45 results on '"Nedeljković, Dragutin"'
Search Results
2. On the evaluation of mono-nanofluids’ density using a radial basis function neural network optimized by evolutionary algorithms
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Deymi, Omid, Rezaei, Farzaneh, Atashrouz, Saeid, Nedeljkovic, Dragutin, Mohaddespour, Ahmad, and Hemmati-Sarapardeh, Abdolhossein
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- 2024
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3. Carbon capture technologies: A review on technology readiness level
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Hekmatmehr, Hesamedin, Esmaeili, Ali, Pourmahdi, Maryam, Atashrouz, Saeid, Abedi, Ali, Ali Abuswer, Meftah, Nedeljkovic, Dragutin, Latifi, Mohammad, Farag, Sherif, and Mohaddespour, Ahmad
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- 2024
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4. Polymeric Composite Dense Membranes Applied for the Flue Gas Treatment
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Nedeljkovic, Dragutin, Alam, Shafiq, editor, Guillen, Donna Post, editor, Tesfaye, Fiseha, editor, Zhang, Lei, editor, Hockaday, Susanna A.C., editor, Neelameggham, Neale R., editor, Peng, Hong, editor, Haque, Nawshad, editor, and Liu, Yan, editor
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- 2023
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5. Effect of Moisture and High Temperature to Separation Properties of Mixed Matrix Membranes
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Nedeljkovic, Dragutin, Lazou, Adamantia, editor, Daehn, Katrin, editor, Fleuriault, Camille, editor, Gökelma, Mertol, editor, Olivetti, Elsa, editor, and Meskers, Christina, editor
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- 2022
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6. Data-driven modeling of H2 solubility in hydrocarbons using white-box approaches
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Hadavimoghaddam, Fahimeh, Mohammadi, Mohammad-Reza, Atashrouz, Saeid, Nedeljkovic, Dragutin, Hemmati-Sarapardeh, Abdolhossein, and Mohaddespour, Ahmad
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- 2022
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7. Homogenization of the Dense Composite Membranes for Carbon Dioxide Separation
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Nedeljkovic, Dragutin, Baba, Alafara Abdullahi, editor, Zhang, Lei, editor, Guillen, Donna P., editor, Neelameggham, Neale R., editor, Peng, Hong, editor, and Zhong, Yulin, editor
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- 2021
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8. Effect of Moisture on the Mechanical Properties of Wood–Plastic Composites Hybridized with Metal Grid Layers
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Perišić, Srdjan, primary, Kalevski, Katarina, additional, Grujić, Aleksandar, additional, Nedeljković, Dragutin, additional, Stajić-Trošić, Jasna, additional, and Radojević, Vesna, additional
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- 2023
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9. Magneto-Mechanical and Thermal Properties of Nd-Fe-B-Epoxy-Bonded Composite Materials
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Grujić, Aleksandar, primary, Nedeljković, Dragutin, additional, Stajić-Trošić, Jasna, additional, Stijepović, Mirko Z., additional, Alnouri, Sabla, additional, and Perišić, Srdjan, additional
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- 2023
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10. Effect of Moisture on the Mechanical Properties of Wood–Plastic Composites Hybridized with Metal Grid Layers
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Perišić, Srđan, Kalevski, Katarina, Grujić, Aleksandar, Nedeljković, Dragutin, Stajić-Trošić, Jasna, Radojević, Vesna, Perišić, Srđan, Kalevski, Katarina, Grujić, Aleksandar, Nedeljković, Dragutin, Stajić-Trošić, Jasna, and Radojević, Vesna
- Abstract
Wood–plastic composites (WPCs) are some of the most common modern composite materials for interior and exterior design that combine natural waste wood properties and the molding possibility of a thermoplastic polymer binder. The addition of reinforcing elements, binding agents, pigments, and coatings, as well as changes to the microstructure and composition, can all affect the quality of WPCs for particular purposes. To improve the properties, hybrid composite panels of WPCs with 30 wt. % and 40 wt. % of wood content and reinforced with one or three metal grid layers were prepared sequentially by extrusion and hot pressure molding. The results show an average 20% higher moisture absorption for composites with higher wood content. A high impact test (HIT) revealed that the absorbed energy of deformation increased with the number of metal grid layers, regardless of the wood content, around two times for all samples before water immersion and around ten times after water absorption. Also, absorbed energy increases with raised wood content, which is most pronounced in three-metal-grid samples, from 21 J to 26 J (before swelling) and from 15 J to 24 J (after swelling). Flexural tests follow the trends observed by HIT, indicating around 65% higher strength for samples with three metal grid layers vs. samples without a metal grid before water immersion and around 80% higher strength for samples with three metal grid layers vs. samples without a grid after water absorption. The synthesis route, double reinforcing (wood and metal), applied methods of characterization, and optimization according to the obtained results provide a WPC with improved mechanical properties ready for an outdoor purpose.
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- 2023
11. Recirkulacija produkata sagorevanja u proizvodnji silicijuma
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Nedeljković, Dragutin, Stajić-Trošić, Jasna, Grujić, Aleksandar, Milanović, Predrag, Milanović, Jovana, Perišić, Srđan, Nedeljković, Dragutin, Stajić-Trošić, Jasna, Grujić, Aleksandar, Milanović, Predrag, Milanović, Jovana, and Perišić, Srđan
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- 2023
12. Magneto-Mechanical and Thermal Properties of Nd-Fe-B-Epoxy-Bonded Composite Materials
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Grujić, Aleksandar, Nedeljković, Dragutin, Stajić-Trošić, Jasna, Stijepović, Mirko, Alnouri, Sabla, Perišić, Srđan, Grujić, Aleksandar, Nedeljković, Dragutin, Stajić-Trošić, Jasna, Stijepović, Mirko, Alnouri, Sabla, and Perišić, Srđan
- Abstract
Polymer-bonded magnets are a class of composite material that combines the magnetic properties of metal particles and the molding possibility of a polymeric matrix. This class of materials has shown huge potential for various applications in industry and engineering. Traditional research in this field has so far mainly focused on mechanical, electrical or magnetic properties of the composite, or on particle size and distribution. This examination of synthesized Nd-Fe-B-epoxy composite materials includes the mutual comparison of impact toughness, fatigue, and the structural, thermal, dynamic-mechanical, and magnetic behavior of materials with different content of magnetic Nd-Fe-B particles, in a wide range from 5 to 95 wt.%. This paper tests the influence of the Nd-Fe-B content on impacting the toughness of the composite material, as this relationship has not been tested before. The results show that impact toughness decreases, while magnetic properties increase, along with increasing content of Nd-Fe-B. Based on the observed trends, selected samples have been analyzed in terms of crack growth rate behavior. Analysis of the fracture surface morphology reveals the formation of a stable and homogeneous composite material. The synthesis route, the applied methods of characterization and analysis, and the comparison of the obtained results can provide a composite material with optimum properties for a specific purpose.
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- 2023
13. The possibility of the application of the zeolyte powders for the construction of the membranes for the carbon dioxide separation
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Nedeljković Dragutin M., Stevanović Marija P., Stijepović Mirko Z., Stajčić Aleksandar P., Grujić Aleksandar S., Stajić-Trošić Jasna T., and Stevanović Jasmina S.
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mixed matrix membrane ,zeolite ,carbon dioxide separation ,polymer matrix ,membrane selectivity ,Chemical engineering ,TP155-156 ,Chemical industries ,HD9650-9663 - Abstract
The task of this work was to construct the mixed matrix membrane based on polymer that could be used for the treatment of the waste gases. Therefore, high permeability for the carbon dioxide and low permeability for other gases commonly present in the industrial combustion waste gases (nitrogen, oxygen, hydrogen, methane) are essential. Those membranes belong to the group of dense composite membranes, and mechanism for separation is based on the solution-diffusion mechanism. In this paper, feasibility of the application of poly(ethyleneoxid)-copoly(phtalamide) was tested. In order to enchase the permeability of carbon dioxide, three different zeolites were incorporated, and in order to improve compatibility between the inorganic particles and polymer chains, n-tetradecyldimethylamonium bromide (NTAB).was added. Three zeolites were with the 2-dimensional pores (IHW, NSI and TER). The best results in carbon dioxide/hydrogen selectivity were obtained with the membrane constructed with PEBAX 1657 and surface treated zeolites, while the better results concerning selectivity were gained with membranes based on the Polyactive. [Projekat Ministarstva nauke Republike Srbnije, br. TR 34011 i br. III 45019]
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- 2015
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14. The application of the zeolyte powder for the construction of the dense composite membranes for the carbon-dioxide separation
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Nedeljković Dragutin M., Stajčić Aleksandar P., Grujić Aleksandar S., Stijepović Mirko Z., and Stajić-Trošić Jasna T.
