TY  - JOUR
AU  - Đorđević, Nataša
AU  - Vlahović, M.
AU  - Mihajlović, Slavica
AU  - Martinović, S.
AU  - Vušović, Nenad M.
AU  - Šajić, J.L.
PY  - 2022
UR  - https://ritnms.itnms.ac.rs/handle/123456789/623
AB  - During mechanical activation, qualitative changes that can produce various phenomena occur in the material. In this study, anhydrous sodium carbonate was mechanically activated for 2, 7, 14, and 28 minutes in a vibro mill at a frequency of 3000 oscillations per minute. After activation, four series of activated samples were stored in the air at room conditions for 31 days (relaxation period). To monitor the kinetics of the transformation process of activated sodium carbonate samples, i.e. the mechanism of sodium bicarbonate formation during relaxation, Fourier-transform infrared (FTIR) spectroscopy analysis was used. FTIR testing was performed as a function of relaxation time for all four series of samples, with characteristic groups observed: CO32-, HCO3- and OH-. The obtained results provided kinetics parameters for the transformation of sodium carbonate into sodium bicarbonate due to the chemisorption of moisture and carbon dioxide from the atmosphere.
PB  - Međunarodni Institut za nauku o sinterovanju, Beograd
T2  - Science of Sintering
T1  - Fourier-Transform Infrared Spectroscopy Analysis of Mechanochemical Transformation Kinetics of Sodium Carbonate to Bicarbonate
EP  - 494
IS  - 4
SP  - 481
VL  - 54
DO  - 10.2298/SOS2204481D
UR  - conv_1000
ER  - 

@article{
author = "Đorđević, Nataša and Vlahović, M. and Mihajlović, Slavica and Martinović, S. and Vušović, Nenad M. and Šajić, J.L.",
year = "2022",
abstract = "During mechanical activation, qualitative changes that can produce various phenomena occur in the material. In this study, anhydrous sodium carbonate was mechanically activated for 2, 7, 14, and 28 minutes in a vibro mill at a frequency of 3000 oscillations per minute. After activation, four series of activated samples were stored in the air at room conditions for 31 days (relaxation period). To monitor the kinetics of the transformation process of activated sodium carbonate samples, i.e. the mechanism of sodium bicarbonate formation during relaxation, Fourier-transform infrared (FTIR) spectroscopy analysis was used. FTIR testing was performed as a function of relaxation time for all four series of samples, with characteristic groups observed: CO32-, HCO3- and OH-. The obtained results provided kinetics parameters for the transformation of sodium carbonate into sodium bicarbonate due to the chemisorption of moisture and carbon dioxide from the atmosphere.",
publisher = "Međunarodni Institut za nauku o sinterovanju, Beograd",
journal = "Science of Sintering",
title = "Fourier-Transform Infrared Spectroscopy Analysis of Mechanochemical Transformation Kinetics of Sodium Carbonate to Bicarbonate",
pages = "494-481",
number = "4",
volume = "54",
doi = "10.2298/SOS2204481D",
url = "conv_1000"
}

Đorđević, N., Vlahović, M., Mihajlović, S., Martinović, S., Vušović, N. M.,& Šajić, J.L.. (2022). Fourier-Transform Infrared Spectroscopy Analysis of Mechanochemical Transformation Kinetics of Sodium Carbonate to Bicarbonate. in Science of Sintering
Međunarodni Institut za nauku o sinterovanju, Beograd., 54(4), 481-494.
https://doi.org/10.2298/SOS2204481D
conv_1000

Đorđević N, Vlahović M, Mihajlović S, Martinović S, Vušović NM, Šajić J. Fourier-Transform Infrared Spectroscopy Analysis of Mechanochemical Transformation Kinetics of Sodium Carbonate to Bicarbonate. in Science of Sintering. 2022;54(4):481-494.
doi:10.2298/SOS2204481D
conv_1000 .

Đorđević, Nataša, Vlahović, M., Mihajlović, Slavica, Martinović, S., Vušović, Nenad M., Šajić, J.L., "Fourier-Transform Infrared Spectroscopy Analysis of Mechanochemical Transformation Kinetics of Sodium Carbonate to Bicarbonate" in Science of Sintering, 54, no. 4 (2022):481-494,
https://doi.org/10.2298/SOS2204481D .,
conv_1000 .

