TY  - JOUR
AU  - Ivanović, Marija
AU  - Knežević, Sanja
AU  - Radović, Ivona
AU  - Kljajević, Ljiljana
AU  - Mirković, Miljana
AU  - Nenadović, Miloš
AU  - Nenadović, Snežana
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6311
AB  - Geopolymers have excellent physical and mechanical properties, so they can be used as a substitute for ordinary polymers. Geopolymers are ceramic materials, which exhibit the property of brittleness, which can be a limitation in some structural applications. To overcome this shortcoming, a new group of materials (organic geopolymers) was developed. The aim of this work is the synthesis of organic (hybrid) geopolymers. A geopolymer based on metakaolin was synthesized as a reference sample, while polyvinyl alcohol was added as an organic phase for synthesizing a hybrid geopolymer. It was concluded that the systems follow the rule of behavior in liquid systems. The chemical composition of the samples was determined by X-ray fluorescence analysis (XRF). Structural and phase characterization of hybrid and reference materials were analyzed using X-ray diffraction (XRD)and Fourier-transform infrared spectroscopy (FTIR), which revealed new phases in the PVA-added samples. The results show that the content of added PVA in the reaction mixture affects the phase composition of the synthesized materials. To examine the possibility of adsorption of the samples, Ultraviolet-visible spectroscopy (UV/VIS) was used. The morphology was analyzed using a scanning electron microscope with energy dispersive spectroscopy (SEM/EDS), where efflorescence was observed and identified. After characterizing the geopolymer with the addition of PVA, we obtained a material that was far more porous than the basic sample, and we can conclude that we have synthesized a material that shows good mechanical properties.
PB  - MDPI
T2  - Sustainability (Switzerland)
T1  - Preparation and Characterization of Geopolymers Based on Metakaolin with the Addition of Organic Phase PVA
IS  - 5
SP  - 4441
VL  - 15
DO  - 10.3390/su15054441
ER  - 

@article{
author = "Ivanović, Marija and Knežević, Sanja and Radović, Ivona and Kljajević, Ljiljana and Mirković, Miljana and Nenadović, Miloš and Nenadović, Snežana",
year = "2023",
abstract = "Geopolymers have excellent physical and mechanical properties, so they can be used as a substitute for ordinary polymers. Geopolymers are ceramic materials, which exhibit the property of brittleness, which can be a limitation in some structural applications. To overcome this shortcoming, a new group of materials (organic geopolymers) was developed. The aim of this work is the synthesis of organic (hybrid) geopolymers. A geopolymer based on metakaolin was synthesized as a reference sample, while polyvinyl alcohol was added as an organic phase for synthesizing a hybrid geopolymer. It was concluded that the systems follow the rule of behavior in liquid systems. The chemical composition of the samples was determined by X-ray fluorescence analysis (XRF). Structural and phase characterization of hybrid and reference materials were analyzed using X-ray diffraction (XRD)and Fourier-transform infrared spectroscopy (FTIR), which revealed new phases in the PVA-added samples. The results show that the content of added PVA in the reaction mixture affects the phase composition of the synthesized materials. To examine the possibility of adsorption of the samples, Ultraviolet-visible spectroscopy (UV/VIS) was used. The morphology was analyzed using a scanning electron microscope with energy dispersive spectroscopy (SEM/EDS), where efflorescence was observed and identified. After characterizing the geopolymer with the addition of PVA, we obtained a material that was far more porous than the basic sample, and we can conclude that we have synthesized a material that shows good mechanical properties.",
publisher = "MDPI",
journal = "Sustainability (Switzerland)",
title = "Preparation and Characterization of Geopolymers Based on Metakaolin with the Addition of Organic Phase PVA",
number = "5",
pages = "4441",
volume = "15",
doi = "10.3390/su15054441"
}

Ivanović, M., Knežević, S., Radović, I., Kljajević, L., Mirković, M., Nenadović, M.,& Nenadović, S.. (2023). Preparation and Characterization of Geopolymers Based on Metakaolin with the Addition of Organic Phase PVA. in Sustainability (Switzerland)
MDPI., 15(5), 4441.
https://doi.org/10.3390/su15054441

Ivanović M, Knežević S, Radović I, Kljajević L, Mirković M, Nenadović M, Nenadović S. Preparation and Characterization of Geopolymers Based on Metakaolin with the Addition of Organic Phase PVA. in Sustainability (Switzerland). 2023;15(5):4441.
doi:10.3390/su15054441 .

Ivanović, Marija, Knežević, Sanja, Radović, Ivona, Kljajević, Ljiljana, Mirković, Miljana, Nenadović, Miloš, Nenadović, Snežana, "Preparation and Characterization of Geopolymers Based on Metakaolin with the Addition of Organic Phase PVA" in Sustainability (Switzerland), 15, no. 5 (2023):4441,
https://doi.org/10.3390/su15054441 . .

TY  - JOUR
AU  - Mladenović Nikolić, Nataša N.
AU  - Kandić, Aleksandar B.
AU  - Trivunac, Katarina V.
AU  - Mirković, Miljana M.
AU  - Vukanac, Ivana S.
AU  - Nenadović, Snežana S.
AU  - Kljajević, Ljiljana M.
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5245
AB  - The aim of the presented research was to investigate the application possibility of wood ash and metakaolin to obtain alkali-activated materials as relatively new materials in the building industry. Thus, in order to assess the adequate use of these waste materials, structural and radiological characteristics should be considered. Until now, the focus has been on ash from thermal power plants produced by burning coal, but a large part of households in our country have individual fireplaces in which wood is used as the basic raw material; thus, it is very interesting to measure the activity concentration of radionuclide in wood ash as well as the possibility of reusing that ash for other purposes. All materials were studied, in terms of physical and chemical characteristics, by methods such as X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy, and scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). XRD measurements of wood ash samples showed that it consists of calcite and larnite. FTIR spectroscopy revealed a polymeric Si–O–Al framework in alkali-activated materials and Si–O bonding bands corresponding to silicon dioxide. Determination of radionuclide content was performed by means of gamma-ray spectrometry. Results showed that the alkaline activation process led to the decrease in the activity concentration of radionuclides detected in the measured samples. External radiation hazard index (Hex) for wood ash was reduced by more than 50% after alkali activation. The results of activity concentration measurements in alkali-activated materials indicate potential for their safe application in building construction.
PB  - MDPI
T2  - Sustainability (Switzerland)
T1  - Radiological and Structural Characterization of Raw and Alkali-Activated Wood Ash and Metakaolin Blends
IS  - 20
SP  - 12960
VL  - 14
DO  - 10.3390/su142012960
ER  - 

