TY  - JOUR
AU  - Panić, Vesna V.
AU  - Jovanović, Jelena D.
AU  - Spasojević, Jelena P.
AU  - Savić, Sanja I.
AU  - Marković, Maja D.
AU  - Radulović, Aleksandra M.
AU  - Adnađević, Borivoj K.
PY  - 2024
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7349
AB  - High concentrations of LTA zeolite (27-52mass%) were embedded in poly(methacrylic acid) (PMAA) matrix to obtain composite hydrogels with porosity and active sites originating from both components. Substandard mechanics of PMAA and aggregation of zeolite particles, were thereby overcome. The composites had remarkably higher density than PMAA xerogel (1700 to1400 kg m−3), higher crosslinking density (54.8 to1.29 mol m−3) and lower swelling degree (41 to 420 kg kg−1). Zeolite particles were uniformly dispersed in PMAA matrix and there was no agglomeration or leaching of zeolite despite very high concentrations. XRD patterns revealed that the inclusion of zeolite particles affected the short-range order in the PMAA matrix. Being an active filler LTA zeolite notably improved thermal stability and mechanics of PMAA hydrogel, multiplying the storage modulus 5.2 times in dry and 21.8 times in swollen state. Structure–property correlations were provided making the base for further development of tailor-made zeolite-PMAA composite hydrogels.
PB  - Elsevier
T2  - Chemical Engineering Science
T1  - Structure–property correlations for composite hydrogels based on poly(methacrylic acid) and high concentrations of LTA zeolite
SP  - 119981
VL  - 292
DO  - 10.1016/j.ces.2024.119981
ER  - 

@article{
author = "Panić, Vesna V. and Jovanović, Jelena D. and Spasojević, Jelena P. and Savić, Sanja I. and Marković, Maja D. and Radulović, Aleksandra M. and Adnađević, Borivoj K.",
year = "2024",
abstract = "High concentrations of LTA zeolite (27-52mass%) were embedded in poly(methacrylic acid) (PMAA) matrix to obtain composite hydrogels with porosity and active sites originating from both components. Substandard mechanics of PMAA and aggregation of zeolite particles, were thereby overcome. The composites had remarkably higher density than PMAA xerogel (1700 to1400 kg m−3), higher crosslinking density (54.8 to1.29 mol m−3) and lower swelling degree (41 to 420 kg kg−1). Zeolite particles were uniformly dispersed in PMAA matrix and there was no agglomeration or leaching of zeolite despite very high concentrations. XRD patterns revealed that the inclusion of zeolite particles affected the short-range order in the PMAA matrix. Being an active filler LTA zeolite notably improved thermal stability and mechanics of PMAA hydrogel, multiplying the storage modulus 5.2 times in dry and 21.8 times in swollen state. Structure–property correlations were provided making the base for further development of tailor-made zeolite-PMAA composite hydrogels.",
publisher = "Elsevier",
journal = "Chemical Engineering Science",
title = "Structure–property correlations for composite hydrogels based on poly(methacrylic acid) and high concentrations of LTA zeolite",
pages = "119981",
volume = "292",
doi = "10.1016/j.ces.2024.119981"
}

Panić, V. V., Jovanović, J. D., Spasojević, J. P., Savić, S. I., Marković, M. D., Radulović, A. M.,& Adnađević, B. K.. (2024). Structure–property correlations for composite hydrogels based on poly(methacrylic acid) and high concentrations of LTA zeolite. in Chemical Engineering Science
Elsevier., 292, 119981.
https://doi.org/10.1016/j.ces.2024.119981

Panić VV, Jovanović JD, Spasojević JP, Savić SI, Marković MD, Radulović AM, Adnađević BK. Structure–property correlations for composite hydrogels based on poly(methacrylic acid) and high concentrations of LTA zeolite. in Chemical Engineering Science. 2024;292:119981.
doi:10.1016/j.ces.2024.119981 .

Panić, Vesna V., Jovanović, Jelena D., Spasojević, Jelena P., Savić, Sanja I., Marković, Maja D., Radulović, Aleksandra M., Adnađević, Borivoj K., "Structure–property correlations for composite hydrogels based on poly(methacrylic acid) and high concentrations of LTA zeolite" in Chemical Engineering Science, 292 (2024):119981,
https://doi.org/10.1016/j.ces.2024.119981 . .

