TY  - JOUR
AU  - Pavlović, Vera P.
AU  - Krstić, Jugoslav
AU  - Šćepanović, M. J.
AU  - Dojčilović, Jablan R.
AU  - Minić, Dragica M.
AU  - Blanuša, Jovan
AU  - Stevanović, Suzana
AU  - Mitić, Vojislav V.
AU  - Pavlović, Vladimir B.
PY  - 2011
UR  - https://dais.sanu.ac.rs/123456789/736
AB  - In this article, in order to obtain tetragonal nanocrystalline BaTiO3, structural investigations of mechanically activated BaTiO3 powder have been performed. A mercury porosimetry analysis and scanning electron microscopy method have been applied for determination of the specific pore volume, porosity and microstructure morphology of the samples. The lattice vibration spectra of nonactivated and activated powders, their phase composition, lattice microstrains and the mean size of coherently diffracting domains were examined by Raman spectroscopy and the X-ray powder diffraction method. The average crystal structure of obtained nanocrystalline powders, estimated from X-ray diffraction data, gave evidence of retained, but slightly sustained tetragonality of powders, even for particles as small as ∼30 nm. Raman spectroscopy also gave clear evidence for local tetragonal symmetries, in particular through the presence of a band at ∼307 cm−1.
PB  - Elsevier
T2  - Ceramics International
T1  - Structural Investigation of Mechanically Activated Nanocrystalline BaTiO3 Powders
SP  - 2513
EP  - 2518
VL  - 37
IS  - 7
DO  - 10.1016/j.ceramint.2011.03.064
UR  - https://hdl.handle.net/21.15107/rcub_dais_736
ER  - 

@article{
author = "Pavlović, Vera P. and Krstić, Jugoslav and Šćepanović, M. J. and Dojčilović, Jablan R. and Minić, Dragica M. and Blanuša, Jovan and Stevanović, Suzana and Mitić, Vojislav V. and Pavlović, Vladimir B.",
year = "2011",
abstract = "In this article, in order to obtain tetragonal nanocrystalline BaTiO3, structural investigations of mechanically activated BaTiO3 powder have been performed. A mercury porosimetry analysis and scanning electron microscopy method have been applied for determination of the specific pore volume, porosity and microstructure morphology of the samples. The lattice vibration spectra of nonactivated and activated powders, their phase composition, lattice microstrains and the mean size of coherently diffracting domains were examined by Raman spectroscopy and the X-ray powder diffraction method. The average crystal structure of obtained nanocrystalline powders, estimated from X-ray diffraction data, gave evidence of retained, but slightly sustained tetragonality of powders, even for particles as small as ∼30 nm. Raman spectroscopy also gave clear evidence for local tetragonal symmetries, in particular through the presence of a band at ∼307 cm−1.",
publisher = "Elsevier",
journal = "Ceramics International",
title = "Structural Investigation of Mechanically Activated Nanocrystalline BaTiO3 Powders",
pages = "2513-2518",
volume = "37",
number = "7",
doi = "10.1016/j.ceramint.2011.03.064",
url = "https://hdl.handle.net/21.15107/rcub_dais_736"
}

Pavlović, V. P., Krstić, J., Šćepanović, M. J., Dojčilović, J. R., Minić, D. M., Blanuša, J., Stevanović, S., Mitić, V. V.,& Pavlović, V. B.. (2011). Structural Investigation of Mechanically Activated Nanocrystalline BaTiO3 Powders. in Ceramics International
Elsevier., 37(7), 2513-2518.
https://doi.org/10.1016/j.ceramint.2011.03.064
https://hdl.handle.net/21.15107/rcub_dais_736

Pavlović VP, Krstić J, Šćepanović MJ, Dojčilović JR, Minić DM, Blanuša J, Stevanović S, Mitić VV, Pavlović VB. Structural Investigation of Mechanically Activated Nanocrystalline BaTiO3 Powders. in Ceramics International. 2011;37(7):2513-2518.
doi:10.1016/j.ceramint.2011.03.064
https://hdl.handle.net/21.15107/rcub_dais_736 .