@article{
author = "Mladenović Nikolić, Nataša N. and Kandić, Aleksandar B. and Trivunac, Katarina V. and Mirković, Miljana M. and Vukanac, Ivana S. and Nenadović, Snežana S. and Kljajević, Ljiljana M.",
year = "2022",
abstract = "The aim of the presented research was to investigate the application possibility of wood ash and metakaolin to obtain alkali-activated materials as relatively new materials in the building industry. Thus, in order to assess the adequate use of these waste materials, structural and radiological characteristics should be considered. Until now, the focus has been on ash from thermal power plants produced by burning coal, but a large part of households in our country have individual fireplaces in which wood is used as the basic raw material; thus, it is very interesting to measure the activity concentration of radionuclide in wood ash as well as the possibility of reusing that ash for other purposes. All materials were studied, in terms of physical and chemical characteristics, by methods such as X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy, and scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). XRD measurements of wood ash samples showed that it consists of calcite and larnite. FTIR spectroscopy revealed a polymeric Si–O–Al framework in alkali-activated materials and Si–O bonding bands corresponding to silicon dioxide. Determination of radionuclide content was performed by means of gamma-ray spectrometry. Results showed that the alkaline activation process led to the decrease in the activity concentration of radionuclides detected in the measured samples. External radiation hazard index (Hex) for wood ash was reduced by more than 50% after alkali activation. The results of activity concentration measurements in alkali-activated materials indicate potential for their safe application in building construction.",
publisher = "MDPI",
journal = "Sustainability (Switzerland)",
title = "Radiological and Structural Characterization of Raw and Alkali-Activated Wood Ash and Metakaolin Blends",
number = "20",
pages = "12960",
volume = "14",
doi = "10.3390/su142012960"
}

Mladenović Nikolić, N. N., Kandić, A. B., Trivunac, K. V., Mirković, M. M., Vukanac, I. S., Nenadović, S. S.,& Kljajević, L. M.. (2022). Radiological and Structural Characterization of Raw and Alkali-Activated Wood Ash and Metakaolin Blends. in Sustainability (Switzerland)
MDPI., 14(20), 12960.
https://doi.org/10.3390/su142012960

Mladenović Nikolić NN, Kandić AB, Trivunac KV, Mirković MM, Vukanac IS, Nenadović SS, Kljajević LM. Radiological and Structural Characterization of Raw and Alkali-Activated Wood Ash and Metakaolin Blends. in Sustainability (Switzerland). 2022;14(20):12960.
doi:10.3390/su142012960 .

Mladenović Nikolić, Nataša N., Kandić, Aleksandar B., Trivunac, Katarina V., Mirković, Miljana M., Vukanac, Ivana S., Nenadović, Snežana S., Kljajević, Ljiljana M., "Radiological and Structural Characterization of Raw and Alkali-Activated Wood Ash and Metakaolin Blends" in Sustainability (Switzerland), 14, no. 20 (2022):12960,
https://doi.org/10.3390/su142012960 . .

TY  - CONF
AU  - Maletić, Marina
AU  - Živojinović, Sara
AU  - Mladenović Nikolić, Nataša
AU  - Kljajević, Ljiljana
AU  - Nenadović, Snežana S.
AU  - Vukčević, Marija
AU  - Trivunac, Katarina
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6307
AB  - Metilensko plavo se često koristi u tekstilnoj, kozmetičkoj, papirnoj, kožnoj,
farmaceutskoj i prehrambenoj industriji, pri čemu kao rezultat nastaju značajne količine otpadne
vode. Prisustvo boja u vodenom ekosistemu onemogućava prolazak sunčevih zraka u dublje slojeve,
zbog čega se smanjuje fotosinteza, kvalitet vode i rastvorljivost gasova, pa dolazi do akutnog
trovanja flore i faune. Zbog toga se primenjuju različite metode za uklanjanje obojenih supstanci
pre ispuštanja u prirodne recipijente, među kojima se izdvaja adsorpcija na prirodnim
materijalima. U ovom radu ispitana je mogućnost uklanjanja katjonske boje metilensko plavo iz
vodenih rastvora adsorpcijom na modifikovanoj dijatomejskoj zemlji. Prvo je izvršena hemijska
modifikacija sa barijum-karbonatom, a zatim je dobijeni materijal termički modifikovan na
temperaturi od 900ºC pri čemu je karbonat preveden u barijum-oksid. Ovako pripremljeni
adsorbenti su korišćeni za uklanjanje metilensko plavog iz vodenog rastvora. Pokazano je da
hemijski modifikovana dijatomejska zemlja ima veći afinitet prema katjonskim bojama i da je
adsorpcija bolja u neutralnoj i baznoj sredini.
PB  - Akademija tehničkih strukovnih studija "Beograd"
C3  - Šesti naučno-stručni skup Politehnika, Zbornik radova
T1  - Određivanje efikasnosti adsorbenata na bazi modifikovane dijatomejske zemlje za adsorpciju katjonske boje metilensko plavo
EP  - 129
SP  - 124
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6307
ER  - 

@conference{
author = "Maletić, Marina and Živojinović, Sara and Mladenović Nikolić, Nataša and Kljajević, Ljiljana and Nenadović, Snežana S. and Vukčević, Marija and Trivunac, Katarina",
year = "2021",
abstract = "Metilensko plavo se često koristi u tekstilnoj, kozmetičkoj, papirnoj, kožnoj,
farmaceutskoj i prehrambenoj industriji, pri čemu kao rezultat nastaju značajne količine otpadne
vode. Prisustvo boja u vodenom ekosistemu onemogućava prolazak sunčevih zraka u dublje slojeve,
zbog čega se smanjuje fotosinteza, kvalitet vode i rastvorljivost gasova, pa dolazi do akutnog
trovanja flore i faune. Zbog toga se primenjuju različite metode za uklanjanje obojenih supstanci
pre ispuštanja u prirodne recipijente, među kojima se izdvaja adsorpcija na prirodnim
materijalima. U ovom radu ispitana je mogućnost uklanjanja katjonske boje metilensko plavo iz
vodenih rastvora adsorpcijom na modifikovanoj dijatomejskoj zemlji. Prvo je izvršena hemijska
modifikacija sa barijum-karbonatom, a zatim je dobijeni materijal termički modifikovan na
temperaturi od 900ºC pri čemu je karbonat preveden u barijum-oksid. Ovako pripremljeni
adsorbenti su korišćeni za uklanjanje metilensko plavog iz vodenog rastvora. Pokazano je da
hemijski modifikovana dijatomejska zemlja ima veći afinitet prema katjonskim bojama i da je
adsorpcija bolja u neutralnoj i baznoj sredini.",
publisher = "Akademija tehničkih strukovnih studija "Beograd"",
journal = "Šesti naučno-stručni skup Politehnika, Zbornik radova",
title = "Određivanje efikasnosti adsorbenata na bazi modifikovane dijatomejske zemlje za adsorpciju katjonske boje metilensko plavo",
pages = "129-124",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6307"
}

Maletić, M., Živojinović, S., Mladenović Nikolić, N., Kljajević, L., Nenadović, S. S., Vukčević, M.,& Trivunac, K.. (2021). Određivanje efikasnosti adsorbenata na bazi modifikovane dijatomejske zemlje za adsorpciju katjonske boje metilensko plavo. in Šesti naučno-stručni skup Politehnika, Zbornik radova
Akademija tehničkih strukovnih studija "Beograd"., 124-129.
https://hdl.handle.net/21.15107/rcub_technorep_6307

Maletić M, Živojinović S, Mladenović Nikolić N, Kljajević L, Nenadović SS, Vukčević M, Trivunac K. Određivanje efikasnosti adsorbenata na bazi modifikovane dijatomejske zemlje za adsorpciju katjonske boje metilensko plavo. in Šesti naučno-stručni skup Politehnika, Zbornik radova. 2021;:124-129.
https://hdl.handle.net/21.15107/rcub_technorep_6307 .

