TY  - JOUR
AU  - Nikolić, V.
AU  - Lončarević, Branka
AU  - Popović, Aleksandar R.
PY  - 2018
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2411
AB  - Biodegradation of methacrylic acid and starch graft copolymers was investigated for the first time in this manuscript. Synthesized copolymer was characterized by 1H nuclear magnetic resonance spectroscopy (NMR), Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and elemental analysis. Copolymers with different percentage of grafting, G (%), were buried in three different types of soil. Biodegradation was monitored by measuring mass loss of the samples and using FTIR and SEM. The highest weight loss was in soil for the orchid growth (all samples had biodegradation higher than 89%), followed by soil for the cactus growth (mass loss higher than 70%) and soil rich in humus where some of the samples had biodegradation rate near or less than 50%. The correlation between G (%) and percent of weight loss after biodegradation was not significant in any types of soil. FTIR and SEM showed that after biodegradation, samples still contained both building components. Respiration test showed higher O2 consumption and CO2 production comparing to polystyrene which confirmed biodegradability of the accessible starch in copolymer. Based on the obtained results, degradation mechanism is proposed. First step is biodegradation of easily accessible starch followed by dissolution of the poly(methacrylic acid). This mechanism confirmed that biodegradation depends not only on the percentage of grafting, but also on molecular packaging, chains arrangement and the number and types of microorganisms present in the specific types of soils.
PB  - Springer Verlag
T2  - Polymer Bulletin
T1  - Biodegradation of copolymer obtained by grafting reaction between methacrylic acid and starch
VL  - 76
SP  - 2197
EP  - 2213
DO  - 10.1007/s00289-018-2484-x
ER  - 

@article{
author = "Nikolić, V. and Lončarević, Branka and Popović, Aleksandar R.",
year = "2018",
abstract = "Biodegradation of methacrylic acid and starch graft copolymers was investigated for the first time in this manuscript. Synthesized copolymer was characterized by 1H nuclear magnetic resonance spectroscopy (NMR), Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and elemental analysis. Copolymers with different percentage of grafting, G (%), were buried in three different types of soil. Biodegradation was monitored by measuring mass loss of the samples and using FTIR and SEM. The highest weight loss was in soil for the orchid growth (all samples had biodegradation higher than 89%), followed by soil for the cactus growth (mass loss higher than 70%) and soil rich in humus where some of the samples had biodegradation rate near or less than 50%. The correlation between G (%) and percent of weight loss after biodegradation was not significant in any types of soil. FTIR and SEM showed that after biodegradation, samples still contained both building components. Respiration test showed higher O2 consumption and CO2 production comparing to polystyrene which confirmed biodegradability of the accessible starch in copolymer. Based on the obtained results, degradation mechanism is proposed. First step is biodegradation of easily accessible starch followed by dissolution of the poly(methacrylic acid). This mechanism confirmed that biodegradation depends not only on the percentage of grafting, but also on molecular packaging, chains arrangement and the number and types of microorganisms present in the specific types of soils.",
publisher = "Springer Verlag",
journal = "Polymer Bulletin",
title = "Biodegradation of copolymer obtained by grafting reaction between methacrylic acid and starch",
volume = "76",
pages = "2197-2213",
doi = "10.1007/s00289-018-2484-x"
}

Nikolić, V., Lončarević, B.,& Popović, A. R.. (2018). Biodegradation of copolymer obtained by grafting reaction between methacrylic acid and starch. in Polymer Bulletin
Springer Verlag., 76, 2197-2213.
https://doi.org/10.1007/s00289-018-2484-x

Nikolić V, Lončarević B, Popović AR. Biodegradation of copolymer obtained by grafting reaction between methacrylic acid and starch. in Polymer Bulletin. 2018;76:2197-2213.
doi:10.1007/s00289-018-2484-x .

Nikolić, V., Lončarević, Branka, Popović, Aleksandar R., "Biodegradation of copolymer obtained by grafting reaction between methacrylic acid and starch" in Polymer Bulletin, 76 (2018):2197-2213,
https://doi.org/10.1007/s00289-018-2484-x . .