- Subjects
mixed matrix membrane ,zeolyte ,carbon dioxide separation ,polymer matrix ,membrane selectivity ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
The main task of the work is to construct the polymeric membrane that could be used for the waste gases treatment. For this purpose, membrane must have high permeability for the carbon dioxide and low permeability of the other gases commonly present in waste gases (hydrogen, oxygen, nitrogen and methane). The constructed membranes were of a dense type, based on a solubility/diffusivity mechanism. In order to enchase the permeability of carbon dioxide, four different zeolytes were added, and in order to improve mechanical stability two different additives were tested. Three zeolytes were with the 3-dimensional pores (ZSM5; Faujasite Linde type A) and one was with the 1-dimensional pores (Linde type L). As an additive, n-tetradecyldimethylamonium bromide - n-C14TMABr was tested. The aim of an additive was to provide good wetting of a highly electrically charged zeolyte particle by the hydrophobic polymer chains. The other examined additive was dimethylaminopyridine (DMAP) which should improve the solubility of carbon dioxide due to its alkali properties. The best results in carbon dioxide/hydrogen selectivity and permeability were obtained with the membrane constructed with PEBAX 1657 and surface treated zeolyte. The obtained permeability of carbon dioxide was 128 Barrer, and the carbon dioxide/hydrogen selectivity was 9.7.
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- 2015
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15. Treatment of Waste Copper Electrolytes Using Insoluble and Soluble Anodes
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Markovic, Radmila, Stevanovic, Jasmina, Gvozdenovic, Milica, Jugovic, Branimir, Grujic, Aleksandar, Nedeljkovic, Dragutin, and Stajic-Trosic, Jasna
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- 2013
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16. Konstrukcija automatizovanog uređaja za određivanje kapilarnosti tekstilnih i kompozitnih materijala primenom „open-source“ principa
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Milanović, Predrag, Grujić, Dragana, Nedeljković, Dragutin, Stanković, Snežana, Novaković, Milada, Milanović, Jovana, Milanović, Predrag, Grujić, Dragana, Nedeljković, Dragutin, Stanković, Snežana, Novaković, Milada, and Milanović, Jovana
- Abstract
Uzimajući u obzir veliki značaj i čestu potrebu za određivanjem kapilarnih svojstava različitih tekstilnih materijala, kao i nedostatke manuelnog određivanja kapilarnosti, i do sada primenjivanjih metoda, ideja autora ovog tehničkog rešenja bila je da se konstruiše uređaj za određivanje kapilarnosti koji je automatizovan dizajniranim softverom prema "open-source" principu, primenom hardvera niske cene i već postojeće laboratorijske opreme: digitalne vage, kompjutera i veb-kamere. Pored opisa uređaja i dizajna softvera pod nazivom „Kapilarko“, u tehničkom rešenju je dato i objašnjenje koraka – obrada slike, određivanje „threshold-a“, određivanje visine napredovanja tečnosti i primena veštačkih neuronskih mreža. Primena dizajniranog automatizovanog uređaja demonstrirana je na određivanju kapilarnosti pletenina različitog sirovinskog sastava. Primenom automatizovanog uređaja za određivanje kapilarnosti tekstilnih i kompozitnih materijala, poboljšan je kvalitat, a istovremeno je i olakšan eksperimentalni rad, u odnosu na manuelno određivanje kapilarnosti. Istražena je i mogućnost korišćenja raspoloživih alata iz oblasti neuronskih mreža za određivanje visine napredovanja tečnosti, prepoznavanjem nakvašenih/mokrih i suvih delova uzoraka, sa ciljem automatskog prepoznavanja visine kapilarnog napredovanja tečnosti na materijalima.
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- 2022
17. Copper-Sulfate Pentahydrate as a Product of the Waste Sulfuric Acid Solution Treatment
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Marković, Radmila, Stevanović, Jasmina, Avramović, Ljiljana, Nedeljković, Dragutin, Jugović, Branimir, Stajić-Trošić, Jasna, and Gvozdenović, Milica
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- 2012
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18. Sinteza, karakterizacija i primena polimernih kompozitnih magnetnih membrana na bazi etilceluloze
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Jančić-Heinemann, Radmila, Putić, Slaviša, Radojević, Vesna, Stajić-Trošić, Jasna, Nedeljković, Dragutin, Stajčić, Aleksandar, Jančić-Heinemann, Radmila, Putić, Slaviša, Radojević, Vesna, Stajić-Trošić, Jasna, Nedeljković, Dragutin, and Stajčić, Aleksandar
- Abstract
Fokus ove doktorske disertacije je na pripremi i karakterizaciji magnetnihnanokompozitnih membrana za separaciju gasova, kao i na pripremi i karakterizacijipolimernih membrana za uklanjanje jona teških metala iz vode. Pri procesiranjumagnetnih membrana, magnetne nanočestice barijum ferita (BaFe12O19) i stroncijumferita (SrFe12O19) inkorporirane su u etilcelulozu, sa ciljem pospešivanja difuzijekiseonika u odnosu na azot. Sinteza asimetričnih polimernih membrana na bazihidrogela ojačanog polietarsulfonom (PES) izvršena je kombinovanjem procesa fazneinverzije sa fotopolimerizacijom i umrežavanjem monomera Ispitivan je uticaj udelananočestica kod magnetnih nanokompozitnih i udela PES kod polimernih membrana namehanička i separaciona svojstva. Sa ciljem identifikacije struktura nastalihprocesiranjem membrana, izvršene su različite analize, kao što su skenirajućaelektronska mikroskopija (FESEM), mikroskopija atomskih sila (AFM), rendgentskodifrakcionaanaliza (XRD) i infracrvena spektroskopija sa Furijeovom transformacijom(FTIR) Mehanička svojstva membrana ispitivana su mikro Vikers metodom izatezanjem. Sorpciona kinetika ispitana je promenom koncentracije jona u rastvoru iopisana je korišćenjem različitih kinetičkih modela. Permeabilnost magnetnihnanokompozitnih membrana ispitana je praćenjem promene izlaznog pritiska smešeazota i kiseonika, kao i čistog azota. Membrane na bazi hidrogelova sa većim sadržajemPES pokazuju poboljšana mehanička svojstva, uz visok adsorpcioni kapacitet.Nanokompozitne magnetne membrane sa većim sadržajem magnetnih nanočesticapokazale su značajno poboljšanje mehaničkih svojstava u poređenju sa čistometilcelulozom, uz visoku permeabilnost. Navedene analize su pokazale da sunanokompozitne membrane na bazi etilceluloze odličan kandidat za separaciju gasova,dok membrane na bazi hidrogelova pokazuju visok potencijal za uklanjanje jona teškihmetala iz vode. Na osnovu dosadašnjih saznanja, navedeni materijali nisu bili predmetranijih istraživanja., The focus of this doctoral dissertation is on the preparation and characterization ofmagnetic nanocomposite membranes for gas separation, as well as on the preparationand characterization of polymer membranes for removal of heavy metal ions fromwater. In the processing of magnetic membranes, magnetic nanoparticles of bariumferrite (BaFe12O19) and strontium ferrite (SrFe12O19) were incorporated intoethylcellulose, in order to promote oxygen diffusion against nitrogen. Synthesis ofasymmetric hydrogel-based polymer membranes reinforced with polyethersulphone(PES) was performed by combining the phase inversion with photopolymerization andthe cross-linking of monomers. The influence of the nanoparticle content in magneticnanocomposite and the PES fraction in polymer membranes on the mechanical andseparation properties was investigated. In order to identify the structures formed bymembrane processing, various analyzes were performed, such as scanning electronmicroscopy (FESEM), atomic force microscopy (AFM), X-ray diffraction XRD andinfrared spectroscopy with Fourier transformation (FTIR). Mechanical properties of themembranes were investigated using micro Vickers method and tensile test. The sorptionkinetics has been followed with the measurements of ions concentration change in thesolution, and was described using different kinetic models. The permeability ofmagnetic nanocomposite membranes was tested by monitoring the output pressurechange of the nitrogen and oxygen mixtures, as well as pure nitrogen. Hydrogel-basedmembranes with a higher PES content showed enhanced mechanical properties, withhigh adsorption capacity. Nanocomposite magnetic membranes with a higher content ofmagnetic nanoparticles have shown a significant improvement in mechanical propertiescompared to pure ethylcellulose, with high permeability. These findings have shownthat nanocomposite membranes based on ethylcellulose are an excellent candidate forgas separation, while hydrogel-based membranes exhi
- Published
- 2018
19. Sinteza, karakterizacija i primena polimernih kompozitnih magnetnih membrana na bazi etilceluloze
- Author
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Jančić-Hajneman, Radmila, Putić, Slaviša, Radojević, Vesna, Stajić-Trošić, Jasna, Nedeljković, Dragutin, Stajčić, Aleksandar P., Jančić-Hajneman, Radmila, Putić, Slaviša, Radojević, Vesna, Stajić-Trošić, Jasna, Nedeljković, Dragutin, and Stajčić, Aleksandar P.
