TY  - JOUR
AU  - Tadić, Marin
AU  - Trpkov, Đorđe
AU  - Kopanja, Lazar
AU  - Vojnović, Sandra
AU  - Panjan, Matjaž
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5892
AB  - In this work, we present the magnetic and structural properties of α-Fe 2 O 3 nanoparticles synthesized by the hydrothermal synthesis method. XRD, FTIR and Raman spectroscopy indicate that the samples consist of single-phase α-Fe 2 O 3 nanoparticles. A microstructural analysis by TEM and SEM shows: (i) irregular nanoparticles (∼50 nm), (ii) plate-like nanoparticles (with thickness t∼10 nm and diameter d∼50–80 nm) and (iii) microsized ellipsoid 3D superstructures (with length l∼3.5 and diameter d∼1.5 μm) composed of nanosized building blocks (∼50 nm). We used circularity, elongation and convexity measures to quantitatively analyze the shape of the particles. Irregular hematite nanoparticles were synthesized using a water solution of ferric precursor and sodium acetate during the hydrothermal reaction (reaction conditions: T = 180 °C, t = 12 h). The same hydrothermal reaction temperature, reaction duration and ferric precursor (without sodium acetate) were used for synthesizing hematite ellipsoid 3D superstructures. Addition of urea and glycine surfactants in hydrothermal reaction resulted in the formation of nanoplate hematite particles. The role of these surfactants on the structure and morphology of the particles was also investigated. Magnetic measurements at the room temperature displayed a wide range of coercivities, from H C = 73 Oe for irregular nanoparticles, H C = 689 Oe for nanoplates to H C = 2688 Oe for hematite ellipsoid 3D superstructures. The measured coercivity for the ellipsoid superstructure was about 35 times higher than in the case of irregular hematite nanoparticles and about 4 times than the coercivity of hematite nanoplates. Magnetic properties of synthesized samples were related to their structure and morphology. We conclude that shape anisotropy influenced enhancement of the coercivity in hematite nanoplates whereas hematite ellipsoid 3D superstructure (nanoparticle clusters) induced the formation of multidomain magnetic structure and highest coercivity revealing its superior structure for enhanced magnetic properties. The synthesized hematite nanoparticle structures exhibit low cytotoxicity levels on the human lung fibroblasts (MRC5) cell line demonstrating a safe use of these nanoparticles for practical applications. © 2019 Elsevier B.V.
T2  - Journal of Alloys and Compounds
T1  - Hydrothermal synthesis of hematite (α-Fe2O3) nanoparticle forms: Synthesis conditions, structure, particle shape analysis, cytotoxicity and magnetic properties
EP  - 609
SP  - 599
VL  - 792
DO  - 10.1016/j.jallcom.2019.03.414
ER  - 