TY  - JOUR
AU  - Stoiljković, Zora
AU  - Jovanović, Vladislava M.
AU  - Mijin, Dušan
AU  - Nikolić, V.
AU  - Nikolic, Lj.
AU  - Petrović, Slobodan D.
AU  - Avramov Ivić, Milka
PY  - 2013
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1221
AB  - The electrochemical behavior of inclusion complexes of nifedipine (Nif) and amlodipine (Aml), a long-acting calcium channel blockers dihydropyridine (DHP) class, with beta-cyclodextrin (beta CD) and (2-hydroxypropyl)-beta-cyclodextrin (HP beta CD), is examined using cyclic and square wave voltammetry in 0.05 M NaHCO3 and phosphate buffer (pH=11) on a gold electrode. The voltammograms show a single irreversible anodic wave with the current controlled by adsorption. It was found that phosphate buffer favorites the electrochemical activity of both complexes of Nif with the linear dependency of the oxidative currents on their concentrations. In phosphate buffer, only HP beta CD-Aml complex showed linear dependency of the oxidative currents on the concentration. In 0.05 M NaHCO3 as electrolyte only HP beta CD-Nif exhibited apparent activity. The initial potential of the anodic reaction as well as the value of the potential for anodic currents maximum of all the examined complexes in both electrolytes were shifted to the positive direction compared to their standards. In addition, the value of anodic currents decreased.
PB  - Esg, Belgrade
T2  - International Journal of Electrochemical Science
T1  - The Electrochemical Investigation of Inclusion Complexes of Nifedipine and Amlodipine with beta-Cyclodextrin and (2-Hydroxypropyl)-beta-Cyclodextrin
VL  - 8
IS  - 7
SP  - 9543
EP  - 9557
UR  - https://hdl.handle.net/21.15107/rcub_cer_1221
ER  - 

@article{
author = "Stoiljković, Zora and Jovanović, Vladislava M. and Mijin, Dušan and Nikolić, V. and Nikolic, Lj. and Petrović, Slobodan D. and Avramov Ivić, Milka",
year = "2013",
abstract = "The electrochemical behavior of inclusion complexes of nifedipine (Nif) and amlodipine (Aml), a long-acting calcium channel blockers dihydropyridine (DHP) class, with beta-cyclodextrin (beta CD) and (2-hydroxypropyl)-beta-cyclodextrin (HP beta CD), is examined using cyclic and square wave voltammetry in 0.05 M NaHCO3 and phosphate buffer (pH=11) on a gold electrode. The voltammograms show a single irreversible anodic wave with the current controlled by adsorption. It was found that phosphate buffer favorites the electrochemical activity of both complexes of Nif with the linear dependency of the oxidative currents on their concentrations. In phosphate buffer, only HP beta CD-Aml complex showed linear dependency of the oxidative currents on the concentration. In 0.05 M NaHCO3 as electrolyte only HP beta CD-Nif exhibited apparent activity. The initial potential of the anodic reaction as well as the value of the potential for anodic currents maximum of all the examined complexes in both electrolytes were shifted to the positive direction compared to their standards. In addition, the value of anodic currents decreased.",
publisher = "Esg, Belgrade",
journal = "International Journal of Electrochemical Science",
title = "The Electrochemical Investigation of Inclusion Complexes of Nifedipine and Amlodipine with beta-Cyclodextrin and (2-Hydroxypropyl)-beta-Cyclodextrin",
volume = "8",
number = "7",
pages = "9543-9557",
url = "https://hdl.handle.net/21.15107/rcub_cer_1221"
}

Stoiljković, Z., Jovanović, V. M., Mijin, D., Nikolić, V., Nikolic, Lj., Petrović, S. D.,& Avramov Ivić, M.. (2013). The Electrochemical Investigation of Inclusion Complexes of Nifedipine and Amlodipine with beta-Cyclodextrin and (2-Hydroxypropyl)-beta-Cyclodextrin. in International Journal of Electrochemical Science
Esg, Belgrade., 8(7), 9543-9557.
https://hdl.handle.net/21.15107/rcub_cer_1221

Stoiljković Z, Jovanović VM, Mijin D, Nikolić V, Nikolic L, Petrović SD, Avramov Ivić M. The Electrochemical Investigation of Inclusion Complexes of Nifedipine and Amlodipine with beta-Cyclodextrin and (2-Hydroxypropyl)-beta-Cyclodextrin. in International Journal of Electrochemical Science. 2013;8(7):9543-9557.
https://hdl.handle.net/21.15107/rcub_cer_1221 .