- Abstract
Fokus ove doktorske disertacije je na pripremi i karakterizaciji magnetnih nanokompozitnih membrana za separaciju gasova, kao i na pripremi i karakterizaciji polimernih membrana za uklanjanje jona teških metala iz vode. Pri procesiranju magnetnih membrana, magnetne nanočestice barijum ferita (BaFe12O19) i stroncijum ferita (SrFe12O19) inkorporirane su u etilcelulozu, sa ciljem pospešivanja difuzije kiseonika u odnosu na azot. Sinteza asimetričnih polimernih membrana na bazi hidrogela ojačanog polietarsulfonom (PES) izvršena je kombinovanjem procesa fazne inverzije sa fotopolimerizacijom i umrežavanjem monomera Ispitivan je uticaj udela nanočestica kod magnetnih nanokompozitnih i udela PES kod polimernih membrana na mehanička i separaciona svojstva. Sa ciljem identifikacije struktura nastalih procesiranjem membrana, izvršene su različite analize, kao što su skenirajuća elektronska mikroskopija (FESEM), mikroskopija atomskih sila (AFM), rendgentskodifrakciona analiza (XRD) i infracrvena spektroskopija sa Furijeovom transformacijom (FTIR) Mehanička svojstva membrana ispitivana su mikro Vikers metodom i zatezanjem. Sorpciona kinetika ispitana je promenom koncentracije jona u rastvoru i opisana je korišćenjem različitih kinetičkih modela. Permeabilnost magnetnih nanokompozitnih membrana ispitana je praćenjem promene izlaznog pritiska smeše azota i kiseonika, kao i čistog azota. Membrane na bazi hidrogelova sa većim sadržajem PES pokazuju poboljšana mehanička svojstva, uz visok adsorpcioni kapacitet. Nanokompozitne magnetne membrane sa većim sadržajem magnetnih nanočestica pokazale su značajno poboljšanje mehaničkih svojstava u poređenju sa čistom etilcelulozom, uz visoku permeabilnost. Navedene analize su pokazale da su nanokompozitne membrane na bazi etilceluloze odličan kandidat za separaciju gasova, dok membrane na bazi hidrogelova pokazuju visok potencijal za uklanjanje jona teških metala iz vode. Na osnovu dosadašnjih saznanja, navedeni materijali nisu bili predmet, The focus of this doctoral dissertation is on the preparation and characterization of magnetic nanocomposite membranes for gas separation, as well as on the preparation and characterization of polymer membranes for removal of heavy metal ions from water. In the processing of magnetic membranes, magnetic nanoparticles of barium ferrite (BaFe12O19) and strontium ferrite (SrFe12O19) were incorporated into ethylcellulose, in order to promote oxygen diffusion against nitrogen. Synthesis of asymmetric hydrogel-based polymer membranes reinforced with polyethersulphone (PES) was performed by combining the phase inversion with photopolymerization and the cross-linking of monomers. The influence of the nanoparticle content in magnetic nanocomposite and the PES fraction in polymer membranes on the mechanical and separation properties was investigated. In order to identify the structures formed by membrane processing, various analyzes were performed, such as scanning electron microscopy (FESEM), atomic force microscopy (AFM), X-ray diffraction XRD and infrared spectroscopy with Fourier transformation (FTIR). Mechanical properties of the membranes were investigated using micro Vickers method and tensile test. The sorption kinetics has been followed with the measurements of ions concentration change in the solution, and was described using different kinetic models. The permeability of magnetic nanocomposite membranes was tested by monitoring the output pressure change of the nitrogen and oxygen mixtures, as well as pure nitrogen. Hydrogel-based membranes with a higher PES content showed enhanced mechanical properties, with high adsorption capacity. Nanocomposite magnetic membranes with a higher content of magnetic nanoparticles have shown a significant improvement in mechanical properties compared to pure ethylcellulose, with high permeability. These findings have shown that nanocomposite membranes based on ethylcellulose are an excellent candidate for gas separation, while hydro
- Published
- 2018
20. Adsorption kinetics of polyethersulfone membrane-supported hydrogels
- Author
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Stajčić, Aleksandar, Nedeljković, Dragutin, Panić, Vesna, Radović, Ivana, Grujić, Aleksandar, Stajić-Trošić, Jasna, Jančić-Heinemann, Radmila, Stajčić, Aleksandar, Nedeljković, Dragutin, Panić, Vesna, Radović, Ivana, Grujić, Aleksandar, Stajić-Trošić, Jasna, and Jančić-Heinemann, Radmila
- Abstract
This study presents the route for preparation of the membrane-supporting materials with good mechanical behavior and adsorption properties that provide functionality and are easy to use in various environments. Polyethersulfone (PES) membrane-supported hydrogels were prepared via liquid phase inversion process with photopolymerization and monomer crosslinking. The obtained membranes had asymmetric structure containing dense skin on the top of a porous hydrogel as it is verified by scanning electron microscopy. Software analysis of the pore size revealed that fine pores enabled availability of the membrane active centers to metal cations. The membranes with a higher content of the polymer showed significantly improved mechanical properties compared with commonly used ion exchange membranes, which is crucial for the wastewater treatment application. Adsorption kinetics analysis showed that the hydrogel-rich bottom layer has significantly higher adsorption ability in comparison to the top layer. Adsorption kinetics of the bottom side was described by the first-order kinetics model, whereas for the the top side, phase-boundary controlled reaction model was used.
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- 2018
21. A METHOD FOR DETERMINATION OF SEPARATION PROPERTIES OF MEMBRANES
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Grujić, Aleksandar, primary, Stijepović, Mirko, additional, Stajić Trošić, Jasna, additional, Ilić, Jovana, additional, and Nedeljković, Dragutin, additional
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- 2018
- Full Text
- View/download PDF
22. Mogućnost primene zeolitnih prahova za konstrukciju membrana za izdvajanje ugljen-dioksida
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Nedeljković, Dragutin, Stevanović, Marija P., Stijepović, Mirko Z., Stajčić, Aleksandar, Grujić, Aleksandar, Stajić-Trošić, Jasna, and Stevanović, Jasmina
- Subjects
membrane selectivity ,neporozne membrane ,polimerni matriks ,mixed matrix membrane ,separacija ugljen-dioksida ,polymer matrix ,zeolitni prahovi ,zeolite ,carbon dioxide separation ,selektivnost membrane - Abstract
The aim of this study was to construct a polymer-based mixed matrix membrane that could be used for waste gases treatment. Therefore, high permeability for the carbon dioxide and low permeability for other gases commonly present in the industrial combustion waste gases (nitrogen, oxygen, hydrogen and methane) are essential. These membranes belong to the group of dense composite membranes, whose separation is based on the solution diffusion mechanism. In this paper, feasibility of the application of poly(ethylene oxide)-copoly(phtalamide) was tested. In order to enhance the permeability of carbon dioxide, three different zeolites with two-dimensional pores (IHW, NSI and TER) were incorporated, and in order to improve compatibility between the inorganic particles and polymer chains, n-tetradecyldimethylamonium bromide (NTAB) was added. The best results in carbon dioxide/hydrogen selectivity were obtained with the membrane constructed with PEBAX 1657 and surface treated zeolites, while better results concerning selectivity were gained with membranes based on Polyactive. Cilj ovog rada je bio da se konstruiše neporozna kompozitna membrana bazirana na polimernom matriksu koja može da bude upotrebljena za tretman otpadnih gasova. Za ovu svrhu, neophodno je da membrana ima visoku permeabilnost za ugljen-dioksid i nisku permeabilnost za druge gasove koji ne najčešće sreću u produktima sagorevanja (azot, kiseonik, vodonik, metan). Ove membrane pripadaju grupi neporoznih membrana i mehanizam separacije gasova je baziran na rastvorljivosti i difuziji. U ovom radu, testirana je mogućnost primene poli(etilenoksida)-kopoli(ftalamida). Da bi se povećala permeabilnost ugljen-dioksida, dodavana su tri različita zeolitna praha, a da bi se poboljšala kompatibilnost neorganskih čestica i polimernih lanaca, dodat je n-tetradeciltrimetilamonijum-bromid (NTAB). Ispitivani zeoliti pripadaju grupi sa dvodimenzionalnim porama (IHW, NSI i TER). Najbolji rezultati u separaciji ugljen-dioksida i vodonika su postignuti kod membrana baziranim na polimeru PEBAX 1657 i zeolitima uz dodatak aditiva. Sa druge strane, bolja selektivnost je postignuta kod membrana baziranih na Polyactive polimeru.
