TY  - JOUR
AU  - Jelić, Aleksandra
AU  - Sekulić, Milica
AU  - Travica, Milan
AU  - Gržetić, Jelena
AU  - Ugrinović, Vukašin
AU  - Marinković, Aleksandar D.
AU  - Božić, Aleksandra
AU  - Stamenović, Marina
AU  - Putić, Slaviša
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5110
AB  - In this study, silicate nanofillers; dicalcium silicate, magnesium silicate, tricalcium silicate, and wollastonite; were synthesized using four different methods and incorporated into the epoxy resin to improve its mechanical properties. Characterization of the newly synthesized nanofillers was performed using Fourier-transformation infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The purpose of this study was to analyze newly developed composite materials reinforced with silicate nanoparticles utilizing tensile testing and a full-field non-contact 3D Digital Image Correlation (DIC) method. Analysis of deformation and displacement fields gives precise material behavior during testing. Testing results allowed a more reliable assessment of the structural integrity of epoxy composite materials reinforced using different silicate nanofillers. It was concluded that the addition of 3% of dicalcium silicate, magnesium silicate, tricalcium silicate, and wollastonite lead to the increasement of tensile strength up to 31.5%, 29.0%, 27.5%, and 23.5% in comparison with neat epoxy, respectively. In order to offer more trustworthy information about the viscoelastic behavior of neat epoxy and composites, a dynamic mechanical analysis (DMA) was also performed and rheological measurements of uncured epoxy matrix and epoxy suspensions were obtained.
PB  - MDPI
T2  - Polymers
T1  - Determination of Mechanical Properties of Epoxy Composite Materials Reinforced with Silicate Nanofillers Using Digital Image Correlation (DIC)
IS  - 6
SP  - 1255
VL  - 14
DO  - 10.3390/polym14061255
ER  - 

@article{
author = "Jelić, Aleksandra and Sekulić, Milica and Travica, Milan and Gržetić, Jelena and Ugrinović, Vukašin and Marinković, Aleksandar D. and Božić, Aleksandra and Stamenović, Marina and Putić, Slaviša",
year = "2022",
abstract = "In this study, silicate nanofillers; dicalcium silicate, magnesium silicate, tricalcium silicate, and wollastonite; were synthesized using four different methods and incorporated into the epoxy resin to improve its mechanical properties. Characterization of the newly synthesized nanofillers was performed using Fourier-transformation infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The purpose of this study was to analyze newly developed composite materials reinforced with silicate nanoparticles utilizing tensile testing and a full-field non-contact 3D Digital Image Correlation (DIC) method. Analysis of deformation and displacement fields gives precise material behavior during testing. Testing results allowed a more reliable assessment of the structural integrity of epoxy composite materials reinforced using different silicate nanofillers. It was concluded that the addition of 3% of dicalcium silicate, magnesium silicate, tricalcium silicate, and wollastonite lead to the increasement of tensile strength up to 31.5%, 29.0%, 27.5%, and 23.5% in comparison with neat epoxy, respectively. In order to offer more trustworthy information about the viscoelastic behavior of neat epoxy and composites, a dynamic mechanical analysis (DMA) was also performed and rheological measurements of uncured epoxy matrix and epoxy suspensions were obtained.",
publisher = "MDPI",
journal = "Polymers",
title = "Determination of Mechanical Properties of Epoxy Composite Materials Reinforced with Silicate Nanofillers Using Digital Image Correlation (DIC)",
number = "6",
pages = "1255",
volume = "14",
doi = "10.3390/polym14061255"
}

Jelić, A., Sekulić, M., Travica, M., Gržetić, J., Ugrinović, V., Marinković, A. D., Božić, A., Stamenović, M.,& Putić, S.. (2022). Determination of Mechanical Properties of Epoxy Composite Materials Reinforced with Silicate Nanofillers Using Digital Image Correlation (DIC). in Polymers
MDPI., 14(6), 1255.
https://doi.org/10.3390/polym14061255

Jelić A, Sekulić M, Travica M, Gržetić J, Ugrinović V, Marinković AD, Božić A, Stamenović M, Putić S. Determination of Mechanical Properties of Epoxy Composite Materials Reinforced with Silicate Nanofillers Using Digital Image Correlation (DIC). in Polymers. 2022;14(6):1255.
doi:10.3390/polym14061255 .