Maletić, Marina, Živojinović, Sara, Mladenović Nikolić, Nataša, Kljajević, Ljiljana, Nenadović, Snežana S., Vukčević, Marija, Trivunac, Katarina, "Određivanje efikasnosti adsorbenata na bazi modifikovane dijatomejske zemlje za adsorpciju katjonske boje metilensko plavo" in Šesti naučno-stručni skup Politehnika, Zbornik radova (2021):124-129,
https://hdl.handle.net/21.15107/rcub_technorep_6307 .

TY  - JOUR
AU  - Ivanović, Marija
AU  - Nenadović, Snežana S.
AU  - Pavlović, Vera P.
AU  - Radović, Ivona R.
AU  - Kijevčanin, Mirjana Lj.
AU  - Pavlović, Vladimir B.
AU  - Kljajević, Ljiljana M.
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5121
AB  - Thermodynamic parameters (densities, viscosities, speed of sound, and refractive index) of four series of alkaline activators were determined over the temperature range from 15 to 60 °C for the process of geopolymerization. Mixtures of Na2SiO3and NaOH of different molar concentrations (from 2M to 8M with step 2) were used as an alkaline activator. The sample with the highest NaOH concentrationalso shows the highest values of all thermodynamic parameters.Metakaolin, obtained by calcination of kaolin at 750 °C, was used as the starting material.The samples were characterized by X-ray diffraction (XRD),FTIR and Raman spectroscopy, Scanning Electron Microscopy (SEM), and Energy-Dispersive X-Ray (EDX) Spectroscopy. Results of FTIR analysis correlated with results of Raman Spectroscopy. Due to the polymerization process, the changes in the phonon spectrum were confirmed. The different concentra-tions of activators do not notably change the Si/Al ratio.
T2  - Macedonian Journal of Chemistry and Chemical Engineering
T1  - The influence of thermodynamic parameters on alkaline activator of geopolymers and structure of geopolymers
IS  - 1
SP  - 99
VL  - 40
DO  - 10.20450/mjcce.2021.2127
ER  - 

@article{
author = "Ivanović, Marija and Nenadović, Snežana S. and Pavlović, Vera P. and Radović, Ivona R. and Kijevčanin, Mirjana Lj. and Pavlović, Vladimir B. and Kljajević, Ljiljana M.",
year = "2021",
abstract = "Thermodynamic parameters (densities, viscosities, speed of sound, and refractive index) of four series of alkaline activators were determined over the temperature range from 15 to 60 °C for the process of geopolymerization. Mixtures of Na2SiO3and NaOH of different molar concentrations (from 2M to 8M with step 2) were used as an alkaline activator. The sample with the highest NaOH concentrationalso shows the highest values of all thermodynamic parameters.Metakaolin, obtained by calcination of kaolin at 750 °C, was used as the starting material.The samples were characterized by X-ray diffraction (XRD),FTIR and Raman spectroscopy, Scanning Electron Microscopy (SEM), and Energy-Dispersive X-Ray (EDX) Spectroscopy. Results of FTIR analysis correlated with results of Raman Spectroscopy. Due to the polymerization process, the changes in the phonon spectrum were confirmed. The different concentra-tions of activators do not notably change the Si/Al ratio.",
journal = "Macedonian Journal of Chemistry and Chemical Engineering",
title = "The influence of thermodynamic parameters on alkaline activator of geopolymers and structure of geopolymers",
number = "1",
pages = "99",
volume = "40",
doi = "10.20450/mjcce.2021.2127"
}

Ivanović, M., Nenadović, S. S., Pavlović, V. P., Radović, I. R., Kijevčanin, M. Lj., Pavlović, V. B.,& Kljajević, L. M.. (2021). The influence of thermodynamic parameters on alkaline activator of geopolymers and structure of geopolymers. in Macedonian Journal of Chemistry and Chemical Engineering, 40(1), 99.
https://doi.org/10.20450/mjcce.2021.2127

Ivanović M, Nenadović SS, Pavlović VP, Radović IR, Kijevčanin ML, Pavlović VB, Kljajević LM. The influence of thermodynamic parameters on alkaline activator of geopolymers and structure of geopolymers. in Macedonian Journal of Chemistry and Chemical Engineering. 2021;40(1):99.
doi:10.20450/mjcce.2021.2127 .

Ivanović, Marija, Nenadović, Snežana S., Pavlović, Vera P., Radović, Ivona R., Kijevčanin, Mirjana Lj., Pavlović, Vladimir B., Kljajević, Ljiljana M., "The influence of thermodynamic parameters on alkaline activator of geopolymers and structure of geopolymers" in Macedonian Journal of Chemistry and Chemical Engineering, 40, no. 1 (2021):99,
https://doi.org/10.20450/mjcce.2021.2127 . .

TY  - JOUR
AU  - Mladenović, Nataša N.
AU  - Kljajević, Ljiljana M.
AU  - Nenadović, Snežana S.
AU  - Ivanović, Marija D.
AU  - Čalija, Bojan
AU  - Gulicovski, Jelena
AU  - Trivunac, Katarina
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4492
AB  - Fundamental research of inorganic polymers prepared from available aluminosilicate precursors represent an innovative class of materials characterized by low energy consumption for production. This is just one of the reasons why their use is focused in protecting the environment for removing of heavy metals from aqueous solutions. The concentration of hydroxide as activator solution plays an important role in the geopolymerization process. The present study examined the use of geopolymer materials, obtained in reaction of geopolymerizations of metakaolin as precursor activated with NaOH concentration 2.0, 4.0, 6.0 and 8.0 mol/dm(3) for removal of cadmium ions from aqueous solutions. The structure and properties of the obtained geopolymer samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflection infrared spectroscopy (DRIFTS). To investigate the surface charge of geopolymers the zeta potential measurements were performed. Batch adsorption experiments conducted at room temperature (23 +/- 1 degrees C) showed that the adsorption pattern followed the Freundlich isotherm model. The maximum removal of cadmium obtained from batch studies was 84.1% for GP6M at pH approximate to 6.7. The results generally showed that geopolymer samples could be considered as a potential adsorbent for cadmium removal from aqueous solutions.
PB  - Springer, Dordrecht
T2  - Journal of Inorganic and Organometallic Polymers and Materials
T1  - The Applications of New Inorganic Polymer for Adsorption Cadmium from Waste Water
EP  - 563
IS  - 2
SP  - 554
VL  - 30
DO  - 10.1007/s10904-019-01215-y
ER  - 

@article{
author = "Mladenović, Nataša N. and Kljajević, Ljiljana M. and Nenadović, Snežana S. and Ivanović, Marija D. and Čalija, Bojan and Gulicovski, Jelena and Trivunac, Katarina",
year = "2020",
abstract = "Fundamental research of inorganic polymers prepared from available aluminosilicate precursors represent an innovative class of materials characterized by low energy consumption for production. This is just one of the reasons why their use is focused in protecting the environment for removing of heavy metals from aqueous solutions. The concentration of hydroxide as activator solution plays an important role in the geopolymerization process. The present study examined the use of geopolymer materials, obtained in reaction of geopolymerizations of metakaolin as precursor activated with NaOH concentration 2.0, 4.0, 6.0 and 8.0 mol/dm(3) for removal of cadmium ions from aqueous solutions. The structure and properties of the obtained geopolymer samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflection infrared spectroscopy (DRIFTS). To investigate the surface charge of geopolymers the zeta potential measurements were performed. Batch adsorption experiments conducted at room temperature (23 +/- 1 degrees C) showed that the adsorption pattern followed the Freundlich isotherm model. The maximum removal of cadmium obtained from batch studies was 84.1% for GP6M at pH approximate to 6.7. The results generally showed that geopolymer samples could be considered as a potential adsorbent for cadmium removal from aqueous solutions.",
publisher = "Springer, Dordrecht",
journal = "Journal of Inorganic and Organometallic Polymers and Materials",
title = "The Applications of New Inorganic Polymer for Adsorption Cadmium from Waste Water",
pages = "563-554",
number = "2",
volume = "30",
doi = "10.1007/s10904-019-01215-y"
}