TY  - JOUR
AU  - Panić, Vesna V.
AU  - Jovanović, Jelena D.
AU  - Popović, Ivanka G.
AU  - Savić, Sanja I.
AU  - Marković, Maja D.
AU  - Spasojević, Pavle M.
AU  - Adnađević, Borivoj K.
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5966
AB  - High concentrations of hydrophobic MFI zeolite (26.0–51.3 wt%) were successfully embedded in poly(methacrylic acid) (PMAA) network in simple, one-pot synthesis of PMAA-MFI composite hydrogels. The effects of zeolite concentration regarding pure PMAA xerogel, for all of the investigated properties (primary structural parameters, morphological properties, water swelling ability, thermal degradation mechanism and stability, and mechanical properties) were determined and discussed. The PMAA-MFI composite hydrogels had remarkably higher density than PMAA xerogel (1660/1420 kg m−3), higher crosslinking density (29/1.0 × 10−4), improved mechanics in the dry and swollen state (up to 4.9 times higher storage modulus) and lower swelling degree (42/420 g g−1), average molar mass between the network crosslinks (3.6/110 × 104 g mol−1), and distance between the macromolecular chains (64/710 nm). Despite high zeolite concentration, the composites kept porous hydrogel structure with uniformly dispersed zeolite particles. FTIR spectra disclosed the existence of functional groups of PMAA network and MFI zeolite that interacted mutually and led to increased crosslinking density. The effect of zeolite concentration on the thermal degradation mechanism was established. The composition-properties correlations were determined and described by the adequate linear or power law equations revealing the additive nature of the composites and the fractal structure of the networks. These correlations enable the achievement of desired properties by simple adjustment of the initial composition, i.e. zeolite concentration. Therefore, this work presents the base for further development of tailor-made PMAA-MFI composite hydrogels aimed for specific application.
PB  - Elsevier
T2  - Polymer
T1  - The study of composition-properties relationships for composite hydrogels based on poly(methacrylic acid) and high concentrations of MFI zeolite
SP  - 125750
VL  - 269
DO  - 10.1016/j.polymer.2023.125750
ER  - 

@article{
author = "Panić, Vesna V. and Jovanović, Jelena D. and Popović, Ivanka G. and Savić, Sanja I. and Marković, Maja D. and Spasojević, Pavle M. and Adnađević, Borivoj K.",
year = "2023",
abstract = "High concentrations of hydrophobic MFI zeolite (26.0–51.3 wt%) were successfully embedded in poly(methacrylic acid) (PMAA) network in simple, one-pot synthesis of PMAA-MFI composite hydrogels. The effects of zeolite concentration regarding pure PMAA xerogel, for all of the investigated properties (primary structural parameters, morphological properties, water swelling ability, thermal degradation mechanism and stability, and mechanical properties) were determined and discussed. The PMAA-MFI composite hydrogels had remarkably higher density than PMAA xerogel (1660/1420 kg m−3), higher crosslinking density (29/1.0 × 10−4), improved mechanics in the dry and swollen state (up to 4.9 times higher storage modulus) and lower swelling degree (42/420 g g−1), average molar mass between the network crosslinks (3.6/110 × 104 g mol−1), and distance between the macromolecular chains (64/710 nm). Despite high zeolite concentration, the composites kept porous hydrogel structure with uniformly dispersed zeolite particles. FTIR spectra disclosed the existence of functional groups of PMAA network and MFI zeolite that interacted mutually and led to increased crosslinking density. The effect of zeolite concentration on the thermal degradation mechanism was established. The composition-properties correlations were determined and described by the adequate linear or power law equations revealing the additive nature of the composites and the fractal structure of the networks. These correlations enable the achievement of desired properties by simple adjustment of the initial composition, i.e. zeolite concentration. Therefore, this work presents the base for further development of tailor-made PMAA-MFI composite hydrogels aimed for specific application.",
publisher = "Elsevier",
journal = "Polymer",
title = "The study of composition-properties relationships for composite hydrogels based on poly(methacrylic acid) and high concentrations of MFI zeolite",
pages = "125750",
volume = "269",
doi = "10.1016/j.polymer.2023.125750"
}

Panić, V. V., Jovanović, J. D., Popović, I. G., Savić, S. I., Marković, M. D., Spasojević, P. M.,& Adnađević, B. K.. (2023). The study of composition-properties relationships for composite hydrogels based on poly(methacrylic acid) and high concentrations of MFI zeolite. in Polymer
Elsevier., 269, 125750.
https://doi.org/10.1016/j.polymer.2023.125750

Panić VV, Jovanović JD, Popović IG, Savić SI, Marković MD, Spasojević PM, Adnađević BK. The study of composition-properties relationships for composite hydrogels based on poly(methacrylic acid) and high concentrations of MFI zeolite. in Polymer. 2023;269:125750.
doi:10.1016/j.polymer.2023.125750 .

Panić, Vesna V., Jovanović, Jelena D., Popović, Ivanka G., Savić, Sanja I., Marković, Maja D., Spasojević, Pavle M., Adnađević, Borivoj K., "The study of composition-properties relationships for composite hydrogels based on poly(methacrylic acid) and high concentrations of MFI zeolite" in Polymer, 269 (2023):125750,
https://doi.org/10.1016/j.polymer.2023.125750 . .