Jelić, Aleksandra, Sekulić, Milica, Travica, Milan, Gržetić, Jelena, Ugrinović, Vukašin, Marinković, Aleksandar D., Božić, Aleksandra, Stamenović, Marina, Putić, Slaviša, "Determination of Mechanical Properties of Epoxy Composite Materials Reinforced with Silicate Nanofillers Using Digital Image Correlation (DIC)" in Polymers, 14, no. 6 (2022):1255,
https://doi.org/10.3390/polym14061255 . .

TY  - JOUR
AU  - Jelić, Aleksandra
AU  - Božić, A.
AU  - Stamenović, Marina
AU  - Sekulić, Milica
AU  - Porobić, Slavica
AU  - Dikić, Stefan
AU  - Putić, Slaviša
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4587
AB  - Halloysite nanotubes (HNTs), naturally occurring as aluminosilicate nanoclay mineral, have recently emerged as a possible nanomaterial for countless applications due to their specific chemical structure, tubular shape, high aspect ratio, biocompatibility and low toxicity. In this study, HNTs were incorporated into the epoxy resin matrix to improve its mechanical properties and thermal stability. However, heterogeneous size, surface charge and surface hydrogen bond formation, result in aggregation of HNTs in epoxies to a certain extent. Three specific techniques were used to integrate HNTs into neat epoxy resin (NE). The structure and morphology of the embedded nanotubes were confirmed by Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Tensile testing was carried out and the fractured surface of the tested specimen was analysed using scanning electron microscopy (SEM). The thermal stability of the prepared nanocomposite materials was investigated by thermogravimetric (TG) and derivative thermogravimetry (DTG) studies. The obtained results indicated that improved properties of HNTs/epoxy nanocomposite materials were related to the unique properties of well-dispersed HNTs, agglomerate scale, and reduced void presence, and could be controlled by the manufacturing processes.
PB  - International Conference on New Technologies, Development and Application, NT 2020
T2  - Lecture Notes in Networks and Systems
T1  - Effects of dispersion and particle-matrix interactions on mechanical and thermal properties of hnt/epoxy nanocomposite materials
EP  - 325
SP  - 310
VL  - 153
DO  - 10.1007/978-3-030-58362-0_18
ER  - 

@article{
author = "Jelić, Aleksandra and Božić, A. and Stamenović, Marina and Sekulić, Milica and Porobić, Slavica and Dikić, Stefan and Putić, Slaviša",
year = "2021",
abstract = "Halloysite nanotubes (HNTs), naturally occurring as aluminosilicate nanoclay mineral, have recently emerged as a possible nanomaterial for countless applications due to their specific chemical structure, tubular shape, high aspect ratio, biocompatibility and low toxicity. In this study, HNTs were incorporated into the epoxy resin matrix to improve its mechanical properties and thermal stability. However, heterogeneous size, surface charge and surface hydrogen bond formation, result in aggregation of HNTs in epoxies to a certain extent. Three specific techniques were used to integrate HNTs into neat epoxy resin (NE). The structure and morphology of the embedded nanotubes were confirmed by Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Tensile testing was carried out and the fractured surface of the tested specimen was analysed using scanning electron microscopy (SEM). The thermal stability of the prepared nanocomposite materials was investigated by thermogravimetric (TG) and derivative thermogravimetry (DTG) studies. The obtained results indicated that improved properties of HNTs/epoxy nanocomposite materials were related to the unique properties of well-dispersed HNTs, agglomerate scale, and reduced void presence, and could be controlled by the manufacturing processes.",
publisher = "International Conference on New Technologies, Development and Application, NT 2020",
journal = "Lecture Notes in Networks and Systems",
title = "Effects of dispersion and particle-matrix interactions on mechanical and thermal properties of hnt/epoxy nanocomposite materials",
pages = "325-310",
volume = "153",
doi = "10.1007/978-3-030-58362-0_18"
}

Jelić, A., Božić, A., Stamenović, M., Sekulić, M., Porobić, S., Dikić, S.,& Putić, S.. (2021). Effects of dispersion and particle-matrix interactions on mechanical and thermal properties of hnt/epoxy nanocomposite materials. in Lecture Notes in Networks and Systems
International Conference on New Technologies, Development and Application, NT 2020., 153, 310-325.
https://doi.org/10.1007/978-3-030-58362-0_18

Jelić A, Božić A, Stamenović M, Sekulić M, Porobić S, Dikić S, Putić S. Effects of dispersion and particle-matrix interactions on mechanical and thermal properties of hnt/epoxy nanocomposite materials. in Lecture Notes in Networks and Systems. 2021;153:310-325.
doi:10.1007/978-3-030-58362-0_18 .