Mladenović, N. N., Kljajević, L. M., Nenadović, S. S., Ivanović, M. D., Čalija, B., Gulicovski, J.,& Trivunac, K.. (2020). The Applications of New Inorganic Polymer for Adsorption Cadmium from Waste Water. in Journal of Inorganic and Organometallic Polymers and Materials
Springer, Dordrecht., 30(2), 554-563.
https://doi.org/10.1007/s10904-019-01215-y

Mladenović NN, Kljajević LM, Nenadović SS, Ivanović MD, Čalija B, Gulicovski J, Trivunac K. The Applications of New Inorganic Polymer for Adsorption Cadmium from Waste Water. in Journal of Inorganic and Organometallic Polymers and Materials. 2020;30(2):554-563.
doi:10.1007/s10904-019-01215-y .

Mladenović, Nataša N., Kljajević, Ljiljana M., Nenadović, Snežana S., Ivanović, Marija D., Čalija, Bojan, Gulicovski, Jelena, Trivunac, Katarina, "The Applications of New Inorganic Polymer for Adsorption Cadmium from Waste Water" in Journal of Inorganic and Organometallic Polymers and Materials, 30, no. 2 (2020):554-563,
https://doi.org/10.1007/s10904-019-01215-y . .

TY  - JOUR
AU  - Bučevac, Dušan
AU  - Omerasević, Mia
AU  - Egelja, Adela
AU  - Radovanović, Željko
AU  - Kljajević, Ljiljana M.
AU  - Nenadović, Snežana S.
AU  - Krstić, Vladimir
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4525
AB  - Comprehensive study on effect of YAG amount on densification, creep resistance and room-temperature mechanical properties of Al2O3-YAG composite pressureless sintered at 1600 degrees C was conducted. The main goal was to optimize the amount of YAG in order to fabricate a composite with improved creep resistance and sufficiently good room-temperature mechanical properties. The composite was made by mixing a commercially available Al2O3 powder with fine YAG powder obtained by glycine-nitrate combustion synthesis starting from aluminum nitrate and yttrium nitrate. Increased driving force for sintering of fine YAG powder allowed fabrication of dense Al2O3-YAG composite with up to 30 vol% YAG. The presence of YAG was found to be very effective in improving creep resistance of Al2O3-YAG composite. Large Y3+ ions blocked diffusion along Al2O3 grain boundaries, reduced diffusivity and therefore enhanced creep resistance of Al2O3-YAG composite which continuously increased as the YAG amount increased. The presence of YAG was also found to improve mechanical properties such as hardness and elastic modulus. The improvement of these properties was ascribed to increased density of Al(2)O(3)YAG composites owing to high sintering activity of YAG powder. While fracture strength of the composite can be as high as that of monolithic Al2O3, fracture toughness of composite decreased continuously as the YAG content increased. The decrease was ascribed to transgranular fracture of both YAG and Al2O3 grains in samples containing larger amounts of YAG. The proper balance between fracture toughness and creep resistance was found in composite containing 18 vol% YAG which had considerably improved creep resistance accompanied by a relatively small decrease in fracture toughness.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Effect of YAG content on creep resistance and mechanical properties of Al2O3-YAG composite
EP  - 16007
IS  - 10
SP  - 15998
VL  - 46
DO  - 10.1016/j.ceramint.2020.03.150
ER  - 

@article{
author = "Bučevac, Dušan and Omerasević, Mia and Egelja, Adela and Radovanović, Željko and Kljajević, Ljiljana M. and Nenadović, Snežana S. and Krstić, Vladimir",
year = "2020",
abstract = "Comprehensive study on effect of YAG amount on densification, creep resistance and room-temperature mechanical properties of Al2O3-YAG composite pressureless sintered at 1600 degrees C was conducted. The main goal was to optimize the amount of YAG in order to fabricate a composite with improved creep resistance and sufficiently good room-temperature mechanical properties. The composite was made by mixing a commercially available Al2O3 powder with fine YAG powder obtained by glycine-nitrate combustion synthesis starting from aluminum nitrate and yttrium nitrate. Increased driving force for sintering of fine YAG powder allowed fabrication of dense Al2O3-YAG composite with up to 30 vol% YAG. The presence of YAG was found to be very effective in improving creep resistance of Al2O3-YAG composite. Large Y3+ ions blocked diffusion along Al2O3 grain boundaries, reduced diffusivity and therefore enhanced creep resistance of Al2O3-YAG composite which continuously increased as the YAG amount increased. The presence of YAG was also found to improve mechanical properties such as hardness and elastic modulus. The improvement of these properties was ascribed to increased density of Al(2)O(3)YAG composites owing to high sintering activity of YAG powder. While fracture strength of the composite can be as high as that of monolithic Al2O3, fracture toughness of composite decreased continuously as the YAG content increased. The decrease was ascribed to transgranular fracture of both YAG and Al2O3 grains in samples containing larger amounts of YAG. The proper balance between fracture toughness and creep resistance was found in composite containing 18 vol% YAG which had considerably improved creep resistance accompanied by a relatively small decrease in fracture toughness.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Effect of YAG content on creep resistance and mechanical properties of Al2O3-YAG composite",
pages = "16007-15998",
number = "10",
volume = "46",
doi = "10.1016/j.ceramint.2020.03.150"
}

Bučevac, D., Omerasević, M., Egelja, A., Radovanović, Ž., Kljajević, L. M., Nenadović, S. S.,& Krstić, V.. (2020). Effect of YAG content on creep resistance and mechanical properties of Al2O3-YAG composite. in Ceramics International
Elsevier Sci Ltd, Oxford., 46(10), 15998-16007.
https://doi.org/10.1016/j.ceramint.2020.03.150

Bučevac D, Omerasević M, Egelja A, Radovanović Ž, Kljajević LM, Nenadović SS, Krstić V. Effect of YAG content on creep resistance and mechanical properties of Al2O3-YAG composite. in Ceramics International. 2020;46(10):15998-16007.
doi:10.1016/j.ceramint.2020.03.150 .

Bučevac, Dušan, Omerasević, Mia, Egelja, Adela, Radovanović, Željko, Kljajević, Ljiljana M., Nenadović, Snežana S., Krstić, Vladimir, "Effect of YAG content on creep resistance and mechanical properties of Al2O3-YAG composite" in Ceramics International, 46, no. 10 (2020):15998-16007,
https://doi.org/10.1016/j.ceramint.2020.03.150 . .

