TY  - JOUR
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Fahrenholtz, William G.
AU  - Smith, Steven
AU  - Mirković, Miljana M.
AU  - Peleš Tadić, Adriana
AU  - Petrović, Jovana
AU  - Đorđević, Antonije
PY  - 2024
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12795
AB  - Magnesium titanate ceramics were prepared by reactive spark plasma sintering (SPS) at 1200 °C for 5 min. Prior to sintering, MgO and TiO2 powders were mixed by high energy ball milling (HEBM) for 15, 30, or 60 min. The effect of milling time on phase composition was analyzed by X-ray diffraction (XRD) for milled powders and sintered specimens. The morphology of the sintered ceramics was investigated by scanning electron microscopy (SEM), while elemental distribution was determined by energy dispersive spectroscopy (EDS). The presence of the MgTi2O5 phase was detected in XRD and was confirmed by EDS analysis. Microcracking was observed for specimens prepared with longer milling times and attributed to the coefficient of thermal expansion (CTE) mismatch dominantly due to the anisotropic crystal structure of MgTiO3 phase. The sample milled for 15 min showed the highest Vickers hardness due to less or no microcracking and nearly full density. The dielectric measurements in the range of 10 Hz–250 MHz demonstrated extremely high dielectric permittivity, as high as 104 at 1 kHz. An increase in loss tangents was observed due to oxygen vacancy formation, which was promoted by the vacuum environment during SPS. Oxygen vacancy-related dielectric relaxation was also detected and explained.
T2  - Ceramics International
T1  - Spark plasma sintering of magnesium titanate ceramics
IS  - InPress
DO  - 10.1016/j.ceramint.2024.02.004
ER  - 

@article{
author = "Filipović, Suzana and Obradović, Nina and Fahrenholtz, William G. and Smith, Steven and Mirković, Miljana M. and Peleš Tadić, Adriana and Petrović, Jovana and Đorđević, Antonije",
year = "2024",
abstract = "Magnesium titanate ceramics were prepared by reactive spark plasma sintering (SPS) at 1200 °C for 5 min. Prior to sintering, MgO and TiO2 powders were mixed by high energy ball milling (HEBM) for 15, 30, or 60 min. The effect of milling time on phase composition was analyzed by X-ray diffraction (XRD) for milled powders and sintered specimens. The morphology of the sintered ceramics was investigated by scanning electron microscopy (SEM), while elemental distribution was determined by energy dispersive spectroscopy (EDS). The presence of the MgTi2O5 phase was detected in XRD and was confirmed by EDS analysis. Microcracking was observed for specimens prepared with longer milling times and attributed to the coefficient of thermal expansion (CTE) mismatch dominantly due to the anisotropic crystal structure of MgTiO3 phase. The sample milled for 15 min showed the highest Vickers hardness due to less or no microcracking and nearly full density. The dielectric measurements in the range of 10 Hz–250 MHz demonstrated extremely high dielectric permittivity, as high as 104 at 1 kHz. An increase in loss tangents was observed due to oxygen vacancy formation, which was promoted by the vacuum environment during SPS. Oxygen vacancy-related dielectric relaxation was also detected and explained.",
journal = "Ceramics International",
title = "Spark plasma sintering of magnesium titanate ceramics",
number = "InPress",
doi = "10.1016/j.ceramint.2024.02.004"
}

Filipović, S., Obradović, N., Fahrenholtz, W. G., Smith, S., Mirković, M. M., Peleš Tadić, A., Petrović, J.,& Đorđević, A.. (2024). Spark plasma sintering of magnesium titanate ceramics. in Ceramics International(InPress).
https://doi.org/10.1016/j.ceramint.2024.02.004

Filipović S, Obradović N, Fahrenholtz WG, Smith S, Mirković MM, Peleš Tadić A, Petrović J, Đorđević A. Spark plasma sintering of magnesium titanate ceramics. in Ceramics International. 2024;(InPress).
doi:10.1016/j.ceramint.2024.02.004 .

Filipović, Suzana, Obradović, Nina, Fahrenholtz, William G., Smith, Steven, Mirković, Miljana M., Peleš Tadić, Adriana, Petrović, Jovana, Đorđević, Antonije, "Spark plasma sintering of magnesium titanate ceramics" in Ceramics International, no. InPress (2024),
https://doi.org/10.1016/j.ceramint.2024.02.004 . .