Jelić, Aleksandra, Božić, A., Stamenović, Marina, Sekulić, Milica, Porobić, Slavica, Dikić, Stefan, Putić, Slaviša, "Effects of dispersion and particle-matrix interactions on mechanical and thermal properties of hnt/epoxy nanocomposite materials" in Lecture Notes in Networks and Systems, 153 (2021):310-325,
https://doi.org/10.1007/978-3-030-58362-0_18 . .

TY  - JOUR
AU  - Jelić, Aleksandra
AU  - Sekulić, Milica
AU  - Stamenović, Marina
AU  - Ugrinović, Vukašin
AU  - Putić, Slaviša
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4399
AB  - The paper presents static and dynamic tests of carbon/epoxy composite materials with fiber orientation at 0 degrees/90 degrees and +/- 45 degrees. 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/m(3). 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.
PB  - Savez hemijskih inženjera, Beograd
T2  - Hemijska industrija
T1  - Micromechanical analysis of fatigue and crack growth in carbon-fiber epoxy composites based on mechanical testing
EP  - 264
IS  - 4
SP  - 257
VL  - 74
DO  - 10.2298/HEMIND200615022J
ER  - 

@article{
author = "Jelić, Aleksandra and Sekulić, Milica and Stamenović, Marina and Ugrinović, Vukašin and Putić, Slaviša",
year = "2020",
abstract = "The paper presents static and dynamic tests of carbon/epoxy composite materials with fiber orientation at 0 degrees/90 degrees and +/- 45 degrees. 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/m(3). 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.",
publisher = "Savez hemijskih inženjera, Beograd",
journal = "Hemijska industrija",
title = "Micromechanical analysis of fatigue and crack growth in carbon-fiber epoxy composites based on mechanical testing",
pages = "264-257",
number = "4",
volume = "74",
doi = "10.2298/HEMIND200615022J"
}

Jelić, A., Sekulić, M., Stamenović, M., Ugrinović, V.,& Putić, S.. (2020). Micromechanical analysis of fatigue and crack growth in carbon-fiber epoxy composites based on mechanical testing. in Hemijska industrija
Savez hemijskih inženjera, Beograd., 74(4), 257-264.
https://doi.org/10.2298/HEMIND200615022J

Jelić A, Sekulić M, Stamenović M, Ugrinović V, Putić S. Micromechanical analysis of fatigue and crack growth in carbon-fiber epoxy composites based on mechanical testing. in Hemijska industrija. 2020;74(4):257-264.
doi:10.2298/HEMIND200615022J .

Jelić, Aleksandra, Sekulić, Milica, Stamenović, Marina, Ugrinović, Vukašin, Putić, Slaviša, "Micromechanical analysis of fatigue and crack growth in carbon-fiber epoxy composites based on mechanical testing" in Hemijska industrija, 74, no. 4 (2020):257-264,
https://doi.org/10.2298/HEMIND200615022J . .

