TY  - JOUR
AU  - Janković-Častvan, Ivona
AU  - Lazarević, Slavica
AU  - Jordović, Branka
AU  - Petrović, R.
AU  - Tanasković, Dušanka
AU  - Janaćković, Đorđe
PY  - 2007
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1180
AB  - Cordierite ceramic material, due to its properties such as low thermal expansion coefficient, low dielectric constant and high specific resistivity, could be used as an insulating material in high-frequency electronics. as well as a substrate for integrated circuits and electronic modules. In this paper, cordierite (2MgO center dot 2A1(2)O(3)center dot 5SiO(2)) was synthesized by the non-hydrolytic sol-gel process combined with solvothermal treatment starting from aluminium chloride, TEOS and magnesium chloride dissolved in absolute ethanol. Crystallization of mu-cordierite from gel occurred at temperatures between 900 and 1000 degrees C and a higher calcination temperature resulted in the transformation of mu-cordierite to alpha-cordierite. Cordierite material obtained by sintering of powder in the temperature range from 1400 to 1450 degrees C showed values of the dielectric constants from 7.93 to 3.78 and values of dielectric loss tangents from 0.049 to 0.001.
PB  - Elsevier Sci Ltd, Oxford
T2  - Journal of the European Ceramic Society
T1  - Electrical properties of cordierite obtained by non-hydrolytic sol-gel method
EP  - 3661
IS  - 13-15
SP  - 3659
VL  - 27
DO  - 10.1016/j.jeurceramsoc.2007.02.018
ER  - 

@article{
author = "Janković-Častvan, Ivona and Lazarević, Slavica and Jordović, Branka and Petrović, R. and Tanasković, Dušanka and Janaćković, Đorđe",
year = "2007",
abstract = "Cordierite ceramic material, due to its properties such as low thermal expansion coefficient, low dielectric constant and high specific resistivity, could be used as an insulating material in high-frequency electronics. as well as a substrate for integrated circuits and electronic modules. In this paper, cordierite (2MgO center dot 2A1(2)O(3)center dot 5SiO(2)) was synthesized by the non-hydrolytic sol-gel process combined with solvothermal treatment starting from aluminium chloride, TEOS and magnesium chloride dissolved in absolute ethanol. Crystallization of mu-cordierite from gel occurred at temperatures between 900 and 1000 degrees C and a higher calcination temperature resulted in the transformation of mu-cordierite to alpha-cordierite. Cordierite material obtained by sintering of powder in the temperature range from 1400 to 1450 degrees C showed values of the dielectric constants from 7.93 to 3.78 and values of dielectric loss tangents from 0.049 to 0.001.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Journal of the European Ceramic Society",
title = "Electrical properties of cordierite obtained by non-hydrolytic sol-gel method",
pages = "3661-3659",
number = "13-15",
volume = "27",
doi = "10.1016/j.jeurceramsoc.2007.02.018"
}

Janković-Častvan, I., Lazarević, S., Jordović, B., Petrović, R., Tanasković, D.,& Janaćković, Đ.. (2007). Electrical properties of cordierite obtained by non-hydrolytic sol-gel method. in Journal of the European Ceramic Society
Elsevier Sci Ltd, Oxford., 27(13-15), 3659-3661.
https://doi.org/10.1016/j.jeurceramsoc.2007.02.018

Janković-Častvan I, Lazarević S, Jordović B, Petrović R, Tanasković D, Janaćković Đ. Electrical properties of cordierite obtained by non-hydrolytic sol-gel method. in Journal of the European Ceramic Society. 2007;27(13-15):3659-3661.
doi:10.1016/j.jeurceramsoc.2007.02.018 .

Janković-Častvan, Ivona, Lazarević, Slavica, Jordović, Branka, Petrović, R., Tanasković, Dušanka, Janaćković, Đorđe, "Electrical properties of cordierite obtained by non-hydrolytic sol-gel method" in Journal of the European Ceramic Society, 27, no. 13-15 (2007):3659-3661,
https://doi.org/10.1016/j.jeurceramsoc.2007.02.018 . .