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- 2015
23. The possibility of application of zeolyte powders for the construction of membranes for carbon dioxide separation
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Nedeljković, Dragutin M., Stevanović, Marija P., Stijepović, Mirko Z., Stajčić, Aleksandar P., Grujić, Aleksandar S., Stajić-Trošić, Jasna T., and Stevanović, Jasmina S.
- Subjects
membrane selectivity ,mixed matrix membrane ,polymer matrix ,zeolite ,carbon dioxide separation - Abstract
The aim of this study was to construct a polymer-based mixed matrix membrane that could be used for waste gases treatment. Therefore, high permeability for the carbon dioxide and low permeability for other gases commonly present in the industrial combustion waste gases (nitrogen, oxygen, hydrogen and methane) are essential. These membranes belong to the group of dense composite membranes, whose separation is based on the solution diffusion mechanism. In this paper, feasibility of the application of poly(ethylene oxide)-copoly(phtalamide) was tested. In order to enhance the permeability of carbon dioxide, three different zeolites with two-dimensional pores (IHW, NSI and TER) were incorporated, and in order to improve compatibility between the inorganic particles and polymer chains, n-tetradecyldimethylamonium bromide (NTAB) was added. The best results in carbon dioxide/hydrogen selectivity were obtained with the membrane constructed with PEBAX 1657 and surface treated zeolites, while better results concerning selectivity were gained with membranes based on Polyactive.
- Published
- 2015
24. Primena zeolitnih prahova za izradu kompozitnih polimernih membrana za separaciju ugljen-dioksida
- Author
-
Nedeljković, Dragutin, Stajčić, Aleksandar, Grujić, Aleksandar, Stijepović, Mirko Z., and Stajić-Trošić, Jasna
- Subjects
membrane selectivity ,mixed matrix membrane ,separacija ugljen-dioksida ,polymer matrix ,zeolitni prahovi ,polimerna matrica ,zeolyte ,carbon dioxide separation ,kompozitne membrane ,selektivnost membrane - Abstract
The main task of the work is to construct the polymeric membrane that could be used for the waste gases treatment. For this purpose, membrane must have high permeability for the carbon dioxide and low permeability of the other gases commonly present in waste gases (hydrogen, oxygen, nitrogen and methane). The constructed membranes were of a dense type, based on a solubility/diffusivity mechanism. In order to enchase the permeability of carbon dioxide, four different zeolytes were added, and in order to improve mechanical stability two different additives were tested. Three zeolytes were with the 3-dimensional pores (ZSM5; Faujasite Linde type A) and one was with the 1-dimensional pores (Linde type L). As an additive, n-tetradecyldimethylamonium bromide - n-C14TMABr was tested. The aim of an additive was to provide good wetting of a highly electrically charged zeolyte particle by the hydrophobic polymer chains. The other examined additive was dimethylaminopyridine (DMAP) which should improve the solubility of carbon dioxide due to its alkali properties. The best results in carbon dioxide/hydrogen selectivity and permeability were obtained with the membrane constructed with PEBAX 1657 and surface treated zeolyte. The obtained permeability of carbon dioxide was 128 Barrer, and the carbon dioxide/hydrogen selectivity was 9.7. Cilj istraživanja prikazanih u ovom radu je izrada polimerne membrane koja bi imala primenu u prečišćavanju otpadnih gasova. Membrana konstruisana za ovu primenu bi morala da ima visoku permeabilnost za ugljen-dioksid i nisku permeabilnost za druge gasove koji su standardno prisutni u otpadnim gasovima (vodonik, kiseonik, azot i metan). Dobijene membrane pripadaju tipu neporoznih membrana čija se permeabilnost bazira na mehanizmu rastvaranja i difuzije. U ovom radu, ispitivana je mogućnost primene poli(etilenoksida) - kopoli(ftalamida) za ovu svrhu. Da bi se povećala permeabilnost ugljen-dioksida, dodate su četiri različite vrste zeolitnih prahova, a u cilju poboljšanja mehaničkih svojstava, ispitivana su dva aditiva. Tri zeolitna praha korišćena u eksperimentu imaju trodimenzionalne pore (ZSM5, Faujasit i Linde zeolit tip A), a jedan prah je sa jednodimenzionalnim porama (Linde zeolit tip L). Kao aditiv je testiran n-tetradeciltrimetilamonijum bromid. Cilj dodavanja ovog aditiva je da omogući dobar kontakt između dugih, hidrofobnih polimernih lanaca i naelektrisanih čestica zeolita. Drugi ispitivani aditiv je dimetilaminopiridin, čija bi bazna svojstva trebalo da poboljšaju rastvorljovost ugljen dioksida. Najbolji rezultati su postignuti korišćenjem membrane konstruisane sa PEBAX 1657 polimerom i zeolitom u prisustvu aditiva.
- Published
- 2015
25. Gas Separation Properties of the Dense Polymer-Zeolite Powder Composite Membranes
- Author
-
Brkic, Dominik, Nedeljković, Dragutin, Putić, Lana, Stajić-Trošić, Jasna, Stamenovic, Marina, Brkic, Dominik, Nedeljković, Dragutin, Putić, Lana, Stajić-Trošić, Jasna, and Stamenovic, Marina
- Abstract
The natural balance in the Earth's atmosphere is significantly influenced by the human emission of the combustion products, mainly carbon dioxide. Therefore, strong efforts are directed in the direction of the reduction of that emission. The solution might be searched in the direction of the construction of the membrane that would be highly transparent to the carbon dioxide, but not transparent to the other gases commonly present in the waste gases (oxygen, nitrogen, hydrogen, methane). One of the feasible designs for this purpose is dense, non-porous membranes, with zeolite particles dispersed in the polymer matrix. Zeolite particles should increase the solubility of the carbon dioxide, and thus enhance its permeability. In this paper, the possibility of application of polyether-b-amide (with 60% of PEG) as a polymer matrix was tested. For the inorganic component, four different zeolite types with three different pore geometries were tested. The influence of the additive which was added in order to provide good contact between the highly polar and charged zeolite inorganic particle, and hydrophobic polymer chains was also tested.
- Published
- 2016
26. Magnetno ponašanje hibridnih magnetnih kompozitnih materijala
- Author
-
Stajić-Trošić, Jasna, Grujić, Aleksandar, Stijepović, Mirko Z., Nedeljković, Dragutin, Stajčić, Aleksandar, and Žak, Tomas
- Subjects
bonded magneti ,VSM ,kompozitni materijali ,composite materials ,Nd-Fe-B ,bonded magnets - Abstract
Polymer bonded magnets are contemporary materials with a very large range of applications. The objective of this study is to assess how different content of Nd-Fe-B and/or barium ferrite particles affect on magnetic and morphological properties of bonded composite materials. Interactions between employed magnetic powders and interactions between magnetic powders and polymer binder are considered. For examination of the magnetic behavior Vibrating Sample Magnetometer (VSM) is used. Different shape and size of obtained hysteresis loops are used for comparison and prediction of polymer bonded materials properties. Polimerom vezani magneti predstavljaju savremene materijale sa veoma širokim spektrom primene. Cilj ovog rada je da se analizira i prikaže kako različiti udeli čestica Nd-Fe-B i/ili barijum ferita utiču na magnetna i morfološka svojstva bonded kompozitnih materijala. Razmatrane su interakcije između primenjenih magnetnih prahova različitog tipa i interakcije između magnetnih prahova i polimerne matrice. Za merenje magnetnih svojstava kompozita korišćen je vibracioni magnetometar (VSM). Različiti oblici i veličine dobijenih histerezisnih petlji su poređeni i analizirani u cilju predviđanja magnetnog ponašanja kompozita.
- Published
- 2014
27. The possibility of application of zeolyte powders for the construction of membranes for carbon dioxide separation
- Author
-
Nedeljković, Dragutin, Stevanović, Marija P., Stijepović, Mirko, Stajčić, Aleksandar, Grujić, Aleksandar, Stajić-Trošić, Jasna, Stevanović, Jasmina, Nedeljković, Dragutin, Stevanović, Marija P., Stijepović, Mirko, Stajčić, Aleksandar, Grujić, Aleksandar, Stajić-Trošić, Jasna, and Stevanović, Jasmina
- Abstract
The aim of this study was to construct a polymer-based mixed matrix membrane that could be used for waste gases treatment. Therefore, high permeability for the carbon dioxide and low permeability for other gases commonly present in the industrial combustion waste gases (nitrogen, oxygen, hydrogen and methane) are essential. These membranes belong to the group of dense composite membranes, whose separation is based on the solutiondiffusion mechanism. In this paper, feasibility of the application of poly(ethylene oxide)-copoly(phtalamide) was tested. In order to enhance the permeability of carbon dioxide, three different zeolites with two-dimensional pores (IHW, NS/ and TER) were incorporated, and in order to improve compatibility between the inorganic particles and polymer chains, n-tetradecyldimethylamonium bromide (NTAB) was added. The best results in carbon dioxide/hydrogen selectivity were obtained with the membrane constructed with PEBAX 1657 and surface treated zeolites, while better results concerning selectivity were gained with membranes based on Polyactive.