TY  - CONF
AU  - Jovanović, Jelena D.
AU  - Panić, Vesna V.
AU  - Spasojević, Pavle M.
AU  - Popović, Ivanka G.
AU  - Adnađević, Borivoj K.
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6977
AB  - Composite hydrogels are the subject of intensive research due to there specific 3D cross-linked
structure with extraordinary physical and chemical properties which enables variety of applications In
spite of increasing interest for using different external fields in physical-chemical processes, three are
no available literature data about the effects of external fields on swelling and swelling kinetics of
hydrogels. Therefore, the effects of (conventional) thermal (TH), ultrasonic (US) and microwave (MW)
fields, on the swelling degree and swelling kinetics. A sample of poly(methacrylic acid) (PMAA) xerogel
with 10%wt of LTA-zeolite (PMMA-LTA) was synthesized and thoroughly characterized. The
isothermal kinetic swelling curves were determined within a temperature range T= 293-323K in the
TH, US and MW fields. The results were well fitted with the Peppas’ kinetic model. At all applied
fields, with an increase in temperature, there is an increase in the equilibrium swelling degree (SDeq)
and the swelling rate constant (k), while the parameter of Pepass's model (n) decreases. The maximum
value of SDeq and parameter n is achieved at TH, while the US assisted process leads to the maximum
value of k. The minimum value of the activation energy (Ea) and at the same time the maximum value
of the pre-exponential factor (lnA) lnA were achieved by applying the MW field. The influence of US
and MW fields on the diffusion of water molecules through the polymer network, activation of the
polymer network for swelling and relaxation of the polymer network was analysed.
PB  - Yuktan Technologies
C3  - Abstract Book / 4th International Conference on Advanced Polymer Science and Engineering, 23-25 October, 2023, Valencia, Spain
T1  - The Effects of Different Physical Fields on Swelling Kinetics of PMAA-LTA Zeolite Composite Hydrogel Under Controlled Isothermal Conditions
SP  - 63
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6977
ER  - 

@conference{
author = "Jovanović, Jelena D. and Panić, Vesna V. and Spasojević, Pavle M. and Popović, Ivanka G. and Adnađević, Borivoj K.",
year = "2023",
abstract = "Composite hydrogels are the subject of intensive research due to there specific 3D cross-linked
structure with extraordinary physical and chemical properties which enables variety of applications In
spite of increasing interest for using different external fields in physical-chemical processes, three are
no available literature data about the effects of external fields on swelling and swelling kinetics of
hydrogels. Therefore, the effects of (conventional) thermal (TH), ultrasonic (US) and microwave (MW)
fields, on the swelling degree and swelling kinetics. A sample of poly(methacrylic acid) (PMAA) xerogel
with 10%wt of LTA-zeolite (PMMA-LTA) was synthesized and thoroughly characterized. The
isothermal kinetic swelling curves were determined within a temperature range T= 293-323K in the
TH, US and MW fields. The results were well fitted with the Peppas’ kinetic model. At all applied
fields, with an increase in temperature, there is an increase in the equilibrium swelling degree (SDeq)
and the swelling rate constant (k), while the parameter of Pepass's model (n) decreases. The maximum
value of SDeq and parameter n is achieved at TH, while the US assisted process leads to the maximum
value of k. The minimum value of the activation energy (Ea) and at the same time the maximum value
of the pre-exponential factor (lnA) lnA were achieved by applying the MW field. The influence of US
and MW fields on the diffusion of water molecules through the polymer network, activation of the
polymer network for swelling and relaxation of the polymer network was analysed.",
publisher = "Yuktan Technologies",
journal = "Abstract Book / 4th International Conference on Advanced Polymer Science and Engineering, 23-25 October, 2023, Valencia, Spain",
title = "The Effects of Different Physical Fields on Swelling Kinetics of PMAA-LTA Zeolite Composite Hydrogel Under Controlled Isothermal Conditions",
pages = "63",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6977"
}

Jovanović, J. D., Panić, V. V., Spasojević, P. M., Popović, I. G.,& Adnađević, B. K.. (2023). The Effects of Different Physical Fields on Swelling Kinetics of PMAA-LTA Zeolite Composite Hydrogel Under Controlled Isothermal Conditions. in Abstract Book / 4th International Conference on Advanced Polymer Science and Engineering, 23-25 October, 2023, Valencia, Spain
Yuktan Technologies., 63.
https://hdl.handle.net/21.15107/rcub_technorep_6977

Jovanović JD, Panić VV, Spasojević PM, Popović IG, Adnađević BK. The Effects of Different Physical Fields on Swelling Kinetics of PMAA-LTA Zeolite Composite Hydrogel Under Controlled Isothermal Conditions. in Abstract Book / 4th International Conference on Advanced Polymer Science and Engineering, 23-25 October, 2023, Valencia, Spain. 2023;:63.
https://hdl.handle.net/21.15107/rcub_technorep_6977 .

Jovanović, Jelena D., Panić, Vesna V., Spasojević, Pavle M., Popović, Ivanka G., Adnađević, Borivoj K., "The Effects of Different Physical Fields on Swelling Kinetics of PMAA-LTA Zeolite Composite Hydrogel Under Controlled Isothermal Conditions" in Abstract Book / 4th International Conference on Advanced Polymer Science and Engineering, 23-25 October, 2023, Valencia, Spain (2023):63,
https://hdl.handle.net/21.15107/rcub_technorep_6977 .