TY  - JOUR
AU  - Stojanović, D.
AU  - Jokić, Bojan
AU  - Veljović, Đorđe
AU  - Petrović, R.
AU  - Uskoković, Petar
AU  - Janaćković, Đorđe
PY  - 2007
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1120
AB  - Titanium and titanium alloys are widely used as materials for implants, because of their mechanical properties and nontoxic behaviour, but unfortunately, are bioinert. In order to solve this problem, the metal implant could be coated with bioactive materials with good adhesion to metal and could be also bonded interfacially to the bone. The aim of this work is to investigate the synthesis of functionally graded glass-apatite coating on Ti6A14V alloys by the electrophoretic method. In order to enhance bioactivity of the surface, nanostructured hydroxyapatite particles were embedded in the glass coating. The influence of synthesis condition such as deposition voltage and time on the coating properties and deposit weights were examined. It was shown that controlling the deposition voltage and time, the deposition weight and thickness of coating could be controlled. It was shown that electrophoretic deposition can be successfully employed for the preparation graded glass-apatite coating on Ti6A14V substrate.
PB  - Elsevier Sci Ltd, Oxford
T2  - Journal of the European Ceramic Society
T1  - Bioactive glass-apatite composite coating for titanium implant synthesized by electrophoretic deposition
EP  - 1599
IS  - 2-3
SP  - 1595
VL  - 27
DO  - 10.1016/j.jeurceramsoc.2006.04.111
ER  - 

@article{
author = "Stojanović, D. and Jokić, Bojan and Veljović, Đorđe and Petrović, R. and Uskoković, Petar and Janaćković, Đorđe",
year = "2007",
abstract = "Titanium and titanium alloys are widely used as materials for implants, because of their mechanical properties and nontoxic behaviour, but unfortunately, are bioinert. In order to solve this problem, the metal implant could be coated with bioactive materials with good adhesion to metal and could be also bonded interfacially to the bone. The aim of this work is to investigate the synthesis of functionally graded glass-apatite coating on Ti6A14V alloys by the electrophoretic method. In order to enhance bioactivity of the surface, nanostructured hydroxyapatite particles were embedded in the glass coating. The influence of synthesis condition such as deposition voltage and time on the coating properties and deposit weights were examined. It was shown that controlling the deposition voltage and time, the deposition weight and thickness of coating could be controlled. It was shown that electrophoretic deposition can be successfully employed for the preparation graded glass-apatite coating on Ti6A14V substrate.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Journal of the European Ceramic Society",
title = "Bioactive glass-apatite composite coating for titanium implant synthesized by electrophoretic deposition",
pages = "1599-1595",
number = "2-3",
volume = "27",
doi = "10.1016/j.jeurceramsoc.2006.04.111"
}

Stojanović, D., Jokić, B., Veljović, Đ., Petrović, R., Uskoković, P.,& Janaćković, Đ.. (2007). Bioactive glass-apatite composite coating for titanium implant synthesized by electrophoretic deposition. in Journal of the European Ceramic Society
Elsevier Sci Ltd, Oxford., 27(2-3), 1595-1599.
https://doi.org/10.1016/j.jeurceramsoc.2006.04.111

Stojanović D, Jokić B, Veljović Đ, Petrović R, Uskoković P, Janaćković Đ. Bioactive glass-apatite composite coating for titanium implant synthesized by electrophoretic deposition. in Journal of the European Ceramic Society. 2007;27(2-3):1595-1599.
doi:10.1016/j.jeurceramsoc.2006.04.111 .

Stojanović, D., Jokić, Bojan, Veljović, Đorđe, Petrović, R., Uskoković, Petar, Janaćković, Đorđe, "Bioactive glass-apatite composite coating for titanium implant synthesized by electrophoretic deposition" in Journal of the European Ceramic Society, 27, no. 2-3 (2007):1595-1599,
https://doi.org/10.1016/j.jeurceramsoc.2006.04.111 . .