- Published
- 2015
28. The application of the zeolyte powder for the construction of the dense composite membranes for the carbon-dioxide separation
- Author
-
Nedeljković, Dragutin, Stajčić, Aleksandar, Grujić, Aleksandar, Stijepović, Mirko, Stajić-Trošić, Jasna, Nedeljković, Dragutin, Stajčić, Aleksandar, Grujić, Aleksandar, Stijepović, Mirko, and Stajić-Trošić, Jasna
- Abstract
The main task of the work is to construct the polymeric membrane that could be used for the waste gases treatment. For this purpose, membrane must have high permeability for the carbon dioxide and low permeability of the other gases commonly present in waste gases (hydrogen, oxygen, nitrogen and methane). The constructed membranes were of a dense type, based on a solubility/diffusivity mechanism. In order to enchase the permeability of carbon dioxide, four different zeolytes were added, and in order to improve mechanical stability two different additives were tested. Three zeolytes were with the 3-dimensional pores (ZSM5; Faujasite Linde type A) and one was with the 1-dimensional pores (Linde type L). As an additive, n-tetradecyldimethylamonium bromide - n-C14TMABr was tested. The aim of an additive was to provide good wetting of a highly electrically charged zeolyte particle by the hydrophobic polymer chains. The other examined additive was dimethylaminopyridine (DMAP) which should improve the solubility of carbon dioxide due to its alkali properties. The best results in carbon dioxide/hydrogen selectivity and permeability were obtained with the membrane constructed with PEBAX 1657 and surface treated zeolyte. The obtained permeability of carbon dioxide was 128 Barrer, and the carbon dioxide/hydrogen selectivity was 9.7., Cilj istraživanja prikazanih u ovom radu je izrada polimerne membrane koja bi imala primenu u prečišćavanju otpadnih gasova. Membrana konstruisana za ovu primenu bi morala da ima visoku permeabilnost za ugljen-dioksid i nisku permeabilnost za druge gasove koji su standardno prisutni u otpadnim gasovima (vodonik, kiseonik, azot i metan). Dobijene membrane pripadaju tipu neporoznih membrana čija se permeabilnost bazira na mehanizmu rastvaranja i difuzije. U ovom radu, ispitivana je mogućnost primene poli(etilenoksida) - kopoli(ftalamida) za ovu svrhu. Da bi se povećala permeabilnost ugljen-dioksida, dodate su četiri različite vrste zeolitnih prahova, a u cilju poboljšanja mehaničkih svojstava, ispitivana su dva aditiva. Tri zeolitna praha korišćena u eksperimentu imaju trodimenzionalne pore (ZSM5, Faujasit i Linde zeolit tip A), a jedan prah je sa jednodimenzionalnim porama (Linde zeolit tip L). Kao aditiv je testiran n-tetradeciltrimetilamonijum bromid. Cilj dodavanja ovog aditiva je da omogući dobar kontakt između dugih, hidrofobnih polimernih lanaca i naelektrisanih čestica zeolita. Drugi ispitivani aditiv je dimetilaminopiridin, čija bi bazna svojstva trebalo da poboljšaju rastvorljovost ugljen dioksida. Najbolji rezultati su postignuti korišćenjem membrane konstruisane sa PEBAX 1657 polimerom i zeolitom u prisustvu aditiva.
- Published
- 2015
29. A method for determination of separation properties of membranes
- Author
-
Grujić, Aleksandar, Stijepović, Mirko, Stajić-Trošić, Jasna, Ilić, J., Nedeljković, Dragutin, Grujić, Aleksandar, Stijepović, Mirko, Stajić-Trošić, Jasna, Ilić, J., and Nedeljković, Dragutin
- Abstract
In this study, design of lab scale device for determination of separation properties of membranes is presented and analyzed. Device operates with different gas pressure between chambers, whereby gas streams perpendicular to the membrane. Using appropriate acquisition system and applying mathematical formulas, mechanism for gas transfer through the membrane is determinate. Polymer membranes based on zeolite are synthesized and tested by lab scale device. The membranes with various content of zeolite are tested with CO2 gas until optimal composition of membrane components is established. Beside good mechanical and structural properties of applied membrane, suitable values of permeability with good agreement with the literature data are obtained., U ovom radu je prikazano i analizirano konstrukcijsko rešenje laboratorijskog uređaja za određivanje separacionih svojstava membrana. Rad uređaja je baziran na razlici pritisaka između komora, pri čemu gas struji normalno na poprečni presek membrana. Odgovarajućim sistemom za akviziciju podataka i primenom odgovarajućih matematičkih formula određen je mehanizam prenosa kroz membranu. Polimerne membrane na bazi zeolita su sintetizovane i testirane na uređaju. Membrane sa različitim udelim zeolita su testirane na CO2 gas, dok nije ustanovljen optimalan sastav komponenti za sintezu membrana.Pored dobrih mehaničkih i strukturnih svojstava testirane membrane, dobijene su zadovoljavajuće vrednosti permeabilnosti koje su u saglasnosti sa drugim autorima.
- Published
- 2015
30. Polimerni magnetni kompoziti na bazi Nd-Fe-B
- Author
-
Grujić, Aleksandar, Stajić-Trošić, Jasna, Stijepović, Mirko Z., Nedeljković, Dragutin, Stajčić, Aleksandar, and Stevanović, Jasmina
- Subjects
Condensed Matter::Soft Condensed Matter ,Bonded Magnet ,Composite ,Nd-Fe-B ,DMA ,Kompozit - Abstract
Various types and contents of magnetic powder and polymer matrix induce different mechanical, magnetic, electrical and optical properties of final composite material. The strong influence of relatively small amounts of filler particles on the dynamic mechanical properties of polymers has significantly contributed to increased use of polymer materials in many commercial applications. The higher content of magnetic filler has direct influence on magnetic properties of composites, but also may change the rheology of polymer melt during process and, subsequently, impact the mechanical strength of bonded magnets. For better insight into viscoelastic behaviour of composites, beside experiments, a theory that explicitly takes the shape factor, particle distribution, particle-particle interactions as well as particle-polymer matrix interactions into account is required. The mathematical prediction of storage modulus behaviour is examined. The several proposed analytical models are tested versus experimental results. Some of applied models agree very well with experimental data, whilst others deviate significantly. Različite vrste primenjenih magnetnih prahova i polimerne matrice, kao i njihovi udeli, utiču na mehanička, magnetna, električna i optička svojstva finalnog kompozitnog materijala. Veliki uticaj relativno malih udela čestica punioca na dinamičko mehanička svojstva polimera značajno doprinosi većoj komercijalnoj upotrebi kompozitnih materijala. Veliki udeli magnetnog praha u mnogome utiču na magnetna svojstva kompozita, ali takođe mogu dovesti do reoloških promena u polimeru tokom procesa topljenja, što ima direktan uticaj na mehanička svojstva polimerom vezanih (bonded) magneta. Radi boljeg uvida u visokoelastična svojstva kompozita, osim eksperimenata, neophodno je uzeti u obzir i teorijska razmatranja koja eksplicitno objašnjavaju uticaj faktora oblika, raspodelu čestica, interakcije između čestica, kao i interakcije između čestica i polimera. U tom smislu vršeno je i matematičko predviđanje ponašanja modula uskladištene energije (E') kompozita. Nekoliko predloženih analitičkih modela su testirani i upoređeni sa eksperimentalnim rezultatima. Neki od primenjenih modela se veoma dobro slažu sa dobijenim eksperimentalnim rezultatima, dok neki značajno odstupaju.
- Published
- 2013
31. The application of zeolite nanopowder for the construction of the dense composite polymer membranes for carbon dioxide separation
- Author
-
Nedeljković, Dragutin, Stajčić, Aleksandar, Grujić, Aleksandar, Stajić-Trošić, Jasna, Zrilić, Milorad, Stevanović, Jasmina, and Drmanić, Saša Ž.