@article{
author = "Tadić, Marin and Trpkov, Đorđe and Kopanja, Lazar and Vojnović, Sandra and Panjan, Matjaž",
year = "2019",
abstract = "In this work, we present the magnetic and structural properties of α-Fe 2 O 3 nanoparticles synthesized by the hydrothermal synthesis method. XRD, FTIR and Raman spectroscopy indicate that the samples consist of single-phase α-Fe 2 O 3 nanoparticles. A microstructural analysis by TEM and SEM shows: (i) irregular nanoparticles (∼50 nm), (ii) plate-like nanoparticles (with thickness t∼10 nm and diameter d∼50–80 nm) and (iii) microsized ellipsoid 3D superstructures (with length l∼3.5 and diameter d∼1.5 μm) composed of nanosized building blocks (∼50 nm). We used circularity, elongation and convexity measures to quantitatively analyze the shape of the particles. Irregular hematite nanoparticles were synthesized using a water solution of ferric precursor and sodium acetate during the hydrothermal reaction (reaction conditions: T = 180 °C, t = 12 h). The same hydrothermal reaction temperature, reaction duration and ferric precursor (without sodium acetate) were used for synthesizing hematite ellipsoid 3D superstructures. Addition of urea and glycine surfactants in hydrothermal reaction resulted in the formation of nanoplate hematite particles. The role of these surfactants on the structure and morphology of the particles was also investigated. Magnetic measurements at the room temperature displayed a wide range of coercivities, from H C = 73 Oe for irregular nanoparticles, H C = 689 Oe for nanoplates to H C = 2688 Oe for hematite ellipsoid 3D superstructures. The measured coercivity for the ellipsoid superstructure was about 35 times higher than in the case of irregular hematite nanoparticles and about 4 times than the coercivity of hematite nanoplates. Magnetic properties of synthesized samples were related to their structure and morphology. We conclude that shape anisotropy influenced enhancement of the coercivity in hematite nanoplates whereas hematite ellipsoid 3D superstructure (nanoparticle clusters) induced the formation of multidomain magnetic structure and highest coercivity revealing its superior structure for enhanced magnetic properties. The synthesized hematite nanoparticle structures exhibit low cytotoxicity levels on the human lung fibroblasts (MRC5) cell line demonstrating a safe use of these nanoparticles for practical applications. © 2019 Elsevier B.V.",
journal = "Journal of Alloys and Compounds",
title = "Hydrothermal synthesis of hematite (α-Fe2O3) nanoparticle forms: Synthesis conditions, structure, particle shape analysis, cytotoxicity and magnetic properties",
pages = "609-599",
volume = "792",
doi = "10.1016/j.jallcom.2019.03.414"
}

Tadić, M., Trpkov, Đ., Kopanja, L., Vojnović, S.,& Panjan, M.. (2019). Hydrothermal synthesis of hematite (α-Fe2O3) nanoparticle forms: Synthesis conditions, structure, particle shape analysis, cytotoxicity and magnetic properties. in Journal of Alloys and Compounds, 792, 599-609.
https://doi.org/10.1016/j.jallcom.2019.03.414

Tadić M, Trpkov Đ, Kopanja L, Vojnović S, Panjan M. Hydrothermal synthesis of hematite (α-Fe2O3) nanoparticle forms: Synthesis conditions, structure, particle shape analysis, cytotoxicity and magnetic properties. in Journal of Alloys and Compounds. 2019;792:599-609.
doi:10.1016/j.jallcom.2019.03.414 .

Tadić, Marin, Trpkov, Đorđe, Kopanja, Lazar, Vojnović, Sandra, Panjan, Matjaž, "Hydrothermal synthesis of hematite (α-Fe2O3) nanoparticle forms: Synthesis conditions, structure, particle shape analysis, cytotoxicity and magnetic properties" in Journal of Alloys and Compounds, 792 (2019):599-609,
https://doi.org/10.1016/j.jallcom.2019.03.414 . .

TY  - JOUR
AU  - Trpkov, Đorđe
AU  - Panjan, Matjaž
AU  - Kopanja, Lazar
AU  - Tadić, Marin
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5874
AB  - We report on glycine-free and glycine-assisted hydrothermal synthesis of microsized superstructures composed of self-assembled hematite nanoparticles. An X-ray powder diffraction measurements of the samples confirm good crystallization of the hematite nanoparticles with hydrothermal reaction time-dependent crystallite sizes in a range from ∼15 nm (45 h) to ∼26 nm (90 h). The FTIR and Raman spectroscopy confirm hematite structure, whereas TEM measurements reveal nanoparticle sub-units (subparticles). The computational analyses of particle shape show that the addition of glycine surfactant in hydrothermal reaction leads to more spherical shape of hematite hierarchical structures and smaller sizes. We found strong coercivity increases (up to ∼3 times) in the samples synthesized in the presence of glycine. The coercivity values from HC = 1305 Oe (mushroom-like shape synthesized by glycine-free hydrothermal reaction) to HC = 3725 Oe (sphere-like shape synthesized by glycine-assisted hydrothermal reaction) were obtained at 300 K. These results and their comparison with other described in the literature (e.g. bulk, wires, urchin-like, rods, tubes, plates, star-like, dendrites, platelets, irregular, nanocolumns, spindles, disks hematites, etc.) reveal that the hematite superstructures possess good magnetic properties. We propose that the glycine, oriented subparticles, exchange and dipole-dipole interactions may play an important role in the development of magnetic properties.
T2  - Applied Surface Science
T1  - Hydrothermal synthesis, morphology, magnetic properties and self-assembly of hierarchical α-Fe2O3 (hematite) mushroom-, cube- and sphere-like superstructures
EP  - 438
SP  - 427
VL  - 457
DO  - 10.1016/j.apsusc.2018.06.224
ER  - 