TY  - JOUR
AU  - Davidović, Slađana
AU  - Lazić, Vesna M.
AU  - Miljković, Miona
AU  - Gordić, Milan V.
AU  - Sekulić, Milica
AU  - Marinović-Cincović, Milena
AU  - Ratnayake, Ishara S.
AU  - Ahrenkiel, Scott Phillip
AU  - Nedeljković, Jovan
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4081
AB  - The antibacterial ability of in situ prepared nanometer-sized silver particles, immobilized in agar-agar films, was studied as a function of the concentration of co-dopant, magnesium ions. Content of inorganic components in hybrid films was determined using inductively coupled plasma optic emission spectroscopy, and found to be low (  lt  2 wt.-%). Morphology of prepared hybrid films, studied by transmission electron microscopy, revealed the presence of non-agglomerated and randomly distributed 10-20 nm silver nanoparticles (Ag NPs) within the agar-agar matrices. Fourier-transform infrared spectroscopy indicated the distinct chemical interaction between Ag NPs and polymer chains. Thermogravimetric analysis, as well as the determination of tensile strength, Young's modulus, and elongation at break showed improvement of thermal stability and mechanical properties of agar-agar matrices upon the incorporation of Ag NPs due to high compatibility between the hydrophilic organic component and inorganic components. The complete microbial reduction of Gram-positive bacteria Staphylococcus aureus was observed for all agar-silver films, while satisfactory results were observed for Gram-negative bacteria Pseudomonas aeruginosa (  gt = 99.6%). The release of Ag+ ions is suppressed by the increase of the concentration of Mg2+ ions and it was found to be significantly smaller (  lt = 0.24 ppm) than the harmful ecological level (1 ppm).
PB  - Elsevier Sci Ltd, Oxford
T2  - Carbohydrate Polymers
T1  - Antibacterial ability of immobilized silver nanoparticles in agar-agar films co-doped with magnesium ions
VL  - 224
DO  - 10.1016/j.carbpol.2019.115187
ER  - 

@article{
author = "Davidović, Slađana and Lazić, Vesna M. and Miljković, Miona and Gordić, Milan V. and Sekulić, Milica and Marinović-Cincović, Milena and Ratnayake, Ishara S. and Ahrenkiel, Scott Phillip and Nedeljković, Jovan",
year = "2019",
abstract = "The antibacterial ability of in situ prepared nanometer-sized silver particles, immobilized in agar-agar films, was studied as a function of the concentration of co-dopant, magnesium ions. Content of inorganic components in hybrid films was determined using inductively coupled plasma optic emission spectroscopy, and found to be low (  lt  2 wt.-%). Morphology of prepared hybrid films, studied by transmission electron microscopy, revealed the presence of non-agglomerated and randomly distributed 10-20 nm silver nanoparticles (Ag NPs) within the agar-agar matrices. Fourier-transform infrared spectroscopy indicated the distinct chemical interaction between Ag NPs and polymer chains. Thermogravimetric analysis, as well as the determination of tensile strength, Young's modulus, and elongation at break showed improvement of thermal stability and mechanical properties of agar-agar matrices upon the incorporation of Ag NPs due to high compatibility between the hydrophilic organic component and inorganic components. The complete microbial reduction of Gram-positive bacteria Staphylococcus aureus was observed for all agar-silver films, while satisfactory results were observed for Gram-negative bacteria Pseudomonas aeruginosa (  gt = 99.6%). The release of Ag+ ions is suppressed by the increase of the concentration of Mg2+ ions and it was found to be significantly smaller (  lt = 0.24 ppm) than the harmful ecological level (1 ppm).",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Carbohydrate Polymers",
title = "Antibacterial ability of immobilized silver nanoparticles in agar-agar films co-doped with magnesium ions",
volume = "224",
doi = "10.1016/j.carbpol.2019.115187"
}

Davidović, S., Lazić, V. M., Miljković, M., Gordić, M. V., Sekulić, M., Marinović-Cincović, M., Ratnayake, I. S., Ahrenkiel, S. P.,& Nedeljković, J.. (2019). Antibacterial ability of immobilized silver nanoparticles in agar-agar films co-doped with magnesium ions. in Carbohydrate Polymers
Elsevier Sci Ltd, Oxford., 224.
https://doi.org/10.1016/j.carbpol.2019.115187

Davidović S, Lazić VM, Miljković M, Gordić MV, Sekulić M, Marinović-Cincović M, Ratnayake IS, Ahrenkiel SP, Nedeljković J. Antibacterial ability of immobilized silver nanoparticles in agar-agar films co-doped with magnesium ions. in Carbohydrate Polymers. 2019;224.
doi:10.1016/j.carbpol.2019.115187 .

Davidović, Slađana, Lazić, Vesna M., Miljković, Miona, Gordić, Milan V., Sekulić, Milica, Marinović-Cincović, Milena, Ratnayake, Ishara S., Ahrenkiel, Scott Phillip, Nedeljković, Jovan, "Antibacterial ability of immobilized silver nanoparticles in agar-agar films co-doped with magnesium ions" in Carbohydrate Polymers, 224 (2019),
https://doi.org/10.1016/j.carbpol.2019.115187 . .