- Subjects
Carbon dioxide separation ,Zeolite ,Mixed matrix membrane ,Polymer matrix ,Membrane selectivity - Abstract
The main task of the work is to construct the polymeric membrane that could be used for the waste gases treatment. For this purpose, membrane must have high permeability for the carbon dioxide and low permeability of the other gases commonly present in waste gases (hydrogen, oxygen, nitrogen and methane). The constructed membranes were of a dense type, based on a solubility/diffusivity mechanism. In this paper, feasibility of the application of poly(ethyleneoxid)-copoly(phtalamide) was tested. In order to enchase the permeability of carbon dioxide, four different zeolites were added, and in order to improve mechanical stability two different additives were tested. Three zeolites were with the 3-dimensional pores (ZSM5; Faujasite Linde type A) and one was with the 1-dimensional pores (Linde type L). As an additive, n-tetradecyldimethylamonium bromide - n-C14TMABr was tested. The aim of an additive was to provide good wetting of a highly electrically charged zeolite particle by the hydrophobic polymer chains. The other examined additive was dimethylaminopyridine (DMAP) which should improve the solubility of carbon dioxide due to its alkali properties. The best results in carbon dioxide/hydrogen selectivity and permeability were obtained with the membrane constructed with PEBAX 1657 and surface treated zeolite.
- Published
- 2012
32. Dynamic Mechanical Behaviour of Polymer Bonded Nd-Fe-B Composite Materials
- Author
-
Grujić, Aleksandar, Stijepović, Mirko Z., Stajić-Trošić, Jasna, Putic, Slavisa, Nedeljković, Dragutin, Stajčić, Aleksandar, and Aleksić, Radoslav
- Subjects
super quantum interference device (SQUID) ,composite materials ,neodymium-iron boron ,dynamic mechanical analysis (DMA) ,epoxy resin - Abstract
Magnetic composite materials with varied content of Nd-Fe-B particles in epoxy matrix are examined from a dynamic mechanical perspective. Structural, viscoelastic and magnetic properties of composites have been observed using Scanning Electron Microscope (SEM), Dynamic Mechanical Analysis (DMA) and Super Quantum Interference Device (SQUID) magnetometer, respectively. Experimental results show that magnetic properties and corresponding dynamic mechanical behaviour depend on packing density. Also, results observed by predictive mathematical models suggest that maximal packing factor has a direct impact on elastic behaviour of composites. [doi:10.2320/matertrans.M2011218]
- Published
- 2012
33. Magnetic behaviour of hybrid magnetic composite materials
- Author
-
Stajić-Trošić, Jasna, Grujić, Aleksandar, Stijepović, Mirko Z., Nedeljković, Dragutin, Stajčić, Aleksandar, Žak, Tomas, Stajić-Trošić, Jasna, Grujić, Aleksandar, Stijepović, Mirko Z., Nedeljković, Dragutin, Stajčić, Aleksandar, and Žak, Tomas
- Abstract
Polymer bonded magnets are contemporary materials with a very large range of applications. The objective of this study is to assess how different content of Nd-Fe-B and/or barium ferrite particles affect on magnetic and morphological properties of bonded composite materials. Interactions between employed magnetic powders and interactions between magnetic powders and polymer binder are considered. For examination of the magnetic behavior Vibrating Sample Magnetometer (VSM) is used. Different shape and size of obtained hysteresis loops are used for comparison and prediction of polymer bonded materials properties., Polimerom vezani magneti predstavljaju savremene materijale sa veoma širokim spektrom primene. Cilj ovog rada je da se analizira i prikaže kako različiti udeli čestica Nd-Fe-B i/ili barijum ferita utiču na magnetna i morfološka svojstva bonded kompozitnih materijala. Razmatrane su interakcije između primenjenih magnetnih prahova različitog tipa i interakcije između magnetnih prahova i polimerne matrice. Za merenje magnetnih svojstava kompozita korišćen je vibracioni magnetometar (VSM). Različiti oblici i veličine dobijenih histerezisnih petlji su poređeni i analizirani u cilju predviđanja magnetnog ponašanja kompozita.
- Published
- 2014
34. Evolution of microstructure of melt-spun Nd-Fe-B alloy with low Nd content during the heat treatment
- Author
-
Talijan, Nadežda M., Stajić-Trošić, Jasna, Ćosović, Vladan, Grujić, Aleksandar, Nedeljković, Dragutin, and Žak, Tomas
- Subjects
melt-spun Nd-Fe-B ,phase transformation ,heat treatment ,XRD ,SEM ,MS ,DTA ,EDS - Abstract
In order to examine and study evolution of microstructure during the phase transformations for applied heat treatment regime for achieving the optimal values of magnetic properties of the investigated melt-spun Nd-Fe-B alloy with low Nd content were using different techniques and methods including SEM with EDS, DTA, XRD, MS analysis and magnetic measurements also.
- Published
- 2004
35. Polymer bonded magnetic composites based on Nd-Fe-B
- Author
-
Grujić, Aleksandar, Stajić-Trošić, Jasna, Stijepović, Mirko, Nedeljković, Dragutin, Stajčić, Aleksandar, Stevanović, Jasmina, Grujić, Aleksandar, Stajić-Trošić, Jasna, Stijepović, Mirko, Nedeljković, Dragutin, Stajčić, Aleksandar, and Stevanović, Jasmina
- Abstract
Various types and contents of magnetic powder and polymer matrix induce different mechanical, magnetic, electrical and optical properties of final composite material. The strong influence of relatively small amounts of filler particles on the dynamic mechanical properties of polymers has significantly contributed to increased use of polymer materials in many commercial applications. The higher content of magnetic filler has direct influence on magnetic properties of composites, but also may change the rheology of polymer melt during process and, subsequently, impact the mechanical strength of bonded magnets. For better insight into viscoelastic behaviour of composites, beside experiments, a theory that explicitly takes the shape factor, particle distribution, particle-particle interactions as well as particle-polymer matrix interactions into account is required. The mathematical prediction of storage modulus behaviour is examined. The several proposed analytical models are tested versus experimental results. Some of applied models agree very well with experimental data, whilst others deviate significantly., Različite vrste primenjenih magnetnih prahova i polimerne matrice, kao i njihovi udeli, utiču na mehanička, magnetna, električna i optička svojstva finalnog kompozitnog materijala. Veliki uticaj relativno malih udela čestica punioca na dinamičko mehanička svojstva polimera značajno doprinosi većoj komercijalnoj upotrebi kompozitnih materijala. Veliki udeli magnetnog praha u mnogome utiču na magnetna svojstva kompozita, ali takođe mogu dovesti do reoloških promena u polimeru tokom procesa topljenja, što ima direktan uticaj na mehanička svojstva polimerom vezanih (bonded) magneta. Radi boljeg uvida u visokoelastična svojstva kompozita, osim eksperimenata, neophodno je uzeti u obzir i teorijska razmatranja koja eksplicitno objašnjavaju uticaj faktora oblika, raspodelu čestica, interakcije između čestica, kao i interakcije između čestica i polimera. U tom smislu vršeno je i matematičko predviđanje ponašanja modula uskladištene energije (E') kompozita. Nekoliko predloženih analitičkih modela su testirani i upoređeni sa eksperimentalnim rezultatima. Neki od primenjenih modela se veoma dobro slažu sa dobijenim eksperimentalnim rezultatima, dok neki značajno odstupaju.
- Published
- 2013
36. The effect of oxidants through a tailing dump depth and the leaching of copper
- Author
-
Stevanović, Zoran, Antonijević, Milan D., Bogdanović, Grozdanka, Bugarin, Mile, Trujic, Vlastimir, Marković, Radmila, Nedeljković, Dragutin, Stevanović, Zoran, Antonijević, Milan D., Bogdanović, Grozdanka, Bugarin, Mile, Trujic, Vlastimir, Marković, Radmila, and Nedeljković, Dragutin
- Abstract
The research results of the oxidants influence on Cu leaching recovery from the old Bor flotation tailing dump from the Bor mining facilities, located in eastern Serbia, will be present. Leaching experiments were carried out on samples of tailings taken from the surface of tailing dump down to the depth of 20 m, per depth intervals of 5 m. Copper content in the initial samples ranged from 0.026 % (surface) to 0.43% (20 m depth). Tests of copper leaching were carried out in the acid media (0.01 M solution of H2SO4) without an oxidant, with addition of hydrogen peroxide and oxygen. All three combinations of tests were done with and without the previous rinsing of samples so that total of six different series of experiments emerged. During previous rinsing of samples with distilled water, high degree of copper leaching (up to 75.33%) was achieved in some samples indicating the presence of copper sulfate and other soluble copper oxides. The highest copper recovery were obtained in the experiments with 3% solution of hydrogen peroxide and amounted to 88.93% and 62.63% for samples with and without rinsing, respectively. These results indicate on extremely high mobility of copper ions and the risk in terms of pollution the surrounding water system and soil.