TY  - JOUR
AU  - Jokić, Bojan
AU  - Janković-Častvan, Ivona
AU  - Veljović, Đorđe
AU  - Petrović, R.
AU  - Drmanić, Saša
AU  - Janaćković, Đorđe
PY  - 2006
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/884
AB  - In this paper the synthesis of bioactive cement based on al-Ca-3(PO4)(2) (a-TCP) and calcium deficient hydroxyapatite (CDHAp), obtained by hydrothermal method from CaCl2, EDTA, NaH(2)PO(4)(.)12H(2)O and urea at 160 degrees C, was described. According to the results of DTA, SEM, X-ray and FTIR analyses performed in this investigation, it is shown that CDHAp is transformed to beta-TCP at 780 degrees C, and to a-TCP at 1400 degrees C. The hardening of the samples, prepared from the mixture of alpha-TCP and 2.5 % solution of Na2HPO4, in simulated body fluid at 37 degrees C, was followed by the microstructure changes.
PB  - Trans Tech Publications Ltd, Durnten-Zurich
T2  - Key Engineering Materials
T1  - Preparation of a-TCP cements from calcium deficient hydroxyapatite obtained by hydrothermal method
EP  - 824
SP  - 821
VL  - 309-311 II
DO  - 10.4028/0-87849-992-x.821
ER  - 

@article{
author = "Jokić, Bojan and Janković-Častvan, Ivona and Veljović, Đorđe and Petrović, R. and Drmanić, Saša and Janaćković, Đorđe",
year = "2006",
abstract = "In this paper the synthesis of bioactive cement based on al-Ca-3(PO4)(2) (a-TCP) and calcium deficient hydroxyapatite (CDHAp), obtained by hydrothermal method from CaCl2, EDTA, NaH(2)PO(4)(.)12H(2)O and urea at 160 degrees C, was described. According to the results of DTA, SEM, X-ray and FTIR analyses performed in this investigation, it is shown that CDHAp is transformed to beta-TCP at 780 degrees C, and to a-TCP at 1400 degrees C. The hardening of the samples, prepared from the mixture of alpha-TCP and 2.5 % solution of Na2HPO4, in simulated body fluid at 37 degrees C, was followed by the microstructure changes.",
publisher = "Trans Tech Publications Ltd, Durnten-Zurich",
journal = "Key Engineering Materials",
title = "Preparation of a-TCP cements from calcium deficient hydroxyapatite obtained by hydrothermal method",
pages = "824-821",
volume = "309-311 II",
doi = "10.4028/0-87849-992-x.821"
}

Jokić, B., Janković-Častvan, I., Veljović, Đ., Petrović, R., Drmanić, S.,& Janaćković, Đ.. (2006). Preparation of a-TCP cements from calcium deficient hydroxyapatite obtained by hydrothermal method. in Key Engineering Materials
Trans Tech Publications Ltd, Durnten-Zurich., 309-311 II, 821-824.
https://doi.org/10.4028/0-87849-992-x.821

Jokić B, Janković-Častvan I, Veljović Đ, Petrović R, Drmanić S, Janaćković Đ. Preparation of a-TCP cements from calcium deficient hydroxyapatite obtained by hydrothermal method. in Key Engineering Materials. 2006;309-311 II:821-824.
doi:10.4028/0-87849-992-x.821 .

Jokić, Bojan, Janković-Častvan, Ivona, Veljović, Đorđe, Petrović, R., Drmanić, Saša, Janaćković, Đorđe, "Preparation of a-TCP cements from calcium deficient hydroxyapatite obtained by hydrothermal method" in Key Engineering Materials, 309-311 II (2006):821-824,
https://doi.org/10.4028/0-87849-992-x.821 . .

