TY  - JOUR
AU  - Jovanović, Jelena
AU  - Adnadjević, Borivoj
AU  - Kostić, Aleksandar
PY  - 2010
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/2407
AB  - The isothermal kinetics curves of the swelling of a poly(acrylic acid) hydrogel in buffer solutions of different pH values (5, 7, and 9) at temperatures ranging from 30 to 40 degrees C were determined. The possibilities of applying the Fick kinetics model and the Peppas equation were examined. It was found that the applicability of these models were limited. The kinetics model of a first-order chemical reaction was found to describe the swelling kinetics of the PAA hydrogel in all the investigated buffer solution at all the investigated temperatures. Swelling kinetics is determined by the rate of expansion of the network. The kinetic parameters (E(a), In A) of the swelling of the PAA hydrogel in buffer solutions of different pH values were determined. The activation energy and the pre-exponential factor of the swelling of the PAA hydrogel in buffer medium decreased with increasing pH value of the swelling medium.
PB  - John Wiley & Sons Inc, Hoboken
T2  - Journal of Applied Polymer Science
T1  - The Effects of the pH Value of the Swelling Medium on the Kinetics of the Swelling of a Poly(acrylic acid) Hydrogel
EP  - 1043
IS  - 2
SP  - 1036
VL  - 116
DO  - 10.1002/app.31501
ER  - 

@article{
author = "Jovanović, Jelena and Adnadjević, Borivoj and Kostić, Aleksandar",
year = "2010",
abstract = "The isothermal kinetics curves of the swelling of a poly(acrylic acid) hydrogel in buffer solutions of different pH values (5, 7, and 9) at temperatures ranging from 30 to 40 degrees C were determined. The possibilities of applying the Fick kinetics model and the Peppas equation were examined. It was found that the applicability of these models were limited. The kinetics model of a first-order chemical reaction was found to describe the swelling kinetics of the PAA hydrogel in all the investigated buffer solution at all the investigated temperatures. Swelling kinetics is determined by the rate of expansion of the network. The kinetic parameters (E(a), In A) of the swelling of the PAA hydrogel in buffer solutions of different pH values were determined. The activation energy and the pre-exponential factor of the swelling of the PAA hydrogel in buffer medium decreased with increasing pH value of the swelling medium.",
publisher = "John Wiley & Sons Inc, Hoboken",
journal = "Journal of Applied Polymer Science",
title = "The Effects of the pH Value of the Swelling Medium on the Kinetics of the Swelling of a Poly(acrylic acid) Hydrogel",
pages = "1043-1036",
number = "2",
volume = "116",
doi = "10.1002/app.31501"
}

Jovanović, J., Adnadjević, B.,& Kostić, A.. (2010). The Effects of the pH Value of the Swelling Medium on the Kinetics of the Swelling of a Poly(acrylic acid) Hydrogel. in Journal of Applied Polymer Science
John Wiley & Sons Inc, Hoboken., 116(2), 1036-1043.
https://doi.org/10.1002/app.31501

Jovanović J, Adnadjević B, Kostić A. The Effects of the pH Value of the Swelling Medium on the Kinetics of the Swelling of a Poly(acrylic acid) Hydrogel. in Journal of Applied Polymer Science. 2010;116(2):1036-1043.
doi:10.1002/app.31501 .

Jovanović, Jelena, Adnadjević, Borivoj, Kostić, Aleksandar, "The Effects of the pH Value of the Swelling Medium on the Kinetics of the Swelling of a Poly(acrylic acid) Hydrogel" in Journal of Applied Polymer Science, 116, no. 2 (2010):1036-1043,
https://doi.org/10.1002/app.31501 . .