TY  - CONF
AU  - Jovanović, Jelena
AU  - Panić, Vesna
AU  - Adnađević, Borivoj
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6976
AB  - Hydrogels are 3D cross-linked structures that, due to their unique physical and chemical properties and
possible applications, are the subject of intensive research in recent decades. In this work, the effects of
external physical fields (ultrasonic (US) and microwave (MW)) on the isothermal swelling kinetics of
poly(methacrylic acid) hydrogel were examined. A sample of poly(methacrylic acid) (PMAA) xerogel (PMMAX) was synthesized by the process of cross-linking free radical polymerization, which is described in detail in
the paper [1]. The basic primary structural properties of PMMA-X including the equilibrium swelling degree
in distilled water (SDeq), the density of xerogel (ρxg), the average molar mass between the crosslinks of a
network (Mc), the degree of crosslinking (ρc) and the distance between the macromolecular chains (ξ), were
determined and calculated. The isothermal kinetic swelling curves were determined by the tee-bag method at
a temperature range of T= 293-323K in the presence of thermal, ultrasonic, and microwave fields. The
isothermal kinetic curves of swelling were fitted with the Peppas’ kinetic model [2]. The values of the
isothermal kinetic parameters of the Peppas model (k, n) were calculated. Based on the temperature
dependence of the parameter using the Arrhenius equation, all values of the activation energy (Ea) and the
pre-exponential factor (lnA) of the swelling process in the presence of different physical fields were calculated.
The obtained results indicate that the presence of US and MW fields leads to an increase in the values of k, n,
Ea, and compared to the corresponding values during conventional heating. The US field relatively slightly
increases the value of SDeq, while the MW field significantly reduces the value of SDeq. The values of Ea and
lnA at different physical fields are interrelated by a correlation relationship (compensation effect) which is
given by the relation: lnAf=0.326+0.406Ea, f The existence of a compensation effect [3] is an indication of the
unique mechanism of activation of the polymer network at different physical fields for swelling and of the
quantum nature of Ea. The influence of US and MW fields on the diffusion of water molecules through the
polymer network, activation of the polymer network for swelling, and relaxation of the polymer network was
analyzed.
PB  - Niš : RAD Centre
C3  - Book of abstracts / Eleventh International Conference on Radiation, Natural Sciences, Medicine, Engineering, Technology and Ecology (RAD 2023), 19–23.06.2023, Herceg Novi
T1  - About the influence of different external fields on the swelling kinetics of PMAA hydrogels
SP  - 143
DO  - 10.21175/rad.abstr.book.2023.25.2
ER  - 

@conference{
author = "Jovanović, Jelena and Panić, Vesna and Adnađević, Borivoj",
year = "2023",
abstract = "Hydrogels are 3D cross-linked structures that, due to their unique physical and chemical properties and
possible applications, are the subject of intensive research in recent decades. In this work, the effects of
external physical fields (ultrasonic (US) and microwave (MW)) on the isothermal swelling kinetics of
poly(methacrylic acid) hydrogel were examined. A sample of poly(methacrylic acid) (PMAA) xerogel (PMMAX) was synthesized by the process of cross-linking free radical polymerization, which is described in detail in
the paper [1]. The basic primary structural properties of PMMA-X including the equilibrium swelling degree
in distilled water (SDeq), the density of xerogel (ρxg), the average molar mass between the crosslinks of a
network (Mc), the degree of crosslinking (ρc) and the distance between the macromolecular chains (ξ), were
determined and calculated. The isothermal kinetic swelling curves were determined by the tee-bag method at
a temperature range of T= 293-323K in the presence of thermal, ultrasonic, and microwave fields. The
isothermal kinetic curves of swelling were fitted with the Peppas’ kinetic model [2]. The values of the
isothermal kinetic parameters of the Peppas model (k, n) were calculated. Based on the temperature
dependence of the parameter using the Arrhenius equation, all values of the activation energy (Ea) and the
pre-exponential factor (lnA) of the swelling process in the presence of different physical fields were calculated.
The obtained results indicate that the presence of US and MW fields leads to an increase in the values of k, n,
Ea, and compared to the corresponding values during conventional heating. The US field relatively slightly
increases the value of SDeq, while the MW field significantly reduces the value of SDeq. The values of Ea and
lnA at different physical fields are interrelated by a correlation relationship (compensation effect) which is
given by the relation: lnAf=0.326+0.406Ea, f The existence of a compensation effect [3] is an indication of the
unique mechanism of activation of the polymer network at different physical fields for swelling and of the
quantum nature of Ea. The influence of US and MW fields on the diffusion of water molecules through the
polymer network, activation of the polymer network for swelling, and relaxation of the polymer network was
analyzed.",
publisher = "Niš : RAD Centre",
journal = "Book of abstracts / Eleventh International Conference on Radiation, Natural Sciences, Medicine, Engineering, Technology and Ecology (RAD 2023), 19–23.06.2023, Herceg Novi",
title = "About the influence of different external fields on the swelling kinetics of PMAA hydrogels",
pages = "143",
doi = "10.21175/rad.abstr.book.2023.25.2"
}

Jovanović, J., Panić, V.,& Adnađević, B.. (2023). About the influence of different external fields on the swelling kinetics of PMAA hydrogels. in Book of abstracts / Eleventh International Conference on Radiation, Natural Sciences, Medicine, Engineering, Technology and Ecology (RAD 2023), 19–23.06.2023, Herceg Novi
Niš : RAD Centre., 143.
https://doi.org/10.21175/rad.abstr.book.2023.25.2

Jovanović J, Panić V, Adnađević B. About the influence of different external fields on the swelling kinetics of PMAA hydrogels. in Book of abstracts / Eleventh International Conference on Radiation, Natural Sciences, Medicine, Engineering, Technology and Ecology (RAD 2023), 19–23.06.2023, Herceg Novi. 2023;:143.
doi:10.21175/rad.abstr.book.2023.25.2 .