TY  - JOUR
AU  - Janaćković, Đorđe
AU  - Janković, Ivana A.
AU  - Petrović, R.
AU  - Kostić-Gvozdenović, Ljiljana
AU  - Milonjić, Slobodan K.
AU  - Uskoković, Dragan
PY  - 2003
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/507
AB  - In this paper surface properties of calcium-hydroxyapatite, synthesized by modified hydrothermal reaction of urea and Ca(EDTA)(2-) in phosphate solutions, as well as the dependence of calcium hydroxyapatite dispersion stability on pH were determined. The specific surface area of calcium-hydroxyapatite was experimentally found to be 67 m(2)/g. The point of zero charge (PZC) of indifferent KCl electrolyte of 6.8 +/- 0.1 was determined by the batch equilibration method. From the dependence of surface charge density on pH and electrolyte concentration, the intrinsic equilibrium constant of surface groups p K-a2(int) was determined to be 8.3 +/- 0.1, while p K-a1(int) calculated from the pK(a2)(int) and point of zero charge values, is 5.3 +/- 0.1. Hydroxyapatite suspension stability was investigated, in the pH range from 7 to 12, it was revealed that the most stable dispersion at pH 10.
PB  - Proceedings of the 15th International Symposium on Ceramics in Medicine; The Annual Meeting of the International Society for Ceramics in Medicine
T2  - Key Engineering Materials
T1  - Surface properties of HAP particles obtained by hydrothermal decomposition of urea and calcium-EDTA chelates
EP  - 440
SP  - 437
VL  - 240-242
UR  - https://hdl.handle.net/21.15107/rcub_technorep_507
ER  - 

@article{
author = "Janaćković, Đorđe and Janković, Ivana A. and Petrović, R. and Kostić-Gvozdenović, Ljiljana and Milonjić, Slobodan K. and Uskoković, Dragan",
year = "2003",
abstract = "In this paper surface properties of calcium-hydroxyapatite, synthesized by modified hydrothermal reaction of urea and Ca(EDTA)(2-) in phosphate solutions, as well as the dependence of calcium hydroxyapatite dispersion stability on pH were determined. The specific surface area of calcium-hydroxyapatite was experimentally found to be 67 m(2)/g. The point of zero charge (PZC) of indifferent KCl electrolyte of 6.8 +/- 0.1 was determined by the batch equilibration method. From the dependence of surface charge density on pH and electrolyte concentration, the intrinsic equilibrium constant of surface groups p K-a2(int) was determined to be 8.3 +/- 0.1, while p K-a1(int) calculated from the pK(a2)(int) and point of zero charge values, is 5.3 +/- 0.1. Hydroxyapatite suspension stability was investigated, in the pH range from 7 to 12, it was revealed that the most stable dispersion at pH 10.",
publisher = "Proceedings of the 15th International Symposium on Ceramics in Medicine; The Annual Meeting of the International Society for Ceramics in Medicine",
journal = "Key Engineering Materials",
title = "Surface properties of HAP particles obtained by hydrothermal decomposition of urea and calcium-EDTA chelates",
pages = "440-437",
volume = "240-242",
url = "https://hdl.handle.net/21.15107/rcub_technorep_507"
}

Janaćković, Đ., Janković, I. A., Petrović, R., Kostić-Gvozdenović, L., Milonjić, S. K.,& Uskoković, D.. (2003). Surface properties of HAP particles obtained by hydrothermal decomposition of urea and calcium-EDTA chelates. in Key Engineering Materials
Proceedings of the 15th International Symposium on Ceramics in Medicine; The Annual Meeting of the International Society for Ceramics in Medicine., 240-242, 437-440.
https://hdl.handle.net/21.15107/rcub_technorep_507

Janaćković Đ, Janković IA, Petrović R, Kostić-Gvozdenović L, Milonjić SK, Uskoković D. Surface properties of HAP particles obtained by hydrothermal decomposition of urea and calcium-EDTA chelates. in Key Engineering Materials. 2003;240-242:437-440.
https://hdl.handle.net/21.15107/rcub_technorep_507 .