TY  - JOUR
AU  - Sknepnek, Aleksandra
AU  - Filipović, Suzana
AU  - Pavlović, Vladimir B.
AU  - Mirković, Nemanja
AU  - Miletić, Dunja
AU  - Gržetić, Jelena
AU  - Mirković, Miljana M.
PY  - 2024
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12793
AB  - Bacterial cellulose (BC) is a highly pure polysaccharide biopolymer that can be produced by various bacterial genera. Even though BC lacks functional properties, its porosity, three-dimensional network, and high specific surface area make it a suitable carrier for functional composite materials. In the present study, BC-producing bacteria were isolated from kombucha beverage and identified using a molecular method. Two sets of the BC hydrogels were produced in static conditions after four and seven days. Afterwards, two different synthesis pathways were applied for BC functionalization. The first method implied the incorporation of previously synthesized HAp/TiO2 nanocomposite using an immersion technique, while the second method included the functionalization of BC during the synthesis of HAp/TiO2 nanocomposite in the reaction mixture. The primary goal was to find the best method to obtain the functionalized material. Physicochemical and microstructural properties were analyzed by SEM, EDS, FTIR, and XRD methods. Further properties were examined by tensile test and thermogravimetric analysis, and antimicrobial activity was assessed by a total plate count assay. The results showed that HAp/TiO2 was successfully incorporated into the produced BC hydrogels using both methods. The applied methods of incorporation influenced the differences in morphology, phase distribution, mechanical and thermal properties, and antimicrobial activity against Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Proteus mirabilis (ATCC 12453), and Candida albicans (ATCC 10231). Composite material can be recommended for further development and application in environments that are suitable for diseases spreading.
T2  - Polymers
T1  - Effects of Synthesis Parameters on Structure and Antimicrobial Properties of Bacterial Cellulose/Hydroxyapatite/TiO2 Polymer–Ceramic Composite Material
VL  - 16
IS  - 4
SP  - 470
DO  - 10.3390/polym16040470
ER  - 

@article{
author = "Sknepnek, Aleksandra and Filipović, Suzana and Pavlović, Vladimir B. and Mirković, Nemanja and Miletić, Dunja and Gržetić, Jelena and Mirković, Miljana M.",
year = "2024",
abstract = "Bacterial cellulose (BC) is a highly pure polysaccharide biopolymer that can be produced by various bacterial genera. Even though BC lacks functional properties, its porosity, three-dimensional network, and high specific surface area make it a suitable carrier for functional composite materials. In the present study, BC-producing bacteria were isolated from kombucha beverage and identified using a molecular method. Two sets of the BC hydrogels were produced in static conditions after four and seven days. Afterwards, two different synthesis pathways were applied for BC functionalization. The first method implied the incorporation of previously synthesized HAp/TiO2 nanocomposite using an immersion technique, while the second method included the functionalization of BC during the synthesis of HAp/TiO2 nanocomposite in the reaction mixture. The primary goal was to find the best method to obtain the functionalized material. Physicochemical and microstructural properties were analyzed by SEM, EDS, FTIR, and XRD methods. Further properties were examined by tensile test and thermogravimetric analysis, and antimicrobial activity was assessed by a total plate count assay. The results showed that HAp/TiO2 was successfully incorporated into the produced BC hydrogels using both methods. The applied methods of incorporation influenced the differences in morphology, phase distribution, mechanical and thermal properties, and antimicrobial activity against Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Proteus mirabilis (ATCC 12453), and Candida albicans (ATCC 10231). Composite material can be recommended for further development and application in environments that are suitable for diseases spreading.",
journal = "Polymers",
title = "Effects of Synthesis Parameters on Structure and Antimicrobial Properties of Bacterial Cellulose/Hydroxyapatite/TiO2 Polymer–Ceramic Composite Material",
volume = "16",
number = "4",
pages = "470",
doi = "10.3390/polym16040470"
}

Sknepnek, A., Filipović, S., Pavlović, V. B., Mirković, N., Miletić, D., Gržetić, J.,& Mirković, M. M.. (2024). Effects of Synthesis Parameters on Structure and Antimicrobial Properties of Bacterial Cellulose/Hydroxyapatite/TiO2 Polymer–Ceramic Composite Material. in Polymers, 16(4), 470.
https://doi.org/10.3390/polym16040470

Sknepnek A, Filipović S, Pavlović VB, Mirković N, Miletić D, Gržetić J, Mirković MM. Effects of Synthesis Parameters on Structure and Antimicrobial Properties of Bacterial Cellulose/Hydroxyapatite/TiO2 Polymer–Ceramic Composite Material. in Polymers. 2024;16(4):470.
doi:10.3390/polym16040470 .

Sknepnek, Aleksandra, Filipović, Suzana, Pavlović, Vladimir B., Mirković, Nemanja, Miletić, Dunja, Gržetić, Jelena, Mirković, Miljana M., "Effects of Synthesis Parameters on Structure and Antimicrobial Properties of Bacterial Cellulose/Hydroxyapatite/TiO2 Polymer–Ceramic Composite Material" in Polymers, 16, no. 4 (2024):470,
https://doi.org/10.3390/polym16040470 . .