Jovanović, Jelena, Panić, Vesna, Adnađević, Borivoj, "About the influence of different external fields on the swelling kinetics of PMAA hydrogels" in Book of abstracts / Eleventh International Conference on Radiation, Natural Sciences, Medicine, Engineering, Technology and Ecology (RAD 2023), 19–23.06.2023, Herceg Novi (2023):143,
https://doi.org/10.21175/rad.abstr.book.2023.25.2 . .

TY  - JOUR
AU  - Krstajić Pajić, Mila N.
AU  - Dobrota, Ana S.
AU  - Mazare, Anca
AU  - Đurđić, Slađana
AU  - Hwang, Imgon
AU  - Skorodumova, Natalia V.
AU  - Manojlović, Dragan
AU  - Vasilić, Rastko
AU  - Pašti, Igor A.
AU  - Schmuki, Patrik
AU  - Lačnjevac, Uroš
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6576
AB  - Efficient cathodes for the hydrogen evolution reaction (HER) in acidic water electrolysis rely on the use of expensive platinum group metals (PGMs). However, to achieve economically viable operation, both the content of PGMs must be reduced and their intrinsically strong H adsorption mitigated. Herein, we show that the surface effects of hydrogenated TiO2 nanotube (TNT) arrays can make osmium, a so far less-explored PGM, a highly active HER electrocatalyst. These defect-rich TiO2 nanostructures provide an interactive scaffold for the galvanic deposition of Os particles with modulated adsorption properties. Through systematic investigations, we identify the synthesis conditions (OsCl3 concentration/temperature/reaction time) that yield a progressive improvement in Os deposition rate and mass loading, thereby decreasing the HER overpotential. At the same time, the Os particles deposited by this procedure remain mainly sub-nanometric and entirely cover the inner tube walls. An optimally balanced Os@TNT composite prepared at 3 mM/55 °C/30 min exhibits a record low overpotential (η) of 61 mV at a current density of 100 mA cm-2, a high mass activity of 20.8 A mgOs-1 at 80 mV, and a stable performance in an acidic medium. Density functional theory calculations indicate the existence of strong interactions between the hydrogenated TiO2 surface and small Os clusters, which may weaken the Os-H* binding strength and thus boost the intrinsic HER activity of Os centers. The results presented in this study offer new directions for the fabrication of cost-effective PGM-based catalysts and a better understanding of the synergistic electronic interactions at the PGM|TiO2 interface.
PB  - American Chemical Society
T1  - Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance
EP  - 31469
IS  - 26
SP  - 31459
VL  - 15
DO  - 10.1021/acsami.3c04498
ER  - 

@article{
author = "Krstajić Pajić, Mila N. and Dobrota, Ana S. and Mazare, Anca and Đurđić, Slađana and Hwang, Imgon and Skorodumova, Natalia V. and Manojlović, Dragan and Vasilić, Rastko and Pašti, Igor A. and Schmuki, Patrik and Lačnjevac, Uroš",
year = "2023",
abstract = "Efficient cathodes for the hydrogen evolution reaction (HER) in acidic water electrolysis rely on the use of expensive platinum group metals (PGMs). However, to achieve economically viable operation, both the content of PGMs must be reduced and their intrinsically strong H adsorption mitigated. Herein, we show that the surface effects of hydrogenated TiO2 nanotube (TNT) arrays can make osmium, a so far less-explored PGM, a highly active HER electrocatalyst. These defect-rich TiO2 nanostructures provide an interactive scaffold for the galvanic deposition of Os particles with modulated adsorption properties. Through systematic investigations, we identify the synthesis conditions (OsCl3 concentration/temperature/reaction time) that yield a progressive improvement in Os deposition rate and mass loading, thereby decreasing the HER overpotential. At the same time, the Os particles deposited by this procedure remain mainly sub-nanometric and entirely cover the inner tube walls. An optimally balanced Os@TNT composite prepared at 3 mM/55 °C/30 min exhibits a record low overpotential (η) of 61 mV at a current density of 100 mA cm-2, a high mass activity of 20.8 A mgOs-1 at 80 mV, and a stable performance in an acidic medium. Density functional theory calculations indicate the existence of strong interactions between the hydrogenated TiO2 surface and small Os clusters, which may weaken the Os-H* binding strength and thus boost the intrinsic HER activity of Os centers. The results presented in this study offer new directions for the fabrication of cost-effective PGM-based catalysts and a better understanding of the synergistic electronic interactions at the PGM|TiO2 interface.",
publisher = "American Chemical Society",
title = "Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance",
pages = "31469-31459",
number = "26",
volume = "15",
doi = "10.1021/acsami.3c04498"
}