Janaćković, Đorđe, Janković, Ivana A., Petrović, R., Kostić-Gvozdenović, Ljiljana, Milonjić, Slobodan K., Uskoković, Dragan, "Surface properties of HAP particles obtained by hydrothermal decomposition of urea and calcium-EDTA chelates" in Key Engineering Materials, 240-242 (2003):437-440,
https://hdl.handle.net/21.15107/rcub_technorep_507 .

TY  - JOUR
AU  - Petrović, R.
AU  - Milonjić, Slobodan K.
AU  - Jokanović, Vukoman
AU  - Kostić-Gvozdenović, Ljiljana
AU  - Petrović-Prelević, I
AU  - Janaćković, Đorđe
PY  - 2003
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/528
AB  - Influence of the type and amount of acid, used for aluminium hydroxide peptization, on the crystallinity and specific surface area of the dispersed phase of boehmite sols as well as the pH of sols, was investigated. The ratio n(HCl)/n(Al(OH)(3))=0.1 was found to be optimum for aluminium hydroxide peptization. Higher acid to aluminium hydroxide ratio leads to a decrease in specific surface area and crystallinity of the solid phase as well as in pH of sols. Increase in counter ion (Cl-) concentration causes a shift in d values of (020) crystallographic plane, from the value corresponding to boehmite to that for pseudoboehmite, and a decrease in specific surface area of the sol solid phase. Using HNO3 as a peptizing agent, greater crystallinity and higher specific surface area values of the solids were registered.
PB  - Elsevier, Amsterdam
T2  - Powder Technology
T1  - Influence of synthesis parameters on the structure of boehmite sol particles
EP  - 189
IS  - 1-3
SP  - 185
VL  - 133
DO  - 10.1016/S0032-5910(03)00091-3
ER  - 

@article{
author = "Petrović, R. and Milonjić, Slobodan K. and Jokanović, Vukoman and Kostić-Gvozdenović, Ljiljana and Petrović-Prelević, I and Janaćković, Đorđe",
year = "2003",
abstract = "Influence of the type and amount of acid, used for aluminium hydroxide peptization, on the crystallinity and specific surface area of the dispersed phase of boehmite sols as well as the pH of sols, was investigated. The ratio n(HCl)/n(Al(OH)(3))=0.1 was found to be optimum for aluminium hydroxide peptization. Higher acid to aluminium hydroxide ratio leads to a decrease in specific surface area and crystallinity of the solid phase as well as in pH of sols. Increase in counter ion (Cl-) concentration causes a shift in d values of (020) crystallographic plane, from the value corresponding to boehmite to that for pseudoboehmite, and a decrease in specific surface area of the sol solid phase. Using HNO3 as a peptizing agent, greater crystallinity and higher specific surface area values of the solids were registered.",
publisher = "Elsevier, Amsterdam",
journal = "Powder Technology",
title = "Influence of synthesis parameters on the structure of boehmite sol particles",
pages = "189-185",
number = "1-3",
volume = "133",
doi = "10.1016/S0032-5910(03)00091-3"
}

Petrović, R., Milonjić, S. K., Jokanović, V., Kostić-Gvozdenović, L., Petrović-Prelević, I.,& Janaćković, Đ.. (2003). Influence of synthesis parameters on the structure of boehmite sol particles. in Powder Technology
Elsevier, Amsterdam., 133(1-3), 185-189.
https://doi.org/10.1016/S0032-5910(03)00091-3

Petrović R, Milonjić SK, Jokanović V, Kostić-Gvozdenović L, Petrović-Prelević I, Janaćković Đ. Influence of synthesis parameters on the structure of boehmite sol particles. in Powder Technology. 2003;133(1-3):185-189.
doi:10.1016/S0032-5910(03)00091-3 .