- Published
- 2013
37. Using the Low-Cost Waste Materials for Heavy Metals Removal from the Mine Wastewater
- Author
-
Marković, Radmila, Stevanović, Jasmina, Stevanović, Zoran, Bugarin, Mile, Nedeljković, Dragutin, Grujić, Aleksandar, Stajić-Trošić, Jasna, Marković, Radmila, Stevanović, Jasmina, Stevanović, Zoran, Bugarin, Mile, Nedeljković, Dragutin, Grujić, Aleksandar, and Stajić-Trošić, Jasna
- Abstract
The possibility of application of low-cost and easily available materials such as cardboard or sawdust for the heavy metals removal from the acid mine water was investigated. The sawdust was obtained from oak and fir-wood. Those materials were tested on the real acid mine wastewater that contained copper, iron, zinc, nickel, and manganese in the concentrations above the maximal allowed level. The adsorption degrees of those elements were investigated. The results were shown that the iron was mechanically removed. The results of chemical analysis of effluent obtained by the use of sawdust from fir-wood indicate that the values for iron and nickel ions were lower than allowed values by the legislative direction. The highest value for copper adsorption degree of 98.31% was achieved at pH value of 7.94. Content of manganese in the effluent and at the end of process, was near the initial value. Using the sawdust obtained from oak as the adsorption material, zinc and manganese concentration in the effluent was near the start values and copper and iron content was decreased but the values were higher than allowed. Using the cardboard, the copper adsorption degree was up to 95 mass%, iron content was under the limit value for the applied chemical detection method. The content of the manganese was not changed and the content of the zinc was decreased but the concentration was over the maximum allowed value. [doi:10.2320/matertrans.M2011191]
- Published
- 2011
38. Influence of composition of the magnetic composite coating on the performance of the optical fiber magnetic field sensing element
- Author
-
Radojević, Vesna, Nedeljković, Dragutin, Grujić, Aleksandar, Talijan, Nadežda M., Ćosović, Vladan, Aleksić, Radoslav, Radojević, Vesna, Nedeljković, Dragutin, Grujić, Aleksandar, Talijan, Nadežda M., Ćosović, Vladan, and Aleksić, Radoslav
- Abstract
The optical fiber magnetic sensing element (OFMSE) based on the optical fiber coated with composite coating polymermagnetic powder has been already introduced in magnetic field sensing. In this research, the rapid quenched Nd-Fe-B powder with Nd rich content was used as magneto-active component in composite coating. Magnetic powder was dispersed in poly-(ethylene-co-vinyl- acetate) - EVA solution in toluene. The influence of magnetic powder content (20, 30, 40 and 50 mass %) in composite coating of multimode optical fiber on the thickness, hardness and uniformity was observed and discussed. Sensitivity and reversibility of the constructed OFMSE in the external magnetic field are illustrated.
- Published
- 2007
39. Application of permanent magnetic powder for magnetic field sensing elements
- Author
-
Nedeljković, Dragutin, Radojević, Vesna, Ćosović, Vladan, Serbez, Tatjana, Talijan, Nadezda, Aleksić, Radoslav, Nedeljković, Dragutin, Radojević, Vesna, Ćosović, Vladan, Serbez, Tatjana, Talijan, Nadezda, and Aleksić, Radoslav
- Abstract
A multimode optical fiber with a composite polymer-magnetic coating was investigated as an optical fiber magnetic sensing element (OFMSE) for detecting external magnetic fields. The coating was formed by dispersing the magnetic powder Nd-Fe-B in poly-(ethylene-co-vinyl acetate)-EVA solution in toluene. The influence of an applied magnetic field on the change in intensity of a light signal propagated through the OFMSE constructed was investigated. In this study, the influence of the magnetic powder concentration in the composite coating on optical propagation characteristics of the modified optical fiber with the composite polymer-magnetic coating was investigated.
- Published
- 2006
40. The influence of concentration of Nd-Fe-B powder in composite coating of optical fiber to the sensibility to external magnetic field
- Author
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Radojević, Vesna, Serbez, T., Aleksić, Radoslav, Nedeljković, Dragutin, Brajović, Ljiljana, Radojević, Vesna, Serbez, T., Aleksić, Radoslav, Nedeljković, Dragutin, and Brajović, Ljiljana
- Abstract
Multi-mode optical fiber with magnetic composite coating was investigated as an optical fiber sensor element (OFMSE) for magnetic field sensing The composite coating was formed with dispersions of permanent magnet powder of Nd-Fe-B in poly (ethylene-co-vinyl acetate)-EVA solutions in toluene. The influence of the applied external magnetic field on the change of intensity of the light signal propagate trough developed optical fibers sensor element was investigated. In this paper the influence of the content of magnetic powder in the composite coating on the optical propagation characteristics of optical fiber were particularly investigated.
- Published
- 2005
41. Dynamic Mechanical Behaviour of Polymer Bonded Nd–Fe–B Composite Materials
- Author
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Grujić, Aleksandar, primary, Stijepović, Mirko, additional, Stajić-Trošić, Jasna, additional, Putić, Slaviša, additional, Nedeljković, Dragutin, additional, Stajčić, Aleksandar, additional, and Aleksić, Radoslav, additional
- Published
- 2012
- Full Text
- View/download PDF
42. Optical fibers with composite magnetic coating for magnetic field sensing
- Author
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Radojević, Vesna, Nedeljković, Dragutin, Talijan, Nadežda, Trifunović, Dejan, Aleksić, Radoslav, Radojević, Vesna, Nedeljković, Dragutin, Talijan, Nadežda, Trifunović, Dejan, and Aleksić, Radoslav
- Abstract
The investigated system for optical fiber sensor was multi-mode optical fiber with magnetic composite coating. Polymer component of composite coating was poly (ethylene-co-vinyl acetate)-EVA, and the magnetic component was powder of SmCo5 permanent magnet in form of single domain particles. The influence of the applied external magnetic field on the change of intensity of the light signal propagated through optical fiber was investigated.
- Published
- 2004
43. THE APPLICATION OF ZEOLITE NANOPOWDER FOR THE CONSTRUCTION OF THE DENSE COMPOSITE POLYMER MEMBRANES FOR CARBON DIOXIDE SEPARATION.
- Author
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Nedeljković, Dragutin M., Stajčić, Aleksandar P., Grujić, Aleksandar S., Stajić-Trošić, Jasna T., Zrilić, Milorad M., Stevanovć, Jasmina S, and Drmanić, Sasa Z.