Krstajić Pajić, M. N., Dobrota, A. S., Mazare, A., Đurđić, S., Hwang, I., Skorodumova, N. V., Manojlović, D., Vasilić, R., Pašti, I. A., Schmuki, P.,& Lačnjevac, U.. (2023). Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance. 
American Chemical Society., 15(26), 31459-31469.
https://doi.org/10.1021/acsami.3c04498

Krstajić Pajić MN, Dobrota AS, Mazare A, Đurđić S, Hwang I, Skorodumova NV, Manojlović D, Vasilić R, Pašti IA, Schmuki P, Lačnjevac U. Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance. 2023;15(26):31459-31469.
doi:10.1021/acsami.3c04498 .

Krstajić Pajić, Mila N., Dobrota, Ana S., Mazare, Anca, Đurđić, Slađana, Hwang, Imgon, Skorodumova, Natalia V., Manojlović, Dragan, Vasilić, Rastko, Pašti, Igor A., Schmuki, Patrik, Lačnjevac, Uroš, "Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance", 15, no. 26 (2023):31459-31469,
https://doi.org/10.1021/acsami.3c04498 . .

TY  - JOUR
AU  - Marinkovic, Filip
AU  - Popovic, Dusan
AU  - Jovanovic, Jelena
AU  - Stankovic, Branislav
AU  - Jevtić, Sanja
AU  - Adnadjevic, Borivoj
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4998
AB  - The effect of the weight fraction of NaA zeolite on thermal properties (specific heat capacity, thermal diffusivity, thermal conductivity) and dielectric properties (electrical conductivity, real and imaginary electric permittivity) of composites based on low-density polyethylene (LDPE) and NaA zeolite is examined. Composite samples containing from 5 to 30 wt% zeolite are prepared using the compression molding technique. The degree of dispersion and the weight fraction of filler in the LDPE/NaA zeolite composites are determined using X-ray diffraction. A linear decrease in the values of the specific heat capacity with an increase in the weight fraction of zeolite is observed using differential scanning calorimetry. The laser flash method is used to determine the thermal diffusivity of the composites. An increase in effective thermal diffusivity and abrupt increase in the range from 15 to 20 wt% of zeolite are established. It is demonstrated that effective thermal conductivity increases with an increase in the weight fraction of zeolite, and an abrupt increase in the range from 15 to 20 wt% is observed. Dielectric spectroscopy measurements are performed to determine the real and imaginary parts of permittivity. An increase of real and imaginary parts of permittivity of LDPE/NaA zeolite composites, with increasing weight fraction of zeolite, is established. Two relaxation peaks of the imaginary parts of permittivity of LDPE/NaA zeolite composites are detected. An increase of electrical conductivity with increasing weight fraction of zeolite and abrupt increase in the range 15 to 20 wt% are noticed. (c) 2021 Society of Industrial Chemistry.
T2  - Polymer International
T1  - Thermal and dielectric properties of low-density polyethylene/NaA zeolite composites
EP  - 73
IS  - 1
SP  - 66
VL  - 71
DO  - 10.1002/pi.6284
ER  - 

@article{
author = "Marinkovic, Filip and Popovic, Dusan and Jovanovic, Jelena and Stankovic, Branislav and Jevtić, Sanja and Adnadjevic, Borivoj",
year = "2022",
abstract = "The effect of the weight fraction of NaA zeolite on thermal properties (specific heat capacity, thermal diffusivity, thermal conductivity) and dielectric properties (electrical conductivity, real and imaginary electric permittivity) of composites based on low-density polyethylene (LDPE) and NaA zeolite is examined. Composite samples containing from 5 to 30 wt% zeolite are prepared using the compression molding technique. The degree of dispersion and the weight fraction of filler in the LDPE/NaA zeolite composites are determined using X-ray diffraction. A linear decrease in the values of the specific heat capacity with an increase in the weight fraction of zeolite is observed using differential scanning calorimetry. The laser flash method is used to determine the thermal diffusivity of the composites. An increase in effective thermal diffusivity and abrupt increase in the range from 15 to 20 wt% of zeolite are established. It is demonstrated that effective thermal conductivity increases with an increase in the weight fraction of zeolite, and an abrupt increase in the range from 15 to 20 wt% is observed. Dielectric spectroscopy measurements are performed to determine the real and imaginary parts of permittivity. An increase of real and imaginary parts of permittivity of LDPE/NaA zeolite composites, with increasing weight fraction of zeolite, is established. Two relaxation peaks of the imaginary parts of permittivity of LDPE/NaA zeolite composites are detected. An increase of electrical conductivity with increasing weight fraction of zeolite and abrupt increase in the range 15 to 20 wt% are noticed. (c) 2021 Society of Industrial Chemistry.",
journal = "Polymer International",
title = "Thermal and dielectric properties of low-density polyethylene/NaA zeolite composites",
pages = "73-66",
number = "1",
volume = "71",
doi = "10.1002/pi.6284"
}