Petrović, R., Milonjić, Slobodan K., Jokanović, Vukoman, Kostić-Gvozdenović, Ljiljana, Petrović-Prelević, I, Janaćković, Đorđe, "Influence of synthesis parameters on the structure of boehmite sol particles" in Powder Technology, 133, no. 1-3 (2003):185-189,
https://doi.org/10.1016/S0032-5910(03)00091-3 . .

TY  - JOUR
AU  - Petrović, R.
AU  - Janaćković, Đorđe
AU  - Zec, Slavica
AU  - Drmanić, Saša
AU  - Kostić-Gvozdenović, Ljiljana
PY  - 2003
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/532
AB  - Alkoxy-derived cordierite gels were synthesized from tetraethylorthosilicate (TEOS), aluminum isopropoxide (Al(OPri)(3)), and magnesium ethoxide (Mg(OEt)(2)). TEOS was partially hydrolyzed at molar ratios H2O/TEOS=1.2, in the presence of hydrochloric acid as a catalyst, HCl/TEOS=0.1. Aluminum and magnesium alkoxides were added successively or as a double alkoxide. Phase transformations occurring in the gel were studied by differential thermal analysis, x-ray diffractometry, and Fourier-transform infrared spectroscopy. In all cases, mu-cordierite crystallized at similar temperatures (950-1000degreesC) with small amounts of spinel, which confirms dominant influence of the optimal conditions for partial hydrolysis of TEOS on the gels homogeneity. The transformation of mu- into alpha-cordierite began at about 1100degreesC. Broadening of diffraction peaks and appearance of new bands in the FT IR spectra confirmed the transformation of alpha- into modulated beta-cordierite at temperatures above 1300degreesC. Differential thermal analysis under nonisothermal conditions also proved homogeneous nucleation with constant rate and three-dimensional crystallite growth during mu-cordierite crystallization. The overall activation energy of the crystallization of mu-cordierite is 580+/-81 kJ/mol.
PB  - Springer, New York
T2  - Journal of Sol-Gel Science and Technology
T1  - Crystallization behavior of alkoxy-derived cordierite gels
EP  - 118
IS  - 1
SP  - 111
VL  - 28
DO  - 10.1023/A:1025649406466
ER  - 

@article{
author = "Petrović, R. and Janaćković, Đorđe and Zec, Slavica and Drmanić, Saša and Kostić-Gvozdenović, Ljiljana",
year = "2003",
abstract = "Alkoxy-derived cordierite gels were synthesized from tetraethylorthosilicate (TEOS), aluminum isopropoxide (Al(OPri)(3)), and magnesium ethoxide (Mg(OEt)(2)). TEOS was partially hydrolyzed at molar ratios H2O/TEOS=1.2, in the presence of hydrochloric acid as a catalyst, HCl/TEOS=0.1. Aluminum and magnesium alkoxides were added successively or as a double alkoxide. Phase transformations occurring in the gel were studied by differential thermal analysis, x-ray diffractometry, and Fourier-transform infrared spectroscopy. In all cases, mu-cordierite crystallized at similar temperatures (950-1000degreesC) with small amounts of spinel, which confirms dominant influence of the optimal conditions for partial hydrolysis of TEOS on the gels homogeneity. The transformation of mu- into alpha-cordierite began at about 1100degreesC. Broadening of diffraction peaks and appearance of new bands in the FT IR spectra confirmed the transformation of alpha- into modulated beta-cordierite at temperatures above 1300degreesC. Differential thermal analysis under nonisothermal conditions also proved homogeneous nucleation with constant rate and three-dimensional crystallite growth during mu-cordierite crystallization. The overall activation energy of the crystallization of mu-cordierite is 580+/-81 kJ/mol.",
publisher = "Springer, New York",
journal = "Journal of Sol-Gel Science and Technology",
title = "Crystallization behavior of alkoxy-derived cordierite gels",
pages = "118-111",
number = "1",
volume = "28",
doi = "10.1023/A:1025649406466"
}

Petrović, R., Janaćković, Đ., Zec, S., Drmanić, S.,& Kostić-Gvozdenović, L.. (2003). Crystallization behavior of alkoxy-derived cordierite gels. in Journal of Sol-Gel Science and Technology
Springer, New York., 28(1), 111-118.
https://doi.org/10.1023/A:1025649406466

Petrović R, Janaćković Đ, Zec S, Drmanić S, Kostić-Gvozdenović L. Crystallization behavior of alkoxy-derived cordierite gels. in Journal of Sol-Gel Science and Technology. 2003;28(1):111-118.
doi:10.1023/A:1025649406466 .