TY  - JOUR
AU  - Vujčić, Ivica
AU  - Gavrilović, Tamara V.
AU  - Sekulić, Milica
AU  - Mašić, Slobodan
AU  - Putić, Slaviša
AU  - Papan, Jelena
AU  - Dramićanin, Miroslav
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4039
AB  - Eu3+ activated LaPO4 phosphors were prepared by a high-temperature solid-state method and irradiated to different high-doses gamma-radiation in the 0-4 MGy range. No effects of high-doses of high-energy radiation on phosphor's morphology and structure were observed, as documented by electron microscopy and X-ray diffraction measurements. On the other hand, photoluminescence measurements showed that emission properties of phosphor were affected by gamma-radiation; changes in radiative properties being prominent for absorbed radiation doses up to 250 kGy after which no additional changes are observed. Judd-Ofelt analysis of emission spectra is performed to thoroughly investigate radiative properties of phosphors. Analysis showed that radiative transition probability of Eu3+ emission decreases while non-radiative probability increases upon gamma-irradiation. Quantum efficiency of emission is decreased from about 46% to 35% when Eu3+ doped LaPO4 powders are exposed to gamma-radiation of 250 kGy dose, showing no additional decrease for higher gamma-radiation doses.
PB  - Elsevier Science Bv, Amsterdam
T2  - Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Ato
T1  - Gamma-radiation effects on luminescence properties of Eu3+ activated LaPO4 phosphor
EP  - 90
SP  - 85
VL  - 422
DO  - 10.1016/j.nimb.2018.03.002
ER  - 

@article{
author = "Vujčić, Ivica and Gavrilović, Tamara V. and Sekulić, Milica and Mašić, Slobodan and Putić, Slaviša and Papan, Jelena and Dramićanin, Miroslav",
year = "2018",
abstract = "Eu3+ activated LaPO4 phosphors were prepared by a high-temperature solid-state method and irradiated to different high-doses gamma-radiation in the 0-4 MGy range. No effects of high-doses of high-energy radiation on phosphor's morphology and structure were observed, as documented by electron microscopy and X-ray diffraction measurements. On the other hand, photoluminescence measurements showed that emission properties of phosphor were affected by gamma-radiation; changes in radiative properties being prominent for absorbed radiation doses up to 250 kGy after which no additional changes are observed. Judd-Ofelt analysis of emission spectra is performed to thoroughly investigate radiative properties of phosphors. Analysis showed that radiative transition probability of Eu3+ emission decreases while non-radiative probability increases upon gamma-irradiation. Quantum efficiency of emission is decreased from about 46% to 35% when Eu3+ doped LaPO4 powders are exposed to gamma-radiation of 250 kGy dose, showing no additional decrease for higher gamma-radiation doses.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Ato",
title = "Gamma-radiation effects on luminescence properties of Eu3+ activated LaPO4 phosphor",
pages = "90-85",
volume = "422",
doi = "10.1016/j.nimb.2018.03.002"
}

Vujčić, I., Gavrilović, T. V., Sekulić, M., Mašić, S., Putić, S., Papan, J.,& Dramićanin, M.. (2018). Gamma-radiation effects on luminescence properties of Eu3+ activated LaPO4 phosphor. in Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Ato
Elsevier Science Bv, Amsterdam., 422, 85-90.
https://doi.org/10.1016/j.nimb.2018.03.002

Vujčić I, Gavrilović TV, Sekulić M, Mašić S, Putić S, Papan J, Dramićanin M. Gamma-radiation effects on luminescence properties of Eu3+ activated LaPO4 phosphor. in Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Ato. 2018;422:85-90.
doi:10.1016/j.nimb.2018.03.002 .

Vujčić, Ivica, Gavrilović, Tamara V., Sekulić, Milica, Mašić, Slobodan, Putić, Slaviša, Papan, Jelena, Dramićanin, Miroslav, "Gamma-radiation effects on luminescence properties of Eu3+ activated LaPO4 phosphor" in Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Ato, 422 (2018):85-90,
https://doi.org/10.1016/j.nimb.2018.03.002 . .