmed good dispersion of the hydrophobic filler within the polymer matrix, while the hydrophilic filler formed a net on the siloxane sample. Type of the filler modification did not affect hardness of the siloxane hybrid materials, while the samples with the highest content of hydrophobic nanosilica have shown the highest value of tensile strength. Influence of the nanosilica type on thermal degradation of elastomeric materials was investigated by using thermogravimetric analysis, while the influence of the fillers on the phase transition temperature was analyzed by differential scanning calorimetry. Lower compatibility of the hydrophobic matrix and hydrophilic filler caused a decrease in the crystalline melting temperature with the lowest value determined for the sample with the highest filler loading. Increase in the nanofiller content resulted in the improved thermal stability of the obtained hybrid materials.
{"title":"Influence of nanofillers on the properties of siloxane elastomers","authors":"Darko Manjenčić, J. Seitsonen, T. Radusin, N. Vukić, J. Budinski-Simendic, J. Cakić, I. Ristić","doi":"10.2298/hemind191011011m","DOIUrl":"https://doi.org/10.2298/hemind191011011m","url":null,"abstract":"In this study, the influence of nanosilicon(IV)-oxide (with hydrophobic and hydrophilic functionalized surfaces) on the properties of siloxane elastomers was studied. The elastomers were prepared from vinyl and hydrogen oligosiloxanes, while the nanocomposites were obtained by addition of nanofillers at different concentrations (1, 5, 10 and 20 wt%). The chemical structure of the obtained materials was analyzed by Fourier transform infrared spectroscopy. Transmission electron microscopy confirmed good dispersion of the hydrophobic filler within the polymer matrix, while the hydrophilic filler formed a net on the siloxane sample. Type of the filler modification did not affect hardness of the siloxane hybrid materials, while the samples with the highest content of hydrophobic nanosilica have shown the highest value of tensile strength. Influence of the nanosilica type on thermal degradation of elastomeric materials was investigated by using thermogravimetric analysis, while the influence of the fillers on the phase transition temperature was analyzed by differential scanning calorimetry. Lower compatibility of the hydrophobic matrix and hydrophilic filler caused a decrease in the crystalline melting temperature with the lowest value determined for the sample with the highest filler loading. Increase in the nanofiller content resulted in the improved thermal stability of the obtained hybrid materials.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"6 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72578783","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 : 2020-05-01DOI: 10.2298/hemind200427013z
E. Živković
nema
{"title":"The role of science in modern society","authors":"E. Živković","doi":"10.2298/hemind200427013z","DOIUrl":"https://doi.org/10.2298/hemind200427013z","url":null,"abstract":"<jats:p>nema</jats:p>","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75316026","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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