Petrović, R., Janaćković, Đorđe, Zec, Slavica, Drmanić, Saša, Kostić-Gvozdenović, Ljiljana, "Crystallization behavior of alkoxy-derived cordierite gels" in Journal of Sol-Gel Science and Technology, 28, no. 1 (2003):111-118,
https://doi.org/10.1023/A:1025649406466 . .

TY  - JOUR
AU  - Janaćković, Đorđe
AU  - Petrović-Prelević, I
AU  - Kostić-Gvozdenović, Ljiljana
AU  - Petrović, R.
AU  - Jokanović, Vukoman
AU  - Uskoković, Dragan
PY  - 2001
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/346
AB  - In this paper the synthesis of biocompatible calcium-hydroxyapatite particles, chemically and morphologically similar to the mineral particles in human bones, is presented. The influence of synthesis parameters: temperature, pH, concentrations of solution and time on the particle size and morphology of nanostructured Ca-hydroxyapatite were investigated. The obtained results show that in the temperature range between 125 to 160 degreesC the particle sizes decreased from 31.7 to 25.2 nm in the 001 plane, but increased at 180 degreesC to 45 nm, while in h00 planes they increased from 15.8 to 26.2 nm with the temperature rising. The changes in pH values of solution do not have a great influence on crystallite size. In the samples where the concentration of starting solutions is increased, the enlargement in particle sizes from 25.2 to 46.7 nm in the 001 planes is observed, while in the h00 planes, particle sizes are changed sligthtly. It was found that the prolonged time of the reaction has a great influence on crystallite size leading to the increase in the size in the 001 plane. The changes in the crystal cell parameters a and c and FTIR analysis, due to variations of synthesis parameters, can be a consequence of the CO32- ions incorporated into the crystal structure of hydroxyapatite.
PB  - 13th international Symposium on Ceramics in Medicine (BIOCERAMICS)
T2  - Key Engineering Materials
T1  - Influence of synthesis parameters on the particle sizes of nanostructured calcium-hydroxyapatite
EP  - 206
SP  - 203
VL  - 192-195
UR  - https://hdl.handle.net/21.15107/rcub_technorep_346
ER  - 

@article{
author = "Janaćković, Đorđe and Petrović-Prelević, I and Kostić-Gvozdenović, Ljiljana and Petrović, R. and Jokanović, Vukoman and Uskoković, Dragan",
year = "2001",
abstract = "In this paper the synthesis of biocompatible calcium-hydroxyapatite particles, chemically and morphologically similar to the mineral particles in human bones, is presented. The influence of synthesis parameters: temperature, pH, concentrations of solution and time on the particle size and morphology of nanostructured Ca-hydroxyapatite were investigated. The obtained results show that in the temperature range between 125 to 160 degreesC the particle sizes decreased from 31.7 to 25.2 nm in the 001 plane, but increased at 180 degreesC to 45 nm, while in h00 planes they increased from 15.8 to 26.2 nm with the temperature rising. The changes in pH values of solution do not have a great influence on crystallite size. In the samples where the concentration of starting solutions is increased, the enlargement in particle sizes from 25.2 to 46.7 nm in the 001 planes is observed, while in the h00 planes, particle sizes are changed sligthtly. It was found that the prolonged time of the reaction has a great influence on crystallite size leading to the increase in the size in the 001 plane. The changes in the crystal cell parameters a and c and FTIR analysis, due to variations of synthesis parameters, can be a consequence of the CO32- ions incorporated into the crystal structure of hydroxyapatite.",
publisher = "13th international Symposium on Ceramics in Medicine (BIOCERAMICS)",
journal = "Key Engineering Materials",
title = "Influence of synthesis parameters on the particle sizes of nanostructured calcium-hydroxyapatite",
pages = "206-203",
volume = "192-195",
url = "https://hdl.handle.net/21.15107/rcub_technorep_346"
}