@article{
author = "Trpkov, Đorđe and Panjan, Matjaž and Kopanja, Lazar and Tadić, Marin",
year = "2018",
abstract = "We report on glycine-free and glycine-assisted hydrothermal synthesis of microsized superstructures composed of self-assembled hematite nanoparticles. An X-ray powder diffraction measurements of the samples confirm good crystallization of the hematite nanoparticles with hydrothermal reaction time-dependent crystallite sizes in a range from ∼15 nm (45 h) to ∼26 nm (90 h). The FTIR and Raman spectroscopy confirm hematite structure, whereas TEM measurements reveal nanoparticle sub-units (subparticles). The computational analyses of particle shape show that the addition of glycine surfactant in hydrothermal reaction leads to more spherical shape of hematite hierarchical structures and smaller sizes. We found strong coercivity increases (up to ∼3 times) in the samples synthesized in the presence of glycine. The coercivity values from HC = 1305 Oe (mushroom-like shape synthesized by glycine-free hydrothermal reaction) to HC = 3725 Oe (sphere-like shape synthesized by glycine-assisted hydrothermal reaction) were obtained at 300 K. These results and their comparison with other described in the literature (e.g. bulk, wires, urchin-like, rods, tubes, plates, star-like, dendrites, platelets, irregular, nanocolumns, spindles, disks hematites, etc.) reveal that the hematite superstructures possess good magnetic properties. We propose that the glycine, oriented subparticles, exchange and dipole-dipole interactions may play an important role in the development of magnetic properties.",
journal = "Applied Surface Science",
title = "Hydrothermal synthesis, morphology, magnetic properties and self-assembly of hierarchical α-Fe2O3 (hematite) mushroom-, cube- and sphere-like superstructures",
pages = "438-427",
volume = "457",
doi = "10.1016/j.apsusc.2018.06.224"
}

Trpkov, Đ., Panjan, M., Kopanja, L.,& Tadić, M.. (2018). Hydrothermal synthesis, morphology, magnetic properties and self-assembly of hierarchical α-Fe2O3 (hematite) mushroom-, cube- and sphere-like superstructures. in Applied Surface Science, 457, 427-438.
https://doi.org/10.1016/j.apsusc.2018.06.224

Trpkov Đ, Panjan M, Kopanja L, Tadić M. Hydrothermal synthesis, morphology, magnetic properties and self-assembly of hierarchical α-Fe2O3 (hematite) mushroom-, cube- and sphere-like superstructures. in Applied Surface Science. 2018;457:427-438.
doi:10.1016/j.apsusc.2018.06.224 .

Trpkov, Đorđe, Panjan, Matjaž, Kopanja, Lazar, Tadić, Marin, "Hydrothermal synthesis, morphology, magnetic properties and self-assembly of hierarchical α-Fe2O3 (hematite) mushroom-, cube- and sphere-like superstructures" in Applied Surface Science, 457 (2018):427-438,
https://doi.org/10.1016/j.apsusc.2018.06.224 . .