TY  - JOUR
AU  - Ivanović, Marija
AU  - Kljajević, Ljiljana M.
AU  - Gulicovski, Jelena
AU  - Petković, Marijana
AU  - Janković-Častvan, Ivona
AU  - Bučevac, Dušan
AU  - Nenadović, Snežana S.
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4363
AB  - This paper outlines the production of an inorganic polymer/geopolymer using a metakaolin by an environmental friendly, energy saving, clean technology to conserve natural environment and resources. The influence of alkali activation, i.e. different concentration of NaOH as a component of alkali activator mixture on the process of geopolymerization of metakaolin is investigated. Also, process of aging time of geopolymer is followed by several analytical methods. The structure of metakaolin and metakaolin based geopolymers and their physicochemical properties were studied using X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FTIR) and after 28 days scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) was applied for the surface characterization of the samples. A shift of the Si-O or Si-O-X (X=Al, Si, Na...) bands as the molarity of activator increasing during geopolymerization process was observed by FTIR. Mass spectra of geopolymers were characterized by MALDI TOF mass spectrometer. Structural reorganization of geopolymer samples occurs during the curing/aging in accordance with a geopolymerization mechanism.
PB  - Međunarodni Institut za nauku o sinterovanju, Beograd
T2  - Science of Sintering
T1  - The Effect of the Concentration of Alkaline Activator and Aging Time on the Structure of Metakaolin Based Geopolymer
EP  - 229
IS  - 2
SP  - 219
VL  - 52
DO  - 10.2298/SOS2002219I
ER  - 

@article{
author = "Ivanović, Marija and Kljajević, Ljiljana M. and Gulicovski, Jelena and Petković, Marijana and Janković-Častvan, Ivona and Bučevac, Dušan and Nenadović, Snežana S.",
year = "2020",
abstract = "This paper outlines the production of an inorganic polymer/geopolymer using a metakaolin by an environmental friendly, energy saving, clean technology to conserve natural environment and resources. The influence of alkali activation, i.e. different concentration of NaOH as a component of alkali activator mixture on the process of geopolymerization of metakaolin is investigated. Also, process of aging time of geopolymer is followed by several analytical methods. The structure of metakaolin and metakaolin based geopolymers and their physicochemical properties were studied using X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FTIR) and after 28 days scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) was applied for the surface characterization of the samples. A shift of the Si-O or Si-O-X (X=Al, Si, Na...) bands as the molarity of activator increasing during geopolymerization process was observed by FTIR. Mass spectra of geopolymers were characterized by MALDI TOF mass spectrometer. Structural reorganization of geopolymer samples occurs during the curing/aging in accordance with a geopolymerization mechanism.",
publisher = "Međunarodni Institut za nauku o sinterovanju, Beograd",
journal = "Science of Sintering",
title = "The Effect of the Concentration of Alkaline Activator and Aging Time on the Structure of Metakaolin Based Geopolymer",
pages = "229-219",
number = "2",
volume = "52",
doi = "10.2298/SOS2002219I"
}

Ivanović, M., Kljajević, L. M., Gulicovski, J., Petković, M., Janković-Častvan, I., Bučevac, D.,& Nenadović, S. S.. (2020). The Effect of the Concentration of Alkaline Activator and Aging Time on the Structure of Metakaolin Based Geopolymer. in Science of Sintering
Međunarodni Institut za nauku o sinterovanju, Beograd., 52(2), 219-229.
https://doi.org/10.2298/SOS2002219I

Ivanović M, Kljajević LM, Gulicovski J, Petković M, Janković-Častvan I, Bučevac D, Nenadović SS. The Effect of the Concentration of Alkaline Activator and Aging Time on the Structure of Metakaolin Based Geopolymer. in Science of Sintering. 2020;52(2):219-229.
doi:10.2298/SOS2002219I .

Ivanović, Marija, Kljajević, Ljiljana M., Gulicovski, Jelena, Petković, Marijana, Janković-Častvan, Ivona, Bučevac, Dušan, Nenadović, Snežana S., "The Effect of the Concentration of Alkaline Activator and Aging Time on the Structure of Metakaolin Based Geopolymer" in Science of Sintering, 52, no. 2 (2020):219-229,
https://doi.org/10.2298/SOS2002219I . .

TY  - JOUR
AU  - Mladenović, Nataša N.
AU  - Ivanović, Marija M.
AU  - Kljajević, Ljiljana M.
AU  - Gulicovski, Jelena
AU  - Nenadović, Snežana S.
AU  - Trivunac, Katarina
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4298
AB  - Continuous development of new technologies leads to increasing pollution of water, thus creating the need for new materials that could be used in the processes of its purification. Therefore, adsorbents prepared from agricultural waste, resins, silica gels, zeolites, clays, flying ash, aluminosilicates and other materials are being investigated as potential sorbents. Recently, research has focused on improving the adsorption capacity by modifying the material by binding or impregnating inorganic and organic molecules on the surface. In this paper, the kaolinite modification with amino acids, histidine and cysteine, was performed to improve the efficiency of adsorption of cadmium ion. Cation exchange capacity (CEC) of raw and modified kaolinite was determined by titration with methylene blue. The influence of operating parameters, such as adsorption time, pH value of the solution, initial metal concentration and temperature, on the capacity and adsorption efficiency were examined. Better agreement of experimental results with Freundlich's adsorption isotherm and the pseudo-second order kinetics model suggest that the adsorption of cadmium ions on the investigated adsorbents takes place by chemisorption mechanism. The change of Gibbs free energy has a negative value for both adsorbents, which shows that the adsorption process is spontaneous. The efficacy of cadmium removal from the aqueous solution onto histidine-modified kaolinite increased from 78.6% to 91.8%.
AB  - Kontinualan razvoj novih tehnologija dovodi do povećanog zagađenja vode, čime se stvara potreba za novim materijalima koji se mogu koristiti u procesima prečišćavanja. Kao potencijalni, istražuju se adsorbenti pripremljeni od poljoprivrednog otpada, smola, silika gela, zeolita, gline, letećeg pepela, aluminosilikata i drugih materijala. Nedavna istraživanja su se fokusirala na poboljšanje adsorpcionog kapaciteta modifikovanjem materijala vezivanjem ili impregnacijom neorganskih i organskih molekula na površini. U ovom radu izvršena je modifikacija kaolinita aminokiselinama, histidinom i cisteinom, kako bi se poboljšala efikasnost adsorpcije jona kadmijuma. Kapacitet izmene katjona (CEC) sirovog i modifikovanog kaolinita određen je titracijom sa metilenskim plavim. Ispitivan je uticaj radnih parametara, kao što su vreme adsorpcije, pH vrednost rastvora, početna koncentracija metala, i temperatura, na kapacitet i efikasnost adsorpcije. Bolje slaganje eksperimentalnih rezultata sa Freundlich-ovom adsorpcionom izotermom i kinetičkim modelom pseudo-drugog reda sugeriše da se adsorpcija kadmijumovih jona na ispitivanim adsorbentima odvija putem hemisorpcionog mehanizma. Promena Gibsove slobodne energije ima negativnu vrednost za oba adsorbenta, što pokazuje da je proces adsorpcije spontan. Efikasnost uklanjanja kadmijuma iz vodenog rastvora na kaolinitu modifikovanim histidinom povećava se sa 78,6% na 91,8%.
PB  - Savez inženjera i tehničara Srbije, Beograd
T2  - Tehnika
T1  - Adsorption study of cadmium ions on kaolinite modified by histidine and cysteine
T1  - Adsorpcija kadmijumovih jona na kaolinitu modifikovanim histidinom i cisteinom
EP  - 22
IS  - 1
SP  - 15
VL  - 74
DO  - 10.5937/tehnika1901015M
ER  - 