TY  - CONF
AU  - Kostić, Aleksandar
AU  - Jovanović, J.
AU  - Adnadjević, Borivoj
AU  - Popović, A.
PY  - 2007
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/1573
AB  - Isothermal kinetics of copper (ion) binding to poly(acrylic acid) (PAA) hydrogel at 20, 25, 35 and 45 C was investigated. Isothermal conversions and kinetic curves of Cu2+ binding to the PAA hydrogel were determined. It was found that the well-known kinetic models of Peppas cannot be applied to describing the entire process of Cu2+ binding. The new method for the determination of the kinetic model of the Cu2+ binding process, as well as the activation energy density distribution functions of PAA hydrogel interaction with Cu2+, were established. It was found that Cu2+ diffusion to the active centers (with E-a = 9 kJ/mol) has a dominant influence on the kinetics of the process at temperatures T >= 30 degrees C, but at T >= 30 degrees C and for the degree of bound Cu2+ alpha >= 0.2, the interaction of Cu2+ from the adsorption center with E-a = 26 kJ/mol is dominant.
PB  - Maik Nauka/Interperiodica/Springer, New York
C3  - Russian Journal of Physical Chemistry A
T1  - Kinetics of Cu2+ binding to the poly(acrylic acid) hydrogel
EP  - 1379
IS  - 9
SP  - 1374
VL  - 81
DO  - 10.1134/S0036024407090051
ER  - 

@conference{
author = "Kostić, Aleksandar and Jovanović, J. and Adnadjević, Borivoj and Popović, A.",
year = "2007",
abstract = "Isothermal kinetics of copper (ion) binding to poly(acrylic acid) (PAA) hydrogel at 20, 25, 35 and 45 C was investigated. Isothermal conversions and kinetic curves of Cu2+ binding to the PAA hydrogel were determined. It was found that the well-known kinetic models of Peppas cannot be applied to describing the entire process of Cu2+ binding. The new method for the determination of the kinetic model of the Cu2+ binding process, as well as the activation energy density distribution functions of PAA hydrogel interaction with Cu2+, were established. It was found that Cu2+ diffusion to the active centers (with E-a = 9 kJ/mol) has a dominant influence on the kinetics of the process at temperatures T >= 30 degrees C, but at T >= 30 degrees C and for the degree of bound Cu2+ alpha >= 0.2, the interaction of Cu2+ from the adsorption center with E-a = 26 kJ/mol is dominant.",
publisher = "Maik Nauka/Interperiodica/Springer, New York",
journal = "Russian Journal of Physical Chemistry A",
title = "Kinetics of Cu2+ binding to the poly(acrylic acid) hydrogel",
pages = "1379-1374",
number = "9",
volume = "81",
doi = "10.1134/S0036024407090051"
}

Kostić, A., Jovanović, J., Adnadjević, B.,& Popović, A.. (2007). Kinetics of Cu2+ binding to the poly(acrylic acid) hydrogel. in Russian Journal of Physical Chemistry A
Maik Nauka/Interperiodica/Springer, New York., 81(9), 1374-1379.
https://doi.org/10.1134/S0036024407090051

Kostić A, Jovanović J, Adnadjević B, Popović A. Kinetics of Cu2+ binding to the poly(acrylic acid) hydrogel. in Russian Journal of Physical Chemistry A. 2007;81(9):1374-1379.
doi:10.1134/S0036024407090051 .

Kostić, Aleksandar, Jovanović, J., Adnadjević, Borivoj, Popović, A., "Kinetics of Cu2+ binding to the poly(acrylic acid) hydrogel" in Russian Journal of Physical Chemistry A, 81, no. 9 (2007):1374-1379,
https://doi.org/10.1134/S0036024407090051 . .