Pavlović, Vera P., Krstić, Jugoslav, Šćepanović, M. J., Dojčilović, Jablan R., Minić, Dragica M., Blanuša, Jovan, Stevanović, Suzana, Mitić, Vojislav V., Pavlović, Vladimir B., "Structural Investigation of Mechanically Activated Nanocrystalline BaTiO3 Powders" in Ceramics International, 37, no. 7 (2011):2513-2518,
https://doi.org/10.1016/j.ceramint.2011.03.064 .,
https://hdl.handle.net/21.15107/rcub_dais_736 .

TY  - JOUR
AU  - Milićević, Dejan S.
AU  - Trifunović, Saša B.
AU  - Mudrinić, Tihana M.
AU  - Leskovac, Andreja
AU  - Ignjatović, Nenad
AU  - Dojčilović, Jablan R.
AU  - Suljovrujić, Edin H.
PY  - 2010
UR  - https://dais.sanu.ac.rs/123456789/2756
AB  - U ovom radu ispitivan je uticaj gama zračenja na molekulsku masu i staklasti prelaz poli-L-laktida (PLLA). S obzirom da je PLLA pri izlaganju visokoenergijskom zračenju sklon kidanju lanaca i velikoj degradaciji, promene u molekulskoj masi su određene primenom gel propusne hromatografije (GPC). Radijaciono-indukovane promene u staklastom prelazu su ispitane pomoću diferencijalno skenirajuće kalorimetrije (DSC). Prividna aktivaciona energija za staklasti prelaz, ΔH*, određena je na osnovu zavisnosti temperature staklastog prelaza, Tg, od brzine zagrevanja. Kidanje lanaca, uzrokovano zračenjem, glavni je razlog opadanja Tg i ΔH*sa apsorbovanom dozom. Izazvane promene u molekulskoj masi i temperaturi staklastog prelaza odigravaju se na predvidljiv i prilično precizan način. Stoga, gama zračenje može biti korišćeno ne samo za sterilizaciju nego i za dobijanje ovog biomaterijala poželjnih karakteristika.
AB  - The influence of gamma radiation on the structure and glass transition behaviour of poly-L-lactide (PLLA) has been studied. Since PLLA exposed to high-energy radiation in the presence of air is prone to chain scission reactions and large degradation, changes in molecular weight were obtained by the gel permeation chromatography (GPC). Alterations in the glass transition behaviour were investigated by differential scanning calorimetry (DSC). The apparent activation energy, Delta H*, for the glass transition was determined on the basis of the heating rate dependence of the glass transition temperature, T(g). Our findings support the fact that chain scission is the main reason for the decrease of Tg and Delta H* with the absorbed dose. At low doses, despite large changes in molecular weight, only small alterations are observed in the glass transition temperature and apparent activation energy. Further increase in the absorbed dose introduces not only significant changes in the molecular weight but also in the glass transition temperature and the activation energy. Such glass transition behaviour is a manifestation of a well-known effect of molecular weight on Tg, postulated by the Fox-Flory equation. However, all the observed alterations are small and tolerable at absorbed doses required for sterilization (up to 25 kGy in most circumstances). Furthermore, this study reveals that the radiation-induced changes in the molecular weight and the glass transition temperature occur in a predictable and fairly accurate manner. Therefore, gamma radiation can be used not only for sterilization but also for tailoring desirable end-use properties of PLLA based implants.
T2  - Hemijska industrija
T1  - Uticaj gama zračenja na molekulsku masu i staklasti prelaz PLLA
SP  - 275
EP  - 281
VL  - 64
IS  - 4
DO  - 10.2298/HEMIND100329020M
UR  - https://hdl.handle.net/21.15107/rcub_dais_2756
ER  - 