- Subjects
- *
WASTE gases , *PERMEABILITY , *CARBON dioxide , *SOLUBILITY , *ZEOLITES - Abstract
The main task of the work is to construct the polymeric membrane that could be used for the waste gases treatment. For this purpose, membrane must have high permeability for the carbon dioxide and low permeability of the other gases commonly present in waste gases (hydrogen, oxygen, nitrogen and methane). The constructed membranes were of a dense type, based on a solubility/diffusivity mechanism. In this paper, feasibility of the application of poly(ethyleneoxid)-copoly(phtalamide) was tested. In order to enchase the permeability of carbon dioxide, four different zeolites were added, and in order to improve mechanical stability two different additives were tested. Three zeolites were with the 3- dimensional pores (ZSM5; Faujasite Linde type A) and one was with the 1-dimensional pores (Linde type L). As an additive, n-tetradecyldimethylamonium bromide - n- C14TMABr was tested. The aim of an additive was to provide good wetting of a highly electrically charged zeolite particle by the hydrophobic polymer chains. The other examined additive was dimethylaminopyridine (DMAP) which should improve the solubility of carbon dioxide due to its alkali properties. The best results in carbon dioxide/hydrogen selectivity and permeability were obtained with the membrane constructed with PEBAX 1657 and surface treated zeolite [ABSTRACT FROM AUTHOR]
- Published
- 2012
44. Sinteza, karakterizacija i primena polimernih kompozitnih magnetnih membrana na bazi etilceluloze
- Author
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Stajčić, Aleksandar P., Jančić-Hajneman, Radmila, Putić, Slaviša, Radojević, Vesna, Stajić-Trošić, Jasna, and Nedeljković, Dragutin
- Subjects
separacija gasova ,adsorpcija ,uklanjanje jona teških metala ,mechanical properties ,polymer nanocomposites ,membranes ,adsorption ,mehanička svojstva ,polimerni nanokompoziti ,propustljivost ,permeability ,gas separation ,membrane ,removal of heavy metal ions - Abstract
Fokus ove doktorske disertacije je na pripremi i karakterizaciji magnetnih nanokompozitnih membrana za separaciju gasova, kao i na pripremi i karakterizaciji polimernih membrana za uklanjanje jona teških metala iz vode. Pri procesiranju magnetnih membrana, magnetne nanočestice barijum ferita (BaFe12O19) i stroncijum ferita (SrFe12O19) inkorporirane su u etilcelulozu, sa ciljem pospešivanja difuzije kiseonika u odnosu na azot. Sinteza asimetričnih polimernih membrana na bazi hidrogela ojačanog polietarsulfonom (PES) izvršena je kombinovanjem procesa fazne inverzije sa fotopolimerizacijom i umrežavanjem monomera Ispitivan je uticaj udela nanočestica kod magnetnih nanokompozitnih i udela PES kod polimernih membrana na mehanička i separaciona svojstva. Sa ciljem identifikacije struktura nastalih procesiranjem membrana, izvršene su različite analize, kao što su skenirajuća elektronska mikroskopija (FESEM), mikroskopija atomskih sila (AFM), rendgentskodifrakciona analiza (XRD) i infracrvena spektroskopija sa Furijeovom transformacijom (FTIR) Mehanička svojstva membrana ispitivana su mikro Vikers metodom i zatezanjem. Sorpciona kinetika ispitana je promenom koncentracije jona u rastvoru i opisana je korišćenjem različitih kinetičkih modela. Permeabilnost magnetnih nanokompozitnih membrana ispitana je praćenjem promene izlaznog pritiska smeše azota i kiseonika, kao i čistog azota. Membrane na bazi hidrogelova sa većim sadržajem PES pokazuju poboljšana mehanička svojstva, uz visok adsorpcioni kapacitet. Nanokompozitne magnetne membrane sa većim sadržajem magnetnih nanočestica pokazale su značajno poboljšanje mehaničkih svojstava u poređenju sa čistom etilcelulozom, uz visoku permeabilnost. Navedene analize su pokazale da su nanokompozitne membrane na bazi etilceluloze odličan kandidat za separaciju gasova, dok membrane na bazi hidrogelova pokazuju visok potencijal za uklanjanje jona teških metala iz vode. Na osnovu dosadašnjih saznanja, navedeni materijali nisu bili predmet ranijih istraživanja. The focus of this doctoral dissertation is on the preparation and characterization of magnetic nanocomposite membranes for gas separation, as well as on the preparation and characterization of polymer membranes for removal of heavy metal ions from water. In the processing of magnetic membranes, magnetic nanoparticles of barium ferrite (BaFe12O19) and strontium ferrite (SrFe12O19) were incorporated into ethylcellulose, in order to promote oxygen diffusion against nitrogen. Synthesis of asymmetric hydrogel-based polymer membranes reinforced with polyethersulphone (PES) was performed by combining the phase inversion with photopolymerization and the cross-linking of monomers. The influence of the nanoparticle content in magnetic nanocomposite and the PES fraction in polymer membranes on the mechanical and separation properties was investigated. In order to identify the structures formed by membrane processing, various analyzes were performed, such as scanning electron microscopy (FESEM), atomic force microscopy (AFM), X-ray diffraction XRD and infrared spectroscopy with Fourier transformation (FTIR). Mechanical properties of the membranes were investigated using micro Vickers method and tensile test. The sorption kinetics has been followed with the measurements of ions concentration change in the solution, and was described using different kinetic models. The permeability of magnetic nanocomposite membranes was tested by monitoring the output pressure change of the nitrogen and oxygen mixtures, as well as pure nitrogen. Hydrogel-based membranes with a higher PES content showed enhanced mechanical properties, with high adsorption capacity. Nanocomposite magnetic membranes with a higher content of magnetic nanoparticles have shown a significant improvement in mechanical properties compared to pure ethylcellulose, with high permeability. These findings have shown that nanocomposite membranes based on ethylcellulose are an excellent candidate for gas separation, while hydrogel-based membranes exhibit high potential for removal of heavy metal ions from water. Based on our current knowledge, these materials have not been the subject of previous research.
- Published
- 2018
45. Synthesis and characterization of ethylcellulose polymer composite magnetic membranes
- Author
-
Stajčić, Aleksandar, Jančić-Heinemann, Radmila, Putić, Slaviša, Radojević, Vesna, Stajić-Trošić, Jasna, and Nedeljković, Dragutin
- Subjects
separacija gasova ,adsorpcija ,uklanjanje jona teških metala ,mechanical properties ,polymer nanocomposites ,membranes ,adsorption ,mehanička svojstva ,polimerni nanokompoziti ,propustljivost ,permeability ,gas separation ,membrane ,removal of heavy metal ions - Abstract
Fokus ove doktorske disertacije je na pripremi i karakterizaciji magnetnihnanokompozitnih membrana za separaciju gasova, kao i na pripremi i karakterizacijipolimernih membrana za uklanjanje jona teških metala iz vode. Pri procesiranjumagnetnih membrana, magnetne nanočestice barijum ferita (BaFe12O19) i stroncijumferita (SrFe12O19) inkorporirane su u etilcelulozu, sa ciljem pospešivanja difuzijekiseonika u odnosu na azot. Sinteza asimetričnih polimernih membrana na bazihidrogela ojačanog polietarsulfonom (PES) izvršena je kombinovanjem procesa fazneinverzije sa fotopolimerizacijom i umrežavanjem monomera Ispitivan je uticaj udelananočestica kod magnetnih nanokompozitnih i udela PES kod polimernih membrana namehanička i separaciona svojstva. Sa ciljem identifikacije struktura nastalihprocesiranjem membrana, izvršene su različite analize, kao što su skenirajućaelektronska mikroskopija (FESEM), mikroskopija atomskih sila (AFM), rendgentskodifrakcionaanaliza (XRD) i infracrvena spektroskopija sa Furijeovom transformacijom(FTIR) Mehanička svojstva membrana ispitivana su mikro Vikers metodom izatezanjem. Sorpciona kinetika ispitana je promenom koncentracije jona u rastvoru iopisana je korišćenjem različitih kinetičkih modela. Permeabilnost magnetnihnanokompozitnih membrana ispitana je praćenjem promene izlaznog pritiska smešeazota i kiseonika, kao i čistog azota. Membrane na bazi hidrogelova sa većim sadržajemPES pokazuju poboljšana mehanička svojstva, uz visok adsorpcioni kapacitet.Nanokompozitne magnetne membrane sa većim sadržajem magnetnih nanočesticapokazale su značajno poboljšanje mehaničkih svojstava u poređenju sa čistometilcelulozom, uz visoku permeabilnost. Navedene analize su pokazale da sunanokompozitne membrane na bazi etilceluloze odličan kandidat za separaciju gasova,dok membrane na bazi hidrogelova pokazuju visok potencijal za uklanjanje jona teškihmetala iz vode. Na osnovu dosadašnjih saznanja, navedeni materijali nisu bili predmetranijih istraživanja. The focus of this doctoral dissertation is on the preparation and characterization ofmagnetic nanocomposite membranes for gas separation, as well as on the preparationand characterization of polymer membranes for removal of heavy metal ions fromwater. In the processing of magnetic membranes, magnetic nanoparticles of bariumferrite (BaFe12O19) and strontium ferrite (SrFe12O19) were incorporated intoethylcellulose, in order to promote oxygen diffusion against nitrogen. Synthesis ofasymmetric hydrogel-based polymer membranes reinforced with polyethersulphone(PES) was performed by combining the phase inversion with photopolymerization andthe cross-linking of monomers. The influence of the nanoparticle content in magneticnanocomposite and the PES fraction in polymer membranes on the mechanical andseparation properties was investigated. In order to identify the structures formed bymembrane processing, various analyzes were performed, such as scanning electronmicroscopy (FESEM), atomic force microscopy (AFM), X-ray diffraction XRD andinfrared spectroscopy with Fourier transformation (FTIR). Mechanical properties of themembranes were investigated using micro Vickers method and tensile test. The sorptionkinetics has been followed with the measurements of ions concentration change in thesolution, and was described using different kinetic models. The permeability ofmagnetic nanocomposite membranes was tested by monitoring the output pressurechange of the nitrogen and oxygen mixtures, as well as pure nitrogen. Hydrogel-basedmembranes with a higher PES content showed enhanced mechanical properties, withhigh adsorption capacity. Nanocomposite magnetic membranes with a higher content ofmagnetic nanoparticles have shown a significant improvement in mechanical propertiescompared to pure ethylcellulose, with high permeability. These findings have shownthat nanocomposite membranes based on ethylcellulose are an excellent candidate forgas separation, while hydrogel-based membranes exhibit high potential for removal ofheavy metal ions from water. Based on our current knowledge, these materials have notbeen the subject of previous research.
- Published
- 2018
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