Marinkovic, F., Popovic, D., Jovanovic, J., Stankovic, B., Jevtić, S.,& Adnadjevic, B.. (2022). Thermal and dielectric properties of low-density polyethylene/NaA zeolite composites. in Polymer International, 71(1), 66-73.
https://doi.org/10.1002/pi.6284

Marinkovic F, Popovic D, Jovanovic J, Stankovic B, Jevtić S, Adnadjevic B. Thermal and dielectric properties of low-density polyethylene/NaA zeolite composites. in Polymer International. 2022;71(1):66-73.
doi:10.1002/pi.6284 .

Marinkovic, Filip, Popovic, Dusan, Jovanovic, Jelena, Stankovic, Branislav, Jevtić, Sanja, Adnadjevic, Borivoj, "Thermal and dielectric properties of low-density polyethylene/NaA zeolite composites" in Polymer International, 71, no. 1 (2022):66-73,
https://doi.org/10.1002/pi.6284 . .

TY  - JOUR
AU  - Petkovic-Benazzouz, Marija M.
AU  - Rakic, Aleksandra A.
AU  - Trišović, Nemanja
AU  - Zaric, Bozidarka L.
AU  - Janjic, Goran
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4835
AB  - Coordination effects have been considered through the most common interactions in the crystal structures of fluoro compounds (C-H/F and F/F interactions). The supramolecular profile of these effects is based on quantum-chemical calculations for the assessment of the interaction strength and electrostatic potential maps, which provide a qualitative insight into the examined effect. Coordination of aliphatic fluorides leads to an increase of the negative potential of the F atoms, and, hence, an increase in the hydrogen-bonding acceptor ability (strengthening of C-H/F interactions) and a weakening of the F/F interactions, due to an increase in repulsive interactions between the F atoms. There is no significant change in the potential of the F atoms due to coordination of C-6-aromatic fluorides, as in the case of aliphatic ones. This results in slight changes in the strengths of the C-H/F and F/F interactions (coupled with parallel interaction at large offsets, PILO), in a noticeable enhancement of stacking interactions, as well as in a significant enhancement of interactions involving the pi-system (F/pi - and C-H/pi interactions). It has also been shown that a decrease in the charge of the metal ions leads to a decrease in the negative potential of the F atom and also that the nature of the metal ion has a significant influence on the value of the potential of the F atoms.
T2  - Crystal Growth & Design
T1  - Supramolecular Perspective of Coordination Effects on Fluorine Interactions
EP  - 6142
IS  - 11
SP  - 6129
VL  - 21
DO  - 10.1021/acs.cgd.1c00584
ER  - 

@article{
author = "Petkovic-Benazzouz, Marija M. and Rakic, Aleksandra A. and Trišović, Nemanja and Zaric, Bozidarka L. and Janjic, Goran",
year = "2021",
abstract = "Coordination effects have been considered through the most common interactions in the crystal structures of fluoro compounds (C-H/F and F/F interactions). The supramolecular profile of these effects is based on quantum-chemical calculations for the assessment of the interaction strength and electrostatic potential maps, which provide a qualitative insight into the examined effect. Coordination of aliphatic fluorides leads to an increase of the negative potential of the F atoms, and, hence, an increase in the hydrogen-bonding acceptor ability (strengthening of C-H/F interactions) and a weakening of the F/F interactions, due to an increase in repulsive interactions between the F atoms. There is no significant change in the potential of the F atoms due to coordination of C-6-aromatic fluorides, as in the case of aliphatic ones. This results in slight changes in the strengths of the C-H/F and F/F interactions (coupled with parallel interaction at large offsets, PILO), in a noticeable enhancement of stacking interactions, as well as in a significant enhancement of interactions involving the pi-system (F/pi - and C-H/pi interactions). It has also been shown that a decrease in the charge of the metal ions leads to a decrease in the negative potential of the F atom and also that the nature of the metal ion has a significant influence on the value of the potential of the F atoms.",
journal = "Crystal Growth & Design",
title = "Supramolecular Perspective of Coordination Effects on Fluorine Interactions",
pages = "6142-6129",
number = "11",
volume = "21",
doi = "10.1021/acs.cgd.1c00584"
}

Petkovic-Benazzouz, M. M., Rakic, A. A., Trišović, N., Zaric, B. L.,& Janjic, G.. (2021). Supramolecular Perspective of Coordination Effects on Fluorine Interactions. in Crystal Growth & Design, 21(11), 6129-6142.
https://doi.org/10.1021/acs.cgd.1c00584

Petkovic-Benazzouz MM, Rakic AA, Trišović N, Zaric BL, Janjic G. Supramolecular Perspective of Coordination Effects on Fluorine Interactions. in Crystal Growth & Design. 2021;21(11):6129-6142.
doi:10.1021/acs.cgd.1c00584 .

