TY  - JOUR
AU  - Kalijadis, Ana
AU  - Jovanović, Zoran M.
AU  - Laušević, Mila
AU  - Laušević, Zoran
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5660
AB  - Boron was introduced into glassy carbon by chemical modification and by irradiating the precursor polymer with boron ions. Using chemical modification, a polymer with uniform distribution of boron in the bulk was obtained, whereas irradiation with B3+ produced a polymer with boron located in a narrow region under the surface. Following modification with boron, the samples were carbonized at 1273 K and examined using X-ray diffraction, Raman spectroscopy, temperature programmed desorption (TPD) and by hardness measurements. Structural analysis results suggest that boron is mostly substitutionally bonded in the glassy carbon structure regardless of the method used to introduce boron into the polymer precursor. Formation of crosslinks between glassy carbon ribbons during carbonization as a consequence of the recombination of ion beam induced changes in the polymer structure and a high concentration of boron in the subsurface layer is proposed to account for an increase of glassy carbon hardness. An increase in the total amount of surface oxygen groups was observed in the TPD spectra of both boron-modified samples due to an increase in the number of active sites. Results show that the nature of these sites is influenced by the initial distribution of boron in the polymer precursor. (C) 2011 Elsevier Ltd. All rights reserved.
PB  - Elsevier Ltd.
T2  - Carbon
T1  - The effect of boron incorporation on the structure and properties of glassy carbon
EP  - 2678
IS  - 8
SP  - 2671
VL  - 49
DO  - 10.1016/j.carbon.2011.02.054
ER  - 

@article{
author = "Kalijadis, Ana and Jovanović, Zoran M. and Laušević, Mila and Laušević, Zoran",
year = "2011",
abstract = "Boron was introduced into glassy carbon by chemical modification and by irradiating the precursor polymer with boron ions. Using chemical modification, a polymer with uniform distribution of boron in the bulk was obtained, whereas irradiation with B3+ produced a polymer with boron located in a narrow region under the surface. Following modification with boron, the samples were carbonized at 1273 K and examined using X-ray diffraction, Raman spectroscopy, temperature programmed desorption (TPD) and by hardness measurements. Structural analysis results suggest that boron is mostly substitutionally bonded in the glassy carbon structure regardless of the method used to introduce boron into the polymer precursor. Formation of crosslinks between glassy carbon ribbons during carbonization as a consequence of the recombination of ion beam induced changes in the polymer structure and a high concentration of boron in the subsurface layer is proposed to account for an increase of glassy carbon hardness. An increase in the total amount of surface oxygen groups was observed in the TPD spectra of both boron-modified samples due to an increase in the number of active sites. Results show that the nature of these sites is influenced by the initial distribution of boron in the polymer precursor. (C) 2011 Elsevier Ltd. All rights reserved.",
publisher = "Elsevier Ltd.",
journal = "Carbon",
title = "The effect of boron incorporation on the structure and properties of glassy carbon",
pages = "2678-2671",
number = "8",
volume = "49",
doi = "10.1016/j.carbon.2011.02.054"
}

Kalijadis, A., Jovanović, Z. M., Laušević, M.,& Laušević, Z.. (2011). The effect of boron incorporation on the structure and properties of glassy carbon. in Carbon
Elsevier Ltd.., 49(8), 2671-2678.
https://doi.org/10.1016/j.carbon.2011.02.054

Kalijadis A, Jovanović ZM, Laušević M, Laušević Z. The effect of boron incorporation on the structure and properties of glassy carbon. in Carbon. 2011;49(8):2671-2678.
doi:10.1016/j.carbon.2011.02.054 .

Kalijadis, Ana, Jovanović, Zoran M., Laušević, Mila, Laušević, Zoran, "The effect of boron incorporation on the structure and properties of glassy carbon" in Carbon, 49, no. 8 (2011):2671-2678,
https://doi.org/10.1016/j.carbon.2011.02.054 . .