TY  - JOUR
AU  - Kostić, Aleksandar
AU  - Adnadjević, Borivoj
AU  - Popović, Aleksandar
AU  - Jovanović, Jelena
PY  - 2007
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/1570
AB  - The isothermal kinetics curves of the swelling of a poly(acrylic acid) hydrogel in distilled water and physiological solution at temperatures ranging from 20 to 40 ºC were determined. The possibility of applying both the Fick’s kinetics model and kinetics model of the first order chemical reaction to the swelling kinetics of the PAA hydrogel in distilled water and physiological solution were examined. It was found that the possibilities of applying these models were limited. The new model of the kinetics of swelling in distilled water and physiological solution was established. The kinetic parameters (Ea, ln A) for the swelling in distilled water and physiological solution were determined. The decrease of the equilibrium degree of swelling and the saturation swelling rate of the swelling of the PAA hydrogel in physiological solution compared to swelling in distilled water could be explained by the decreased differences in the ionic osmotic pressures between the hydrogel and the swelling medium. The increase of the initial swelling rate in the physiological solution might be caused by an increased density of charges at the network and by an increased affinity of the network towards the water molecules. The increase of the activation energy of the swelling of the PAA hydrogel in the physiological solution is a consequence of its additional "ionic crosslinking".
AB  - U radu su ispitivane izotermalne kinetičke krive bubrenja hidrogela delimično neutralisane poli(akrilne) kiseline u destilovanoj vodi i fiziološkom rastvoru u temperaturnom opsegu od 20 do 40 °C. Ispitivana je mogućnost primene Fikovog kinetičkog modela kao i kinetike i reda hemijskih reakcija na kinetiku bubrenja poliakrilnog hidrogela.Utvrđeno je da su mogućnosti za njihovu primenu vrlo ograničene. Iz tih razloga primenjen je novi model kinetike bubrenja. Određeni su kinetički parametri (Ea, lnA) za procese bubrenja u destilovanoj vodi i fiziološkom rastvoru. Smanjenje ravnotežnog stepena bubrenja i saturacione brzine bubrenja hidrogela delimično neutralisane poli(akrilne) kiseline u fiziološkom rastvoru u odnosu na destilovanu vodu može se objasniti smanjenjem razlike u jonskom osmotskom pritisku između hidrogela i medijuma za bubrenje. Povećanje inicijalne brzine bubrenja u fiziološkom rastvoru u odnosu na destilovanu vodu prouzrokovano je povećanjem gustine naelektrisanja na polimernoj mreži i povećanim afinitetom prema molekulima vode. Povećanje energije aktivacije hidrogela delimično neutralisane poli(akrilne) kiseline pri bubrenju u fiziološkom rastvoru se objašnjava dodatnim "jonskim umreženjem" hidrogela u fiziološkom rastvoru.
PB  - Srpsko hemijsko društvo, Beograd
T2  - JOURNAL OF THE SERBIAN CHEMICAL SOCIETY
T1  - Comparison of the swelling kinetics of a partially neutralized poly(acrylic acid) hydrogel in distilled water and physiological solution
T1  - Poređenje kinetike bubrenja hidrogela delimično neutralisane poli(akrilne) kiseline u destilovanoj vodi i fiziološkom rastvoru
EP  - 1153
IS  - 11
SP  - 1139
VL  - 72
DO  - 10.2298/JSC0711139K
ER  - 