@article{
author = "Milićević, Dejan S. and Trifunović, Saša B. and Mudrinić, Tihana M. and Leskovac, Andreja and Ignjatović, Nenad and Dojčilović, Jablan R. and Suljovrujić, Edin H.",
year = "2010",
abstract = "U ovom radu ispitivan je uticaj gama zračenja na molekulsku masu i staklasti prelaz poli-L-laktida (PLLA). S obzirom da je PLLA pri izlaganju visokoenergijskom zračenju sklon kidanju lanaca i velikoj degradaciji, promene u molekulskoj masi su određene primenom gel propusne hromatografije (GPC). Radijaciono-indukovane promene u staklastom prelazu su ispitane pomoću diferencijalno skenirajuće kalorimetrije (DSC). Prividna aktivaciona energija za staklasti prelaz, ΔH*, određena je na osnovu zavisnosti temperature staklastog prelaza, Tg, od brzine zagrevanja. Kidanje lanaca, uzrokovano zračenjem, glavni je razlog opadanja Tg i ΔH*sa apsorbovanom dozom. Izazvane promene u molekulskoj masi i temperaturi staklastog prelaza odigravaju se na predvidljiv i prilično precizan način. Stoga, gama zračenje može biti korišćeno ne samo za sterilizaciju nego i za dobijanje ovog biomaterijala poželjnih karakteristika., The influence of gamma radiation on the structure and glass transition behaviour of poly-L-lactide (PLLA) has been studied. Since PLLA exposed to high-energy radiation in the presence of air is prone to chain scission reactions and large degradation, changes in molecular weight were obtained by the gel permeation chromatography (GPC). Alterations in the glass transition behaviour were investigated by differential scanning calorimetry (DSC). The apparent activation energy, Delta H*, for the glass transition was determined on the basis of the heating rate dependence of the glass transition temperature, T(g). Our findings support the fact that chain scission is the main reason for the decrease of Tg and Delta H* with the absorbed dose. At low doses, despite large changes in molecular weight, only small alterations are observed in the glass transition temperature and apparent activation energy. Further increase in the absorbed dose introduces not only significant changes in the molecular weight but also in the glass transition temperature and the activation energy. Such glass transition behaviour is a manifestation of a well-known effect of molecular weight on Tg, postulated by the Fox-Flory equation. However, all the observed alterations are small and tolerable at absorbed doses required for sterilization (up to 25 kGy in most circumstances). Furthermore, this study reveals that the radiation-induced changes in the molecular weight and the glass transition temperature occur in a predictable and fairly accurate manner. Therefore, gamma radiation can be used not only for sterilization but also for tailoring desirable end-use properties of PLLA based implants.",
journal = "Hemijska industrija",
title = "Uticaj gama zračenja na molekulsku masu i staklasti prelaz PLLA",
pages = "275-281",
volume = "64",
number = "4",
doi = "10.2298/HEMIND100329020M",
url = "https://hdl.handle.net/21.15107/rcub_dais_2756"
}

Milićević, D. S., Trifunović, S. B., Mudrinić, T. M., Leskovac, A., Ignjatović, N., Dojčilović, J. R.,& Suljovrujić, E. H.. (2010). Uticaj gama zračenja na molekulsku masu i staklasti prelaz PLLA. in Hemijska industrija, 64(4), 275-281.
https://doi.org/10.2298/HEMIND100329020M
https://hdl.handle.net/21.15107/rcub_dais_2756

Milićević DS, Trifunović SB, Mudrinić TM, Leskovac A, Ignjatović N, Dojčilović JR, Suljovrujić EH. Uticaj gama zračenja na molekulsku masu i staklasti prelaz PLLA. in Hemijska industrija. 2010;64(4):275-281.
doi:10.2298/HEMIND100329020M
https://hdl.handle.net/21.15107/rcub_dais_2756 .

Milićević, Dejan S., Trifunović, Saša B., Mudrinić, Tihana M., Leskovac, Andreja, Ignjatović, Nenad, Dojčilović, Jablan R., Suljovrujić, Edin H., "Uticaj gama zračenja na molekulsku masu i staklasti prelaz PLLA" in Hemijska industrija, 64, no. 4 (2010):275-281,
https://doi.org/10.2298/HEMIND100329020M .,
https://hdl.handle.net/21.15107/rcub_dais_2756 .