TY  - JOUR
AU  - Jovanović, Zoran M.
AU  - Kalijadis, Ana
AU  - Laušević, Mila
AU  - Laušević, Zoran
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5661
AB  - Glassy carbon was irradiated with 15 key H(+) ion beam. It was observed that the implanted hydrogen is unstable in material and evolves as H, H(2) and H(2)O. Post-irradiation evolution of H, H(2) and H(2)O from proton irradiated glassy carbon was monitored by temperature programmed desorption (TPD) in the period of 30 days. In between irradiation and TPD measurements the irradiated samples were stored in air. The evolution of the molecular hydrogen, although the protons are implanted deeply below the surface of the disordered glassy carbon, proceeds over the same mechanism as in the case of low-energy H-atoms chemisorbed on the very surface of an ideal graphite structure. (C) 2011 Elsevier B.V. All rights reserved.
PB  - Elsevier B.V.
T2  - Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms
T1  - The evolution of hydrogen from proton irradiated glassy carbon
EP  - 2583
IS  - 21
SP  - 2578
VL  - 269
DO  - 10.1016/j.nimb.2011.07.014
ER  - 

@article{
author = "Jovanović, Zoran M. and Kalijadis, Ana and Laušević, Mila and Laušević, Zoran",
year = "2011",
abstract = "Glassy carbon was irradiated with 15 key H(+) ion beam. It was observed that the implanted hydrogen is unstable in material and evolves as H, H(2) and H(2)O. Post-irradiation evolution of H, H(2) and H(2)O from proton irradiated glassy carbon was monitored by temperature programmed desorption (TPD) in the period of 30 days. In between irradiation and TPD measurements the irradiated samples were stored in air. The evolution of the molecular hydrogen, although the protons are implanted deeply below the surface of the disordered glassy carbon, proceeds over the same mechanism as in the case of low-energy H-atoms chemisorbed on the very surface of an ideal graphite structure. (C) 2011 Elsevier B.V. All rights reserved.",
publisher = "Elsevier B.V.",
journal = "Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms",
title = "The evolution of hydrogen from proton irradiated glassy carbon",
pages = "2583-2578",
number = "21",
volume = "269",
doi = "10.1016/j.nimb.2011.07.014"
}

Jovanović, Z. M., Kalijadis, A., Laušević, M.,& Laušević, Z.. (2011). The evolution of hydrogen from proton irradiated glassy carbon. in Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms
Elsevier B.V.., 269(21), 2578-2583.
https://doi.org/10.1016/j.nimb.2011.07.014

Jovanović ZM, Kalijadis A, Laušević M, Laušević Z. The evolution of hydrogen from proton irradiated glassy carbon. in Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. 2011;269(21):2578-2583.
doi:10.1016/j.nimb.2011.07.014 .

Jovanović, Zoran M., Kalijadis, Ana, Laušević, Mila, Laušević, Zoran, "The evolution of hydrogen from proton irradiated glassy carbon" in Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms, 269, no. 21 (2011):2578-2583,
https://doi.org/10.1016/j.nimb.2011.07.014 . .

TY  - JOUR
AU  - Kalijadis, Ana
AU  - Vukčević, Marija
AU  - Jovanović, Zoran M.
AU  - Laušević, Zoran
AU  - Laušević, Mila
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1802
AB  - The surface characteristics of different carbon materials: activated carbon, carbon felt, glassy carbon and a porous carbon monolith were investigated. The specific surface area was examined by the BET method with N2 adsorption, the amount and the type of surface oxygen groups by Boehm titration as well as by temperature-programmed desorption (TPD). By comparing the results obtained using BET analysis with those of TPD and the Boehm method, it was found that the number of surface groups was not proportional to the specific surface area. The total amount of oxygen groups, obtained by TPD, is higher than the amount obtained by Boehm's method for porous samples. The inconsistencies between these results originate from the fact that the Boehm method is limited to the determination of acidic and basic groups, whereas TPD provides information on the total number of all surface oxygen groups. In addition, the presence of porosity could reduce the solvent-accessible surface in the Boehm method. The TPD profiles of CO evolution showed the presence of a low temperature maximum, below 650 K, which originates from CO2 reduction on the carbon material surface.
AB  - Ispitivane su površinske osobine različitih karbonskih materijala: aktivnog uglja, karbonskog filca, staklastog ugljenika i poroznog karbon monolita. Specifična površina uzoraka ispitivana je BET metodom, a količina i tip površinskih grupa Bemovim titracijama i temperaturski programiranom desorpcijom (TPD). Poredeći rezultate dobijene BET metodom sa rezultatima TPD-a i Bemove titracije, zaključeno je da broj površinskih grupa nije proporcionalan specifičnoj površini uzoraka. Ukupan broj kiseoničnih grupa kod poroznih uzoraka, dobijen na osnovu TPD-a, je veći nego u slučaju Bemovih titracija. Razlog neslaganja rezultata ovih dveju metoda potiče iz činjenice da je Bemov metod ograničen na određivanje samo kiselih i baznih grupa, dok TPD daje informaciju o ukupnom broju svih kiseoničnih grupa. Takođe, kod Bemovog metoda, postojanje poroznosti može smanjiti rastvoru dostupnu površinu. TPD spektri izdvajanja SO pokazali su nisko-temperaturski maksimum, ispod 650 K, koji potiče od redukcije SO2 na površini karbonskog materijala.
PB  - Serbian Chemical Society, Belgrade
T2  - Journal of the Serbian Chemical Society
T1  - Characterisation of surface oxygen groups on different carbon materials by the Boehm method and temperature-programmed desorption
T1  - Karakterizacija površinskih kiseoničnih grupa različitih karbonskih materijala Bemovom (Boehm) metodom i temperaturski programiranom desorpcijom
EP  - 768
IS  - 5
SP  - 757
VL  - 76
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1802
ER  - 