Stoiljković, Zora, Jovanović, Vladislava M., Mijin, Dušan, Nikolić, V., Nikolic, Lj., Petrović, Slobodan D., Avramov Ivić, Milka, "The Electrochemical Investigation of Inclusion Complexes of Nifedipine and Amlodipine with beta-Cyclodextrin and (2-Hydroxypropyl)-beta-Cyclodextrin" in International Journal of Electrochemical Science, 8, no. 7 (2013):9543-9557,
https://hdl.handle.net/21.15107/rcub_cer_1221 .

TY  - JOUR
AU  - Nikolic, L.
AU  - Ristic, I.
AU  - Stojiljkovic, S.
AU  - Vuković, Zorica
AU  - Stojiljkovic, D.
AU  - Nikolić, V.
AU  - Budinski-Simendic, J.
PY  - 2012
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1149
AB  - In this work a new class of functional composites was prepared based on the organically modificated montmorillonite and methacrylic acid. In the first step, the native montmorillonite was mixed with poly(ethylenimine) monomer to promote the intercalation process. In the second step, the methacrylic acid and initiator (potassium persulfate) were added and polymerization was carried out at 80°C for 2 hours. Characterization of the obtained composite material was performed by Fourier transform infrared spectroscopy. The change in interlamellar spacing of montmorillonite after polymer composite preparation was determined by X-ray diffraction. In prepared composite samples the existence of two crystalline phases was estimated by X-ray measurements. In the first, the poly(methacrylic acid) chains are intercalated within the montmorillonite layers, and in the second, they are dispersed in the polymer matrix. The influence of montmorillonite on the thermal properties of the obtained composites was measured using the combined thermogravimetry and differential scanning calorimetry method. The porosity of the prepared samples was determined by isotherm adsorption and the desorption of nitrogen (Brunauer-Emmett-Teller method). It was assessed that a certain amount of polymer is deposited on the montmorillonite and thus covering of the micropores and partially covering of the mesopores was achieved.
T2  - Journal of Composite Materials
T1  - The influence of montmorillonite modification on the properties of composite material based on poly(methacrylic acid)
VL  - 46
IS  - 8
SP  - 921
EP  - 928
DO  - 10.1177/0021998311412987
ER  - 

@article{
author = "Nikolic, L. and Ristic, I. and Stojiljkovic, S. and Vuković, Zorica and Stojiljkovic, D. and Nikolić, V. and Budinski-Simendic, J.",
year = "2012",
abstract = "In this work a new class of functional composites was prepared based on the organically modificated montmorillonite and methacrylic acid. In the first step, the native montmorillonite was mixed with poly(ethylenimine) monomer to promote the intercalation process. In the second step, the methacrylic acid and initiator (potassium persulfate) were added and polymerization was carried out at 80°C for 2 hours. Characterization of the obtained composite material was performed by Fourier transform infrared spectroscopy. The change in interlamellar spacing of montmorillonite after polymer composite preparation was determined by X-ray diffraction. In prepared composite samples the existence of two crystalline phases was estimated by X-ray measurements. In the first, the poly(methacrylic acid) chains are intercalated within the montmorillonite layers, and in the second, they are dispersed in the polymer matrix. The influence of montmorillonite on the thermal properties of the obtained composites was measured using the combined thermogravimetry and differential scanning calorimetry method. The porosity of the prepared samples was determined by isotherm adsorption and the desorption of nitrogen (Brunauer-Emmett-Teller method). It was assessed that a certain amount of polymer is deposited on the montmorillonite and thus covering of the micropores and partially covering of the mesopores was achieved.",
journal = "Journal of Composite Materials",
title = "The influence of montmorillonite modification on the properties of composite material based on poly(methacrylic acid)",
volume = "46",
number = "8",
pages = "921-928",
doi = "10.1177/0021998311412987"
}

Nikolic, L., Ristic, I., Stojiljkovic, S., Vuković, Z., Stojiljkovic, D., Nikolić, V.,& Budinski-Simendic, J.. (2012). The influence of montmorillonite modification on the properties of composite material based on poly(methacrylic acid). in Journal of Composite Materials, 46(8), 921-928.
https://doi.org/10.1177/0021998311412987

Nikolic L, Ristic I, Stojiljkovic S, Vuković Z, Stojiljkovic D, Nikolić V, Budinski-Simendic J. The influence of montmorillonite modification on the properties of composite material based on poly(methacrylic acid). in Journal of Composite Materials. 2012;46(8):921-928.
doi:10.1177/0021998311412987 .