Petkovic-Benazzouz, Marija M., Rakic, Aleksandra A., Trišović, Nemanja, Zaric, Bozidarka L., Janjic, Goran, "Supramolecular Perspective of Coordination Effects on Fluorine Interactions" in Crystal Growth & Design, 21, no. 11 (2021):6129-6142,
https://doi.org/10.1021/acs.cgd.1c00584 . .

TY  - JOUR
AU  - Mitić, Marko
AU  - Milovanović, Milan
AU  - Veljković, Filip M.
AU  - Perić-Grujić, Aleksandra
AU  - Veličković, Suzana
AU  - Jerosimić, Stanka
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4512
AB  - In the present paper, the results of combined theoretical and experimental investigation of small non-stoichiometric bromine-doped potassium clusters are reported. Potassium-bromide clusters were obtained by the Knudsen cell combined with surface ionization in the temperature range of 1000-1600 K, and selected by a magnetic sector mass spectrometer. Positive ions of KnBr (n = 3-6) and KnBrn-1 (n = 3-5) clusters were detected for the first time in one set measurement. In order to reveal the geometrical structure of each type of detected cluster, the randomized search algorithm was employed to survey the (Born-Oppenheimer) potential energy surface of both the neutral and cationic KnBr(0,1+) (n = 1-6) and KnBrn-1(0,1+) (n=3 5) clusters, followed by Density functional theory geometry optimizations, and many lowest-energy conformational isomers are presented. From the total electronic energies of clusters computed by the ab initio RCCSD(T)/ECP10MDF(K),cc-pVTZ-PP(Br) method at obtained equilibrium nuclear geometries, the following stability parameters of clusters were computed: their relative energies, the adiabatic and vertical ionization energies, binding energies per atom, and dissociation energies. Both experimental and theoretical results have shown that the title clusters belong to the group of "superalkali" clusters.
PB  - Elsevier Science Sa, Lausanne
T2  - Journal of Alloys and Compounds
T1  - Theoretical and experimental study of small potassium-bromide KnBr(0,1+) (n=2-6) and KnBrn-1(0,1+) (n=3-5) clusters
VL  - 835
DO  - 10.1016/j.jallcom.2020.155301
ER  - 

@article{
author = "Mitić, Marko and Milovanović, Milan and Veljković, Filip M. and Perić-Grujić, Aleksandra and Veličković, Suzana and Jerosimić, Stanka",
year = "2020",
abstract = "In the present paper, the results of combined theoretical and experimental investigation of small non-stoichiometric bromine-doped potassium clusters are reported. Potassium-bromide clusters were obtained by the Knudsen cell combined with surface ionization in the temperature range of 1000-1600 K, and selected by a magnetic sector mass spectrometer. Positive ions of KnBr (n = 3-6) and KnBrn-1 (n = 3-5) clusters were detected for the first time in one set measurement. In order to reveal the geometrical structure of each type of detected cluster, the randomized search algorithm was employed to survey the (Born-Oppenheimer) potential energy surface of both the neutral and cationic KnBr(0,1+) (n = 1-6) and KnBrn-1(0,1+) (n=3 5) clusters, followed by Density functional theory geometry optimizations, and many lowest-energy conformational isomers are presented. From the total electronic energies of clusters computed by the ab initio RCCSD(T)/ECP10MDF(K),cc-pVTZ-PP(Br) method at obtained equilibrium nuclear geometries, the following stability parameters of clusters were computed: their relative energies, the adiabatic and vertical ionization energies, binding energies per atom, and dissociation energies. Both experimental and theoretical results have shown that the title clusters belong to the group of "superalkali" clusters.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Journal of Alloys and Compounds",
title = "Theoretical and experimental study of small potassium-bromide KnBr(0,1+) (n=2-6) and KnBrn-1(0,1+) (n=3-5) clusters",
volume = "835",
doi = "10.1016/j.jallcom.2020.155301"
}

Mitić, M., Milovanović, M., Veljković, F. M., Perić-Grujić, A., Veličković, S.,& Jerosimić, S.. (2020). Theoretical and experimental study of small potassium-bromide KnBr(0,1+) (n=2-6) and KnBrn-1(0,1+) (n=3-5) clusters. in Journal of Alloys and Compounds
Elsevier Science Sa, Lausanne., 835.
https://doi.org/10.1016/j.jallcom.2020.155301

Mitić M, Milovanović M, Veljković FM, Perić-Grujić A, Veličković S, Jerosimić S. Theoretical and experimental study of small potassium-bromide KnBr(0,1+) (n=2-6) and KnBrn-1(0,1+) (n=3-5) clusters. in Journal of Alloys and Compounds. 2020;835.
doi:10.1016/j.jallcom.2020.155301 .

Mitić, Marko, Milovanović, Milan, Veljković, Filip M., Perić-Grujić, Aleksandra, Veličković, Suzana, Jerosimić, Stanka, "Theoretical and experimental study of small potassium-bromide KnBr(0,1+) (n=2-6) and KnBrn-1(0,1+) (n=3-5) clusters" in Journal of Alloys and Compounds, 835 (2020),
https://doi.org/10.1016/j.jallcom.2020.155301 . .