@article{
author = "Kalijadis, Ana and Vukčević, Marija and Jovanović, Zoran M. and Laušević, Zoran and Laušević, Mila",
year = "2011",
abstract = "The surface characteristics of different carbon materials: activated carbon, carbon felt, glassy carbon and a porous carbon monolith were investigated. The specific surface area was examined by the BET method with N2 adsorption, the amount and the type of surface oxygen groups by Boehm titration as well as by temperature-programmed desorption (TPD). By comparing the results obtained using BET analysis with those of TPD and the Boehm method, it was found that the number of surface groups was not proportional to the specific surface area. The total amount of oxygen groups, obtained by TPD, is higher than the amount obtained by Boehm's method for porous samples. The inconsistencies between these results originate from the fact that the Boehm method is limited to the determination of acidic and basic groups, whereas TPD provides information on the total number of all surface oxygen groups. In addition, the presence of porosity could reduce the solvent-accessible surface in the Boehm method. The TPD profiles of CO evolution showed the presence of a low temperature maximum, below 650 K, which originates from CO2 reduction on the carbon material surface., Ispitivane su površinske osobine različitih karbonskih materijala: aktivnog uglja, karbonskog filca, staklastog ugljenika i poroznog karbon monolita. Specifična površina uzoraka ispitivana je BET metodom, a količina i tip površinskih grupa Bemovim titracijama i temperaturski programiranom desorpcijom (TPD). Poredeći rezultate dobijene BET metodom sa rezultatima TPD-a i Bemove titracije, zaključeno je da broj površinskih grupa nije proporcionalan specifičnoj površini uzoraka. Ukupan broj kiseoničnih grupa kod poroznih uzoraka, dobijen na osnovu TPD-a, je veći nego u slučaju Bemovih titracija. Razlog neslaganja rezultata ovih dveju metoda potiče iz činjenice da je Bemov metod ograničen na određivanje samo kiselih i baznih grupa, dok TPD daje informaciju o ukupnom broju svih kiseoničnih grupa. Takođe, kod Bemovog metoda, postojanje poroznosti može smanjiti rastvoru dostupnu površinu. TPD spektri izdvajanja SO pokazali su nisko-temperaturski maksimum, ispod 650 K, koji potiče od redukcije SO2 na površini karbonskog materijala.",
publisher = "Serbian Chemical Society, Belgrade",
journal = "Journal of the Serbian Chemical Society",
title = "Characterisation of surface oxygen groups on different carbon materials by the Boehm method and temperature-programmed desorption, Karakterizacija površinskih kiseoničnih grupa različitih karbonskih materijala Bemovom (Boehm) metodom i temperaturski programiranom desorpcijom",
pages = "768-757",
number = "5",
volume = "76",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1802"
}

Kalijadis, A., Vukčević, M., Jovanović, Z. M., Laušević, Z.,& Laušević, M.. (2011). Characterisation of surface oxygen groups on different carbon materials by the Boehm method and temperature-programmed desorption. in Journal of the Serbian Chemical Society
Serbian Chemical Society, Belgrade., 76(5), 757-768.
https://hdl.handle.net/21.15107/rcub_technorep_1802

Kalijadis A, Vukčević M, Jovanović ZM, Laušević Z, Laušević M. Characterisation of surface oxygen groups on different carbon materials by the Boehm method and temperature-programmed desorption. in Journal of the Serbian Chemical Society. 2011;76(5):757-768.
https://hdl.handle.net/21.15107/rcub_technorep_1802 .

Kalijadis, Ana, Vukčević, Marija, Jovanović, Zoran M., Laušević, Zoran, Laušević, Mila, "Characterisation of surface oxygen groups on different carbon materials by the Boehm method and temperature-programmed desorption" in Journal of the Serbian Chemical Society, 76, no. 5 (2011):757-768,
https://hdl.handle.net/21.15107/rcub_technorep_1802 .