@article{
author = "Mladenović, Nataša N. and Ivanović, Marija M. and Kljajević, Ljiljana M. and Gulicovski, Jelena and Nenadović, Snežana S. and Trivunac, Katarina",
year = "2019",
abstract = "Continuous development of new technologies leads to increasing pollution of water, thus creating the need for new materials that could be used in the processes of its purification. Therefore, adsorbents prepared from agricultural waste, resins, silica gels, zeolites, clays, flying ash, aluminosilicates and other materials are being investigated as potential sorbents. Recently, research has focused on improving the adsorption capacity by modifying the material by binding or impregnating inorganic and organic molecules on the surface. In this paper, the kaolinite modification with amino acids, histidine and cysteine, was performed to improve the efficiency of adsorption of cadmium ion. Cation exchange capacity (CEC) of raw and modified kaolinite was determined by titration with methylene blue. The influence of operating parameters, such as adsorption time, pH value of the solution, initial metal concentration and temperature, on the capacity and adsorption efficiency were examined. Better agreement of experimental results with Freundlich's adsorption isotherm and the pseudo-second order kinetics model suggest that the adsorption of cadmium ions on the investigated adsorbents takes place by chemisorption mechanism. The change of Gibbs free energy has a negative value for both adsorbents, which shows that the adsorption process is spontaneous. The efficacy of cadmium removal from the aqueous solution onto histidine-modified kaolinite increased from 78.6% to 91.8%., Kontinualan razvoj novih tehnologija dovodi do povećanog zagađenja vode, čime se stvara potreba za novim materijalima koji se mogu koristiti u procesima prečišćavanja. Kao potencijalni, istražuju se adsorbenti pripremljeni od poljoprivrednog otpada, smola, silika gela, zeolita, gline, letećeg pepela, aluminosilikata i drugih materijala. Nedavna istraživanja su se fokusirala na poboljšanje adsorpcionog kapaciteta modifikovanjem materijala vezivanjem ili impregnacijom neorganskih i organskih molekula na površini. U ovom radu izvršena je modifikacija kaolinita aminokiselinama, histidinom i cisteinom, kako bi se poboljšala efikasnost adsorpcije jona kadmijuma. Kapacitet izmene katjona (CEC) sirovog i modifikovanog kaolinita određen je titracijom sa metilenskim plavim. Ispitivan je uticaj radnih parametara, kao što su vreme adsorpcije, pH vrednost rastvora, početna koncentracija metala, i temperatura, na kapacitet i efikasnost adsorpcije. Bolje slaganje eksperimentalnih rezultata sa Freundlich-ovom adsorpcionom izotermom i kinetičkim modelom pseudo-drugog reda sugeriše da se adsorpcija kadmijumovih jona na ispitivanim adsorbentima odvija putem hemisorpcionog mehanizma. Promena Gibsove slobodne energije ima negativnu vrednost za oba adsorbenta, što pokazuje da je proces adsorpcije spontan. Efikasnost uklanjanja kadmijuma iz vodenog rastvora na kaolinitu modifikovanim histidinom povećava se sa 78,6% na 91,8%.",
publisher = "Savez inženjera i tehničara Srbije, Beograd",
journal = "Tehnika",
title = "Adsorption study of cadmium ions on kaolinite modified by histidine and cysteine, Adsorpcija kadmijumovih jona na kaolinitu modifikovanim histidinom i cisteinom",
pages = "22-15",
number = "1",
volume = "74",
doi = "10.5937/tehnika1901015M"
}

Mladenović, N. N., Ivanović, M. M., Kljajević, L. M., Gulicovski, J., Nenadović, S. S.,& Trivunac, K.. (2019). Adsorption study of cadmium ions on kaolinite modified by histidine and cysteine. in Tehnika
Savez inženjera i tehničara Srbije, Beograd., 74(1), 15-22.
https://doi.org/10.5937/tehnika1901015M

Mladenović NN, Ivanović MM, Kljajević LM, Gulicovski J, Nenadović SS, Trivunac K. Adsorption study of cadmium ions on kaolinite modified by histidine and cysteine. in Tehnika. 2019;74(1):15-22.
doi:10.5937/tehnika1901015M .

Mladenović, Nataša N., Ivanović, Marija M., Kljajević, Ljiljana M., Gulicovski, Jelena, Nenadović, Snežana S., Trivunac, Katarina, "Adsorption study of cadmium ions on kaolinite modified by histidine and cysteine" in Tehnika, 74, no. 1 (2019):15-22,
https://doi.org/10.5937/tehnika1901015M . .

TY  - JOUR
AU  - Mladenović, Nataša N.
AU  - Ivanović, Marija M.
AU  - Kljajević, Ljiljana M.
AU  - Nenadović, Snežana S.
AU  - Gulicovski, Jelena
AU  - Pavlović, Vera P.
AU  - Trivunac, Katarina
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3806
AB  - Alumosilicate polymers (geopolymers) based on metakaolin as precursor and alkaline activators of different concentrations (2M, 4M, 6M and 8M NaOH/Na2SiO3) were used to remove ions of cadmium from wastewater. Experiments were carried out in a batch process at room temperature (23 ± 1 ° C) for different operating parameters: adsorption time, pH value of solution, initial concentration of metal and mass of adsorbents. It was found that the optimum pH value for all adsorbents is above 6.0. The adsorption efficiency increases with increasing pH of the solution. With an increase in the initial concentration of cadmium, the adsorption capacity increases and reaches a value of over 200.0 mg/g. The experimental results have better agreement with Freundlich's adsorption isotherm (surface heterogeneity, hemisorption mechanism) and the pseudo-second order model (the principle of the chemisorption mechanism and adsorption rate depend on the adsorbent concentration). Alumosilicate geopolymer samples were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FTIR).
AB  - Za uklanjanje jona kadmijuma iz otpadnih voda korišćeni su alumosilikatni polimeri (geopolimeri) na bazi metakaolina kao prekursora i alkalni aktivator različitih koncentracija (2M, 4M, 6M i 8M NaOH/ Na2SiO3). Eksperimenti su vršeni u šaržnom procesu na sobnoj temperaturi (23±1 °C) pri različitim radnim parametrima: vreme adsorpcije, pH vrednost rastvora, početna koncentracija metala i masa adsorbenata. Utvrđeno je da je optimalna pH vrednost za sve adsorbente iznad 6,0. Efikasnost adsorpcije raste sa porastom pH vrednosti rastvora. Sa povećanjem početne koncentracije kadmijuma raste adsorpcioni kapacitet i dostiže vrednost preko 200,0 mg/g. Ekperimentalni rezultati su pokazali dobro slaganje sa Freundlich-ovom adsorpcionom izotermom i modelom pseudo-drugog reda. Karakterizacija geopolimera urađena je pomoću rendgenske difrakcije (XRD), skenirajuće elektronske mikroskopije (SEM) i infracrvene spektroskopije sa Furijeovom transformacijom (FTIR).
PB  - Savez inženjera i tehničara Srbije, Beograd
T2  - Tehnika
T1  - Application of alumosilicate polymers based on metakaolin in adsorption of cadmium ions from wastewater
T1  - Primena alumosilikatnih polimera na bazi metakaolina u adsorpciji jona kadmijuma iz otpadnih voda
EP  - 756
IS  - 6
SP  - 749
VL  - 73
DO  - 10.5937/tehnika1806749M
ER  - 