TY  - JOUR
AU  - Demajo, Miroslav A.
AU  - Cvetićanin, Jelena M.
AU  - Stoiljković, Milovan
AU  - Trpkov, Đorđe
AU  - Andrić, Velibor
AU  - Onjia, Antonije
AU  - Nešković, Olivera M.
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1903
AB  - In this study, we analysed pellets from long-eared owls (Asio otus) collected from four localities in Belgrade (Serbia). The pellets contained the remains of prey, namely voles (Arvicola terrestris) and field mice (Apodemus agrarius). The concentrations of 14 elements (Ca, P, Mg, Na, K, Fe, Zn, Sr, Ba, Mn, Ti, Cu, Si, B) were evaluated in whole pellets and in samples containing only bone tissue, which were dissected from the whole pellet. The increased levels of certain elements, including Mn, Zn, Ba, Cu and radioactive K-40, indicate contamination of the soil by various sources, such as industrial plants and agricultural practices. From the results presented in this article, we suggest that the analysis of owl pellets may indicate the quality of the local environment.
PB  - Taylor & Francis Ltd, Abingdon
T2  - Chemistry and Ecology
T1  - Detection of elements and radioactivity in pellets from long-eared owls (Asio otus) inhabiting the city of Belgrade (Serbia)
EP  - 400
IS  - 5
SP  - 393
VL  - 27
DO  - 10.1080/02757540.2011.607440
ER  - 

@article{
author = "Demajo, Miroslav A. and Cvetićanin, Jelena M. and Stoiljković, Milovan and Trpkov, Đorđe and Andrić, Velibor and Onjia, Antonije and Nešković, Olivera M.",
year = "2011",
abstract = "In this study, we analysed pellets from long-eared owls (Asio otus) collected from four localities in Belgrade (Serbia). The pellets contained the remains of prey, namely voles (Arvicola terrestris) and field mice (Apodemus agrarius). The concentrations of 14 elements (Ca, P, Mg, Na, K, Fe, Zn, Sr, Ba, Mn, Ti, Cu, Si, B) were evaluated in whole pellets and in samples containing only bone tissue, which were dissected from the whole pellet. The increased levels of certain elements, including Mn, Zn, Ba, Cu and radioactive K-40, indicate contamination of the soil by various sources, such as industrial plants and agricultural practices. From the results presented in this article, we suggest that the analysis of owl pellets may indicate the quality of the local environment.",
publisher = "Taylor & Francis Ltd, Abingdon",
journal = "Chemistry and Ecology",
title = "Detection of elements and radioactivity in pellets from long-eared owls (Asio otus) inhabiting the city of Belgrade (Serbia)",
pages = "400-393",
number = "5",
volume = "27",
doi = "10.1080/02757540.2011.607440"
}

Demajo, M. A., Cvetićanin, J. M., Stoiljković, M., Trpkov, Đ., Andrić, V., Onjia, A.,& Nešković, O. M.. (2011). Detection of elements and radioactivity in pellets from long-eared owls (Asio otus) inhabiting the city of Belgrade (Serbia). in Chemistry and Ecology
Taylor & Francis Ltd, Abingdon., 27(5), 393-400.
https://doi.org/10.1080/02757540.2011.607440

Demajo MA, Cvetićanin JM, Stoiljković M, Trpkov Đ, Andrić V, Onjia A, Nešković OM. Detection of elements and radioactivity in pellets from long-eared owls (Asio otus) inhabiting the city of Belgrade (Serbia). in Chemistry and Ecology. 2011;27(5):393-400.
doi:10.1080/02757540.2011.607440 .

Demajo, Miroslav A., Cvetićanin, Jelena M., Stoiljković, Milovan, Trpkov, Đorđe, Andrić, Velibor, Onjia, Antonije, Nešković, Olivera M., "Detection of elements and radioactivity in pellets from long-eared owls (Asio otus) inhabiting the city of Belgrade (Serbia)" in Chemistry and Ecology, 27, no. 5 (2011):393-400,
https://doi.org/10.1080/02757540.2011.607440 . .