TY  - JOUR
AU  - Milićević, Dejan S.
AU  - Trifunović, S.
AU  - Dojčilović, Jablan R.
AU  - Ignjatović, Nenad
AU  - Suljovrujić, Edin H.
PY  - 2010
UR  - https://dais.sanu.ac.rs/123456789/2755
AB  - The influence of gamma radiation on the molecular weight and glass transition behaviour of poly-L-lactide (PLLA) and hydroxyapatite/poly-L-lactide (HAp/PLLA) nanocomposite has been studied Since PLLA exposed to high-energy radiation in the presence of air is prone to chain scission reactions and large degradation, changes in molecular weight were obtained by gel permeation chromatography (GPC). Alterations in the glass transition behaviour were investigated by differential scanning calorimetry (DSC) The apparent activation energy (Delta H*) for glass transition was determined on the basis of the heating rate dependence of the glass transition temperature (T-g). Our findings support the fact that chain scission is the main reason for the decrease of T-g and Delta H* with the absorbed dose Furthermore, more intensive chain scission degradation of PLLA was observed in HAp/PLLA and can only be ascribed to the presence of HAp nanoparticles. Consequently, initial differences in the glass transition temperature and/or apparent activation energy of PLLA and HAp/PLLA became more pronounced with absorbed dose. This study reveals that radiation-induced changes in molecular weight and glass transition temperature occur in a predictable and fairly accurate manner Therefore, gamma radiation can be used not only for sterilization but also for tailoring desirable end-use properties of these biomaterials (C) 2010 Elsevier B V. All rights reserved
T2  - Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms
T1  - The influence of gamma radiation on the molecular weight and glass transition of PLLA and HAp/PLLA nanocomposite
SP  - 2744
EP  - 2749
VL  - 268
IS  - 17-18
DO  - 10.1016/j.nimb.2010.06.036
UR  - https://hdl.handle.net/21.15107/rcub_dais_2755
ER  - 

@article{
author = "Milićević, Dejan S. and Trifunović, S. and Dojčilović, Jablan R. and Ignjatović, Nenad and Suljovrujić, Edin H.",
year = "2010",
abstract = "The influence of gamma radiation on the molecular weight and glass transition behaviour of poly-L-lactide (PLLA) and hydroxyapatite/poly-L-lactide (HAp/PLLA) nanocomposite has been studied Since PLLA exposed to high-energy radiation in the presence of air is prone to chain scission reactions and large degradation, changes in molecular weight were obtained by gel permeation chromatography (GPC). Alterations in the glass transition behaviour were investigated by differential scanning calorimetry (DSC) The apparent activation energy (Delta H*) for glass transition was determined on the basis of the heating rate dependence of the glass transition temperature (T-g). Our findings support the fact that chain scission is the main reason for the decrease of T-g and Delta H* with the absorbed dose Furthermore, more intensive chain scission degradation of PLLA was observed in HAp/PLLA and can only be ascribed to the presence of HAp nanoparticles. Consequently, initial differences in the glass transition temperature and/or apparent activation energy of PLLA and HAp/PLLA became more pronounced with absorbed dose. This study reveals that radiation-induced changes in molecular weight and glass transition temperature occur in a predictable and fairly accurate manner Therefore, gamma radiation can be used not only for sterilization but also for tailoring desirable end-use properties of these biomaterials (C) 2010 Elsevier B V. All rights reserved",
journal = "Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms",
title = "The influence of gamma radiation on the molecular weight and glass transition of PLLA and HAp/PLLA nanocomposite",
pages = "2744-2749",
volume = "268",
number = "17-18",
doi = "10.1016/j.nimb.2010.06.036",
url = "https://hdl.handle.net/21.15107/rcub_dais_2755"
}

Milićević, D. S., Trifunović, S., Dojčilović, J. R., Ignjatović, N.,& Suljovrujić, E. H.. (2010). The influence of gamma radiation on the molecular weight and glass transition of PLLA and HAp/PLLA nanocomposite. in Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms, 268(17-18), 2744-2749.
https://doi.org/10.1016/j.nimb.2010.06.036
https://hdl.handle.net/21.15107/rcub_dais_2755

Milićević DS, Trifunović S, Dojčilović JR, Ignjatović N, Suljovrujić EH. The influence of gamma radiation on the molecular weight and glass transition of PLLA and HAp/PLLA nanocomposite. in Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. 2010;268(17-18):2744-2749.
doi:10.1016/j.nimb.2010.06.036
https://hdl.handle.net/21.15107/rcub_dais_2755 .

Milićević, Dejan S., Trifunović, S., Dojčilović, Jablan R., Ignjatović, Nenad, Suljovrujić, Edin H., "The influence of gamma radiation on the molecular weight and glass transition of PLLA and HAp/PLLA nanocomposite" in Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms, 268, no. 17-18 (2010):2744-2749,
https://doi.org/10.1016/j.nimb.2010.06.036 .,
https://hdl.handle.net/21.15107/rcub_dais_2755 .