@article{
author = "Mladenović, Nataša N. and Ivanović, Marija M. and Kljajević, Ljiljana M. and Nenadović, Snežana S. and Gulicovski, Jelena and Pavlović, Vera P. and Trivunac, Katarina",
year = "2018",
abstract = "Alumosilicate polymers (geopolymers) based on metakaolin as precursor and alkaline activators of different concentrations (2M, 4M, 6M and 8M NaOH/Na2SiO3) were used to remove ions of cadmium from wastewater. Experiments were carried out in a batch process at room temperature (23 ± 1 ° C) for different operating parameters: adsorption time, pH value of solution, initial concentration of metal and mass of adsorbents. It was found that the optimum pH value for all adsorbents is above 6.0. The adsorption efficiency increases with increasing pH of the solution. With an increase in the initial concentration of cadmium, the adsorption capacity increases and reaches a value of over 200.0 mg/g. The experimental results have better agreement with Freundlich's adsorption isotherm (surface heterogeneity, hemisorption mechanism) and the pseudo-second order model (the principle of the chemisorption mechanism and adsorption rate depend on the adsorbent concentration). Alumosilicate geopolymer samples were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FTIR)., Za uklanjanje jona kadmijuma iz otpadnih voda korišćeni su alumosilikatni polimeri (geopolimeri) na bazi metakaolina kao prekursora i alkalni aktivator različitih koncentracija (2M, 4M, 6M i 8M NaOH/ Na2SiO3). Eksperimenti su vršeni u šaržnom procesu na sobnoj temperaturi (23±1 °C) pri različitim radnim parametrima: vreme adsorpcije, pH vrednost rastvora, početna koncentracija metala i masa adsorbenata. Utvrđeno je da je optimalna pH vrednost za sve adsorbente iznad 6,0. Efikasnost adsorpcije raste sa porastom pH vrednosti rastvora. Sa povećanjem početne koncentracije kadmijuma raste adsorpcioni kapacitet i dostiže vrednost preko 200,0 mg/g. Ekperimentalni rezultati su pokazali dobro slaganje sa Freundlich-ovom adsorpcionom izotermom i modelom pseudo-drugog reda. Karakterizacija geopolimera urađena je pomoću rendgenske difrakcije (XRD), skenirajuće elektronske mikroskopije (SEM) i infracrvene spektroskopije sa Furijeovom transformacijom (FTIR).",
publisher = "Savez inženjera i tehničara Srbije, Beograd",
journal = "Tehnika",
title = "Application of alumosilicate polymers based on metakaolin in adsorption of cadmium ions from wastewater, Primena alumosilikatnih polimera na bazi metakaolina u adsorpciji jona kadmijuma iz otpadnih voda",
pages = "756-749",
number = "6",
volume = "73",
doi = "10.5937/tehnika1806749M"
}

Mladenović, N. N., Ivanović, M. M., Kljajević, L. M., Nenadović, S. S., Gulicovski, J., Pavlović, V. P.,& Trivunac, K.. (2018). Application of alumosilicate polymers based on metakaolin in adsorption of cadmium ions from wastewater. in Tehnika
Savez inženjera i tehničara Srbije, Beograd., 73(6), 749-756.
https://doi.org/10.5937/tehnika1806749M

Mladenović NN, Ivanović MM, Kljajević LM, Nenadović SS, Gulicovski J, Pavlović VP, Trivunac K. Application of alumosilicate polymers based on metakaolin in adsorption of cadmium ions from wastewater. in Tehnika. 2018;73(6):749-756.
doi:10.5937/tehnika1806749M .

Mladenović, Nataša N., Ivanović, Marija M., Kljajević, Ljiljana M., Nenadović, Snežana S., Gulicovski, Jelena, Pavlović, Vera P., Trivunac, Katarina, "Application of alumosilicate polymers based on metakaolin in adsorption of cadmium ions from wastewater" in Tehnika, 73, no. 6 (2018):749-756,
https://doi.org/10.5937/tehnika1806749M . .

TY  - JOUR
AU  - Nenadović, Snežana S.
AU  - Kljajević, Ljiljana M.
AU  - Nešić, Maja A.
AU  - Petković, Marijana
AU  - Trivunac, Katarina
AU  - Pavlović, Vladimir B.
PY  - 2017
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3705
AB  - The paper presents chemical and structural analysis of geopolymer materials which are obtained by alkali-activated calcined clay (metakaolin) originated from Serbia under strictly defined conditions. Characterization of the metakaolin and geopolymers molecular structure has been done using X-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The paper presents the possibility of obtaining geopolymer structure and differences in chemical and structural characterization of these materials taking into account the concentration of NaOH as a variable parameter. The results of MALDI analysis of metakaolin and synthesized geopolymer structures using various matrix system: 2,4,6 trihydroxyacetophenone (THAP), alpha-cyano-4-hydroxycinnamic, 2,6 dihydroxyacetophenone and laser desorption/ionization, have shown that THAP matrix is the most appropriate for analysing these aluminosilicate materials.
PB  - Springer, New York
T2  - Environmental Earth Sciences
T1  - Structure analysis of geopolymers synthesized from clay originated from Serbia
IS  - 2
VL  - 76
DO  - 10.1007/s12665-016-6360-4
ER  - 

@article{
author = "Nenadović, Snežana S. and Kljajević, Ljiljana M. and Nešić, Maja A. and Petković, Marijana and Trivunac, Katarina and Pavlović, Vladimir B.",
year = "2017",
abstract = "The paper presents chemical and structural analysis of geopolymer materials which are obtained by alkali-activated calcined clay (metakaolin) originated from Serbia under strictly defined conditions. Characterization of the metakaolin and geopolymers molecular structure has been done using X-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The paper presents the possibility of obtaining geopolymer structure and differences in chemical and structural characterization of these materials taking into account the concentration of NaOH as a variable parameter. The results of MALDI analysis of metakaolin and synthesized geopolymer structures using various matrix system: 2,4,6 trihydroxyacetophenone (THAP), alpha-cyano-4-hydroxycinnamic, 2,6 dihydroxyacetophenone and laser desorption/ionization, have shown that THAP matrix is the most appropriate for analysing these aluminosilicate materials.",
publisher = "Springer, New York",
journal = "Environmental Earth Sciences",
title = "Structure analysis of geopolymers synthesized from clay originated from Serbia",
number = "2",
volume = "76",
doi = "10.1007/s12665-016-6360-4"
}

Nenadović, S. S., Kljajević, L. M., Nešić, M. A., Petković, M., Trivunac, K.,& Pavlović, V. B.. (2017). Structure analysis of geopolymers synthesized from clay originated from Serbia. in Environmental Earth Sciences
Springer, New York., 76(2).
https://doi.org/10.1007/s12665-016-6360-4

Nenadović SS, Kljajević LM, Nešić MA, Petković M, Trivunac K, Pavlović VB. Structure analysis of geopolymers synthesized from clay originated from Serbia. in Environmental Earth Sciences. 2017;76(2).
doi:10.1007/s12665-016-6360-4 .

Nenadović, Snežana S., Kljajević, Ljiljana M., Nešić, Maja A., Petković, Marijana, Trivunac, Katarina, Pavlović, Vladimir B., "Structure analysis of geopolymers synthesized from clay originated from Serbia" in Environmental Earth Sciences, 76, no. 2 (2017),
https://doi.org/10.1007/s12665-016-6360-4 . .