TY  - JOUR
AU  - Đorđević, Nataša
AU  - Martinović, S.
AU  - Vlahović, M.
AU  - Jovanić, P.
AU  - Vidojković, Velislav M.
AU  - Boljanac, Tamara
PY  - 2009
UR  - https://ritnms.itnms.ac.rs/handle/123456789/158
AB  - Sinterovanjem sistema 2MgO·2Al2O3·5SiO2, dobija se kordijerit, koji zbog svojih svojstava predstavlja izuzetno atraktivan keramički materijal. U cilju ispitivanja mogućnosti sniženja temperature formiranja kordijerita tokom procesa sinterovanja, izvršena su preliminarna ispitivanja mehanohemijske aktivacije stehiometrijske smeše polaznih komponenti. Efekti mehanohemijske aktivacije su praćeni termogravimetrijskom i diferencijalnom termijskom analizom. Specifična površina mehanički aktivirane smeše prahova je određivana BET i Coulter metodom. Kinetika povećanja specifične površine je analizirana tzv. Boltzmann-ovim modelom. Utvrđeno je da se sa povećanjem vremena aktivacije temperature na kojima se uočavaju fazne promene pomeraju ka nižim vrednostima. FFT IR analiza mehanohemijski aktiviranog praha nakon 24 meseci je pokazala da nije došlo do bitnih promena tokom 'starenja' materijala. Na osnovu dobijenih rezultata može se zaključiti da je mehanohemijska aktivacija imala uticaja na tretiranu praškastu smešu, pa se očekuje da se ovaj uticaj odrazi i na sniženje temperature formiranja kordijerita tokom procesa sinterovanja.
AB  - During sintering of the 2MgO-2Al2O3-5SiO2 system, cordierite, an attractive ceramic material because of its properties, is obtained. Effects of mechanochemical activation of stoichiometric mixtures, performed to investigate possibilities of lowering cordierite formation temperature during sintering, were monitored by thermogravimetric and differential thermal analyses. Specific surface areas of the mechanically activated powder mixtures were determined by the BET method. Kinetics of the specific surface area increase was analyzed using the Boltzmann model. It was confirmed that with activation time increase, temperatures of phase transformations were shifted to lower values and, according to FTIR analysis no significant changes occurred during material aging. According to the obtained results, it may be concluded that since mechanochemical activation has an influence on the treated powder mixture, lowering of the cordierite formation temperature during the sintering process is expected.
PB  - Međunarodni Institut za nauku o sinterovanju, Beograd
T2  - Science of Sintering
T1  - Kinetics of specific surface area change using the Boltzmann model
EP  - 274
IS  - 3
SP  - 267
VL  - 41
DO  - 10.2298/SOS0903267D
UR  - conv_579
ER  - 

@article{
author = "Đorđević, Nataša and Martinović, S. and Vlahović, M. and Jovanić, P. and Vidojković, Velislav M. and Boljanac, Tamara",
year = "2009",
abstract = "Sinterovanjem sistema 2MgO·2Al2O3·5SiO2, dobija se kordijerit, koji zbog svojih svojstava predstavlja izuzetno atraktivan keramički materijal. U cilju ispitivanja mogućnosti sniženja temperature formiranja kordijerita tokom procesa sinterovanja, izvršena su preliminarna ispitivanja mehanohemijske aktivacije stehiometrijske smeše polaznih komponenti. Efekti mehanohemijske aktivacije su praćeni termogravimetrijskom i diferencijalnom termijskom analizom. Specifična površina mehanički aktivirane smeše prahova je određivana BET i Coulter metodom. Kinetika povećanja specifične površine je analizirana tzv. Boltzmann-ovim modelom. Utvrđeno je da se sa povećanjem vremena aktivacije temperature na kojima se uočavaju fazne promene pomeraju ka nižim vrednostima. FFT IR analiza mehanohemijski aktiviranog praha nakon 24 meseci je pokazala da nije došlo do bitnih promena tokom 'starenja' materijala. Na osnovu dobijenih rezultata može se zaključiti da je mehanohemijska aktivacija imala uticaja na tretiranu praškastu smešu, pa se očekuje da se ovaj uticaj odrazi i na sniženje temperature formiranja kordijerita tokom procesa sinterovanja., During sintering of the 2MgO-2Al2O3-5SiO2 system, cordierite, an attractive ceramic material because of its properties, is obtained. Effects of mechanochemical activation of stoichiometric mixtures, performed to investigate possibilities of lowering cordierite formation temperature during sintering, were monitored by thermogravimetric and differential thermal analyses. Specific surface areas of the mechanically activated powder mixtures were determined by the BET method. Kinetics of the specific surface area increase was analyzed using the Boltzmann model. It was confirmed that with activation time increase, temperatures of phase transformations were shifted to lower values and, according to FTIR analysis no significant changes occurred during material aging. According to the obtained results, it may be concluded that since mechanochemical activation has an influence on the treated powder mixture, lowering of the cordierite formation temperature during the sintering process is expected.",
publisher = "Međunarodni Institut za nauku o sinterovanju, Beograd",
journal = "Science of Sintering",
title = "Kinetics of specific surface area change using the Boltzmann model",
pages = "274-267",
number = "3",
volume = "41",
doi = "10.2298/SOS0903267D",
url = "conv_579"
}

Đorđević, N., Martinović, S., Vlahović, M., Jovanić, P., Vidojković, V. M.,& Boljanac, T.. (2009). Kinetics of specific surface area change using the Boltzmann model. in Science of Sintering
Međunarodni Institut za nauku o sinterovanju, Beograd., 41(3), 267-274.
https://doi.org/10.2298/SOS0903267D
conv_579

Đorđević N, Martinović S, Vlahović M, Jovanić P, Vidojković VM, Boljanac T. Kinetics of specific surface area change using the Boltzmann model. in Science of Sintering. 2009;41(3):267-274.
doi:10.2298/SOS0903267D
conv_579 .

Đorđević, Nataša, Martinović, S., Vlahović, M., Jovanić, P., Vidojković, Velislav M., Boljanac, Tamara, "Kinetics of specific surface area change using the Boltzmann model" in Science of Sintering, 41, no. 3 (2009):267-274,
https://doi.org/10.2298/SOS0903267D .,
conv_579 .