Nikolic, L., Ristic, I., Stojiljkovic, S., Vuković, Zorica, Stojiljkovic, D., Nikolić, V., Budinski-Simendic, J., "The influence of montmorillonite modification on the properties of composite material based on poly(methacrylic acid)" in Journal of Composite Materials, 46, no. 8 (2012):921-928,
https://doi.org/10.1177/0021998311412987 . .

TY  - JOUR
AU  - Nikolić, V.
AU  - Jokanović, V.
AU  - Radić, Nenad
AU  - Grbić, Boško
AU  - Jokanović, B.
AU  - Izvonar, D.
PY  - 2009
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/607
AB  - The mechanism of the synthesis of silicon dioxide thin films on the surface of a stainless steel band substrate, by thermal spraying of a silica sol as a precursor was the subject of this work. The structural design of the hydro thermally obtained particles was defined as an organized structure of basic motives-silica tetrahedrons, over silica chains and finally sol particles, which were used as a well-defined precursor for the preparation of corresponding thin films. IR spectroscopy and TGA analysis were employed to define the structure of the silica tetrahedrons and the size of the silica chains in the sol particles. The thickness of the film and the dependence of the film morphology and structure on its surface and of its cross section were investigated. The mechanism of film formation and the differences on its appearance depending of the SiO2 sol concentration was also investigated. The sizes of the particles were 50 - 250 nm, while the agglomerate sizes were mostly 250 nm in diameter and 1 - 2 μm in the length. The thicknesses of the films were 6.5 - 33 μm.
T2  - Journal of Optoelectronics and Advanced Materials
T1  - SiO2 thin films obtained from silica sols by thermal spraying
VL  - 11
IS  - 3
SP  - 243
EP  - 250
UR  - https://hdl.handle.net/21.15107/rcub_cer_607
ER  - 

@article{
author = "Nikolić, V. and Jokanović, V. and Radić, Nenad and Grbić, Boško and Jokanović, B. and Izvonar, D.",
year = "2009",
abstract = "The mechanism of the synthesis of silicon dioxide thin films on the surface of a stainless steel band substrate, by thermal spraying of a silica sol as a precursor was the subject of this work. The structural design of the hydro thermally obtained particles was defined as an organized structure of basic motives-silica tetrahedrons, over silica chains and finally sol particles, which were used as a well-defined precursor for the preparation of corresponding thin films. IR spectroscopy and TGA analysis were employed to define the structure of the silica tetrahedrons and the size of the silica chains in the sol particles. The thickness of the film and the dependence of the film morphology and structure on its surface and of its cross section were investigated. The mechanism of film formation and the differences on its appearance depending of the SiO2 sol concentration was also investigated. The sizes of the particles were 50 - 250 nm, while the agglomerate sizes were mostly 250 nm in diameter and 1 - 2 μm in the length. The thicknesses of the films were 6.5 - 33 μm.",
journal = "Journal of Optoelectronics and Advanced Materials",
title = "SiO2 thin films obtained from silica sols by thermal spraying",
volume = "11",
number = "3",
pages = "243-250",
url = "https://hdl.handle.net/21.15107/rcub_cer_607"
}

Nikolić, V., Jokanović, V., Radić, N., Grbić, B., Jokanović, B.,& Izvonar, D.. (2009). SiO2 thin films obtained from silica sols by thermal spraying. in Journal of Optoelectronics and Advanced Materials, 11(3), 243-250.
https://hdl.handle.net/21.15107/rcub_cer_607

Nikolić V, Jokanović V, Radić N, Grbić B, Jokanović B, Izvonar D. SiO2 thin films obtained from silica sols by thermal spraying. in Journal of Optoelectronics and Advanced Materials. 2009;11(3):243-250.
https://hdl.handle.net/21.15107/rcub_cer_607 .

Nikolić, V., Jokanović, V., Radić, Nenad, Grbić, Boško, Jokanović, B., Izvonar, D., "SiO2 thin films obtained from silica sols by thermal spraying" in Journal of Optoelectronics and Advanced Materials, 11, no. 3 (2009):243-250,
https://hdl.handle.net/21.15107/rcub_cer_607 .