TY  - JOUR
AU  - Trivunac, Katarina
AU  - Kljajević, Ljiljana M.
AU  - Nenadović, Snežana S.
AU  - Gulicovski, Jelena
AU  - Mirković, Miljana M.
AU  - Babić, Biljana M.
AU  - Stevanović, Slavica
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3340
AB  - The microstructural characterization and adsorption properties of metakaolin (MK) and alkali-activated metakaolin, known as geopolymer materials (GP) were investigated. The structure and properties of the metakaolin and obtained geopolymer were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Furthermore, based on the analysis of adsorption efficiency, microstructure and mineral structure, the difference between geopolymer and metakaolin on the performance of immobilizing heavy metals have been discussed. The kinetics of adsorption can be represented by pseudo-second order equation. The results of lead ions adsorption experiments were best fitted by Freundlich adsorption isotherm for both investigated adsorbents. The highest removal efficiencies of alkali-activated material based on metakaolin was found 97.5% at pH 4 and metakaolin removal efficiencies was found 92% at pH 5.5.
PB  - Međunarodni Institut za nauku o sinterovanju, Beograd
T2  - Science of Sintering
T1  - Microstructural Characterization and Adsorption Properties of Alkali-Activated Materials Based on Metakaolin
EP  - 220
IS  - 2
SP  - 209
VL  - 48
DO  - 10.2298/SOS1602209T
ER  - 

@article{
author = "Trivunac, Katarina and Kljajević, Ljiljana M. and Nenadović, Snežana S. and Gulicovski, Jelena and Mirković, Miljana M. and Babić, Biljana M. and Stevanović, Slavica",
year = "2016",
abstract = "The microstructural characterization and adsorption properties of metakaolin (MK) and alkali-activated metakaolin, known as geopolymer materials (GP) were investigated. The structure and properties of the metakaolin and obtained geopolymer were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Furthermore, based on the analysis of adsorption efficiency, microstructure and mineral structure, the difference between geopolymer and metakaolin on the performance of immobilizing heavy metals have been discussed. The kinetics of adsorption can be represented by pseudo-second order equation. The results of lead ions adsorption experiments were best fitted by Freundlich adsorption isotherm for both investigated adsorbents. The highest removal efficiencies of alkali-activated material based on metakaolin was found 97.5% at pH 4 and metakaolin removal efficiencies was found 92% at pH 5.5.",
publisher = "Međunarodni Institut za nauku o sinterovanju, Beograd",
journal = "Science of Sintering",
title = "Microstructural Characterization and Adsorption Properties of Alkali-Activated Materials Based on Metakaolin",
pages = "220-209",
number = "2",
volume = "48",
doi = "10.2298/SOS1602209T"
}

Trivunac, K., Kljajević, L. M., Nenadović, S. S., Gulicovski, J., Mirković, M. M., Babić, B. M.,& Stevanović, S.. (2016). Microstructural Characterization and Adsorption Properties of Alkali-Activated Materials Based on Metakaolin. in Science of Sintering
Međunarodni Institut za nauku o sinterovanju, Beograd., 48(2), 209-220.
https://doi.org/10.2298/SOS1602209T

Trivunac K, Kljajević LM, Nenadović SS, Gulicovski J, Mirković MM, Babić BM, Stevanović S. Microstructural Characterization and Adsorption Properties of Alkali-Activated Materials Based on Metakaolin. in Science of Sintering. 2016;48(2):209-220.
doi:10.2298/SOS1602209T .

Trivunac, Katarina, Kljajević, Ljiljana M., Nenadović, Snežana S., Gulicovski, Jelena, Mirković, Miljana M., Babić, Biljana M., Stevanović, Slavica, "Microstructural Characterization and Adsorption Properties of Alkali-Activated Materials Based on Metakaolin" in Science of Sintering, 48, no. 2 (2016):209-220,
https://doi.org/10.2298/SOS1602209T . .

TY  - JOUR
AU  - Kljajević, Ljiljana M.
AU  - Nenadović, Snežana S.
AU  - Nenadović, Miloš
AU  - Gautam, Devendraprakash
AU  - Volkov-Husović, Tatjana
AU  - Devečerski, Aleksandar
AU  - Matović, Branko
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2530
AB  - Spark plasma sintering (SPS) of ZrC-SiC composite powders in the presence of LiYO2 sintering additive was studied. The starting powders were obtained by a carbothermal reduction (CTR) of natural mineral zircon (ZrSiO4), which provided an intimate mixing of in-situ created ZrC and SiC powders. This composite powder and LiYO2 as additive were densified by spark plasma sintering. Microstructural features of the composite were investigated by XRD, SEM/EDS and AFM analysis. The sintered composite material possesses promising mechanical properties and excellent cavitation resistance which was observed with a cavitation erosion test. The values of Vickers microhardness and fracture toughness of the composite material are 20.7 GPa and 5.07 MPam(1/2), respectively.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Spark plasma sintering of ZrC-SiC ceramics with LiYO2 additive
EP  - 5476
IS  - 5
SP  - 5467
VL  - 39
DO  - 10.1016/j.ceramint.2012.12.058
ER  - 

@article{
author = "Kljajević, Ljiljana M. and Nenadović, Snežana S. and Nenadović, Miloš and Gautam, Devendraprakash and Volkov-Husović, Tatjana and Devečerski, Aleksandar and Matović, Branko",
year = "2013",
abstract = "Spark plasma sintering (SPS) of ZrC-SiC composite powders in the presence of LiYO2 sintering additive was studied. The starting powders were obtained by a carbothermal reduction (CTR) of natural mineral zircon (ZrSiO4), which provided an intimate mixing of in-situ created ZrC and SiC powders. This composite powder and LiYO2 as additive were densified by spark plasma sintering. Microstructural features of the composite were investigated by XRD, SEM/EDS and AFM analysis. The sintered composite material possesses promising mechanical properties and excellent cavitation resistance which was observed with a cavitation erosion test. The values of Vickers microhardness and fracture toughness of the composite material are 20.7 GPa and 5.07 MPam(1/2), respectively.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Spark plasma sintering of ZrC-SiC ceramics with LiYO2 additive",
pages = "5476-5467",
number = "5",
volume = "39",
doi = "10.1016/j.ceramint.2012.12.058"
}

Kljajević, L. M., Nenadović, S. S., Nenadović, M., Gautam, D., Volkov-Husović, T., Devečerski, A.,& Matović, B.. (2013). Spark plasma sintering of ZrC-SiC ceramics with LiYO2 additive. in Ceramics International
Elsevier Sci Ltd, Oxford., 39(5), 5467-5476.
https://doi.org/10.1016/j.ceramint.2012.12.058

Kljajević LM, Nenadović SS, Nenadović M, Gautam D, Volkov-Husović T, Devečerski A, Matović B. Spark plasma sintering of ZrC-SiC ceramics with LiYO2 additive. in Ceramics International. 2013;39(5):5467-5476.
doi:10.1016/j.ceramint.2012.12.058 .

Kljajević, Ljiljana M., Nenadović, Snežana S., Nenadović, Miloš, Gautam, Devendraprakash, Volkov-Husović, Tatjana, Devečerski, Aleksandar, Matović, Branko, "Spark plasma sintering of ZrC-SiC ceramics with LiYO2 additive" in Ceramics International, 39, no. 5 (2013):5467-5476,
https://doi.org/10.1016/j.ceramint.2012.12.058 . .