@article{
author = "Kostić, Aleksandar and Adnadjević, Borivoj and Popović, Aleksandar and Jovanović, Jelena",
year = "2007",
abstract = "The isothermal kinetics curves of the swelling of a poly(acrylic acid) hydrogel in distilled water and physiological solution at temperatures ranging from 20 to 40 ºC were determined. The possibility of applying both the Fick’s kinetics model and kinetics model of the first order chemical reaction to the swelling kinetics of the PAA hydrogel in distilled water and physiological solution were examined. It was found that the possibilities of applying these models were limited. The new model of the kinetics of swelling in distilled water and physiological solution was established. The kinetic parameters (Ea, ln A) for the swelling in distilled water and physiological solution were determined. The decrease of the equilibrium degree of swelling and the saturation swelling rate of the swelling of the PAA hydrogel in physiological solution compared to swelling in distilled water could be explained by the decreased differences in the ionic osmotic pressures between the hydrogel and the swelling medium. The increase of the initial swelling rate in the physiological solution might be caused by an increased density of charges at the network and by an increased affinity of the network towards the water molecules. The increase of the activation energy of the swelling of the PAA hydrogel in the physiological solution is a consequence of its additional "ionic crosslinking"., U radu su ispitivane izotermalne kinetičke krive bubrenja hidrogela delimično neutralisane poli(akrilne) kiseline u destilovanoj vodi i fiziološkom rastvoru u temperaturnom opsegu od 20 do 40 °C. Ispitivana je mogućnost primene Fikovog kinetičkog modela kao i kinetike i reda hemijskih reakcija na kinetiku bubrenja poliakrilnog hidrogela.Utvrđeno je da su mogućnosti za njihovu primenu vrlo ograničene. Iz tih razloga primenjen je novi model kinetike bubrenja. Određeni su kinetički parametri (Ea, lnA) za procese bubrenja u destilovanoj vodi i fiziološkom rastvoru. Smanjenje ravnotežnog stepena bubrenja i saturacione brzine bubrenja hidrogela delimično neutralisane poli(akrilne) kiseline u fiziološkom rastvoru u odnosu na destilovanu vodu može se objasniti smanjenjem razlike u jonskom osmotskom pritisku između hidrogela i medijuma za bubrenje. Povećanje inicijalne brzine bubrenja u fiziološkom rastvoru u odnosu na destilovanu vodu prouzrokovano je povećanjem gustine naelektrisanja na polimernoj mreži i povećanim afinitetom prema molekulima vode. Povećanje energije aktivacije hidrogela delimično neutralisane poli(akrilne) kiseline pri bubrenju u fiziološkom rastvoru se objašnjava dodatnim "jonskim umreženjem" hidrogela u fiziološkom rastvoru.",
publisher = "Srpsko hemijsko društvo, Beograd",
journal = "JOURNAL OF THE SERBIAN CHEMICAL SOCIETY",
title = "Comparison of the swelling kinetics of a partially neutralized poly(acrylic acid) hydrogel in distilled water and physiological solution, Poređenje kinetike bubrenja hidrogela delimično neutralisane poli(akrilne) kiseline u destilovanoj vodi i fiziološkom rastvoru",
pages = "1153-1139",
number = "11",
volume = "72",
doi = "10.2298/JSC0711139K"
}

Kostić, A., Adnadjević, B., Popović, A.,& Jovanović, J.. (2007). Comparison of the swelling kinetics of a partially neutralized poly(acrylic acid) hydrogel in distilled water and physiological solution. in JOURNAL OF THE SERBIAN CHEMICAL SOCIETY
Srpsko hemijsko društvo, Beograd., 72(11), 1139-1153.
https://doi.org/10.2298/JSC0711139K

Kostić A, Adnadjević B, Popović A, Jovanović J. Comparison of the swelling kinetics of a partially neutralized poly(acrylic acid) hydrogel in distilled water and physiological solution. in JOURNAL OF THE SERBIAN CHEMICAL SOCIETY. 2007;72(11):1139-1153.
doi:10.2298/JSC0711139K .

Kostić, Aleksandar, Adnadjević, Borivoj, Popović, Aleksandar, Jovanović, Jelena, "Comparison of the swelling kinetics of a partially neutralized poly(acrylic acid) hydrogel in distilled water and physiological solution" in JOURNAL OF THE SERBIAN CHEMICAL SOCIETY, 72, no. 11 (2007):1139-1153,
https://doi.org/10.2298/JSC0711139K . .

TY  - JOUR
AU  - Petrović, S.
AU  - Rakić, Vesna
AU  - Jovanović, D.M.
AU  - Baricević, A.T.
PY  - 2006
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/1343
AB  - Perovskite type catalysts La0.7Sr0.3Cr1-xRuxO3 (0.025  lt = x  lt = 0.100) were synthesized by annealing a mixture of metal oxides and carbonates gradually up to 1000 degrees C in air, and characterized by XRPD, XPS, TPD, SEM-EDS and the van der Pauw method. The CO oxidation activity was investigated in a differential recycle reactor. According to the XRPD results, all samples achieved a perovskite structure, with a small presence of SrCrO4 phase. The XPS results revealed that the surface composition of all samples differed considerably from the stoichiometric value with ail important segregation of strontium and mainly ruthenium with regard to chromium at the surface of the catalysts. The sharp decrease of resistivity with increasing surface concentration of ruthenium and the independence of the resistivity on temperature for the sample with x = 0.100 imply the possible presence of SrRuO3, La-Ru-O and highly dispersed RuO2 (invisible by XRPD), known as good electric conductors, at the surface. The CO oxidation activity increases with increasing the degree of substitution (x). The surface concentrations of ruthenium are almost the same in the samples with x = 0.075 and 0.100. Those samples showed the similar values of resistivity in whole investigated temperature ram,e and very close CO oxidation activity. which indicates that the concentration of Ru4+ in the surface region and its stability are determining factors for the CO oxidation activity. The main results of this study are that ruthenium perovskites have a high thermal stability and CO oxidation activity.
PB  - Elsevier Science Bv, Amsterdam
T2  - Applied Catalysis B-Environmental
T1  - Oxidation of CO over Ru containing perovskite type oxides
EP  - 257
IS  - 3-4
SP  - 249
VL  - 66
DO  - 10.1016/j.apcatb.2006.04.003
ER  - 

@article{
author = "Petrović, S. and Rakić, Vesna and Jovanović, D.M. and Baricević, A.T.",
year = "2006",
abstract = "Perovskite type catalysts La0.7Sr0.3Cr1-xRuxO3 (0.025  lt = x  lt = 0.100) were synthesized by annealing a mixture of metal oxides and carbonates gradually up to 1000 degrees C in air, and characterized by XRPD, XPS, TPD, SEM-EDS and the van der Pauw method. The CO oxidation activity was investigated in a differential recycle reactor. According to the XRPD results, all samples achieved a perovskite structure, with a small presence of SrCrO4 phase. The XPS results revealed that the surface composition of all samples differed considerably from the stoichiometric value with ail important segregation of strontium and mainly ruthenium with regard to chromium at the surface of the catalysts. The sharp decrease of resistivity with increasing surface concentration of ruthenium and the independence of the resistivity on temperature for the sample with x = 0.100 imply the possible presence of SrRuO3, La-Ru-O and highly dispersed RuO2 (invisible by XRPD), known as good electric conductors, at the surface. The CO oxidation activity increases with increasing the degree of substitution (x). The surface concentrations of ruthenium are almost the same in the samples with x = 0.075 and 0.100. Those samples showed the similar values of resistivity in whole investigated temperature ram,e and very close CO oxidation activity. which indicates that the concentration of Ru4+ in the surface region and its stability are determining factors for the CO oxidation activity. The main results of this study are that ruthenium perovskites have a high thermal stability and CO oxidation activity.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Applied Catalysis B-Environmental",
title = "Oxidation of CO over Ru containing perovskite type oxides",
pages = "257-249",
number = "3-4",
volume = "66",
doi = "10.1016/j.apcatb.2006.04.003"
}

Petrović, S., Rakić, V., Jovanović, D.M.,& Baricević, A.T.. (2006). Oxidation of CO over Ru containing perovskite type oxides. in Applied Catalysis B-Environmental
Elsevier Science Bv, Amsterdam., 66(3-4), 249-257.
https://doi.org/10.1016/j.apcatb.2006.04.003

Petrović S, Rakić V, Jovanović D, Baricević A. Oxidation of CO over Ru containing perovskite type oxides. in Applied Catalysis B-Environmental. 2006;66(3-4):249-257.
doi:10.1016/j.apcatb.2006.04.003 .

Petrović, S., Rakić, Vesna, Jovanović, D.M., Baricević, A.T., "Oxidation of CO over Ru containing perovskite type oxides" in Applied Catalysis B-Environmental, 66, no. 3-4 (2006):249-257,
https://doi.org/10.1016/j.apcatb.2006.04.003 . .