Janaćković, Đ., Petrović-Prelević, I., Kostić-Gvozdenović, L., Petrović, R., Jokanović, V.,& Uskoković, D.. (2001). Influence of synthesis parameters on the particle sizes of nanostructured calcium-hydroxyapatite. in Key Engineering Materials
13th international Symposium on Ceramics in Medicine (BIOCERAMICS)., 192-195, 203-206.
https://hdl.handle.net/21.15107/rcub_technorep_346

Janaćković Đ, Petrović-Prelević I, Kostić-Gvozdenović L, Petrović R, Jokanović V, Uskoković D. Influence of synthesis parameters on the particle sizes of nanostructured calcium-hydroxyapatite. in Key Engineering Materials. 2001;192-195:203-206.
https://hdl.handle.net/21.15107/rcub_technorep_346 .

Janaćković, Đorđe, Petrović-Prelević, I, Kostić-Gvozdenović, Ljiljana, Petrović, R., Jokanović, Vukoman, Uskoković, Dragan, "Influence of synthesis parameters on the particle sizes of nanostructured calcium-hydroxyapatite" in Key Engineering Materials, 192-195 (2001):203-206,
https://hdl.handle.net/21.15107/rcub_technorep_346 .

TY  - JOUR
AU  - Petrović, R.
AU  - Janaćković, Đorđe
AU  - Zec, Slavica
AU  - Drmanić, Saša
AU  - Kostić-Gvozdenović, Ljiljana
PY  - 2001
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/353
AB  - A triphasic cordierite-type gel was prepared from silica sol, boehmite sol, and an aqueous solution of Mg(NO3)(2). 6H(2)O. The silica sol was obtained from water glass by the ion exchange method, while boehmite sol was obtained by peptization of freshly prepared Al(OH)(3), Phase transformations occurring in the get were studied by differential scanning calorimetry, x-ray diffractometry, and Fourier transform infrared spectrometry. Spinel was observed to crystallize from the gel prior to cristobalite; their reaction subsequently yielded alpha -cordierite, At higher temperatures, alpha -cordierite transformed into modulated beta -cordierite. Kinetic parameters of alpha -cordierite formation and alpha -cordierite to modulated beta -cordierite transformation were determined by differential scanning calorimetry under nonisothermal conditions. Formation of alpha -cordierite was found to be a diffusion-controlled process. with an overall activation energy Of E-a = 1232 +/- 66 kJ/mol. During the alpha -- gt  beta -cordierite transformation, a modulated phase was formed by surface transformation of alpha -cordierite, The overall activation energy for the formation of the modulated structure is E-a = 583 +/- 77 kJ/mol.
PB  - Cambridge Univ Press, New York
T2  - Journal of Materials Research
T1  - Phase-transformation kinetics in triphasic cordierite gel
EP  - 458
IS  - 2
SP  - 451
VL  - 16
DO  - 10.1557/JMR.2001.0068
ER  - 

@article{
author = "Petrović, R. and Janaćković, Đorđe and Zec, Slavica and Drmanić, Saša and Kostić-Gvozdenović, Ljiljana",
year = "2001",
abstract = "A triphasic cordierite-type gel was prepared from silica sol, boehmite sol, and an aqueous solution of Mg(NO3)(2). 6H(2)O. The silica sol was obtained from water glass by the ion exchange method, while boehmite sol was obtained by peptization of freshly prepared Al(OH)(3), Phase transformations occurring in the get were studied by differential scanning calorimetry, x-ray diffractometry, and Fourier transform infrared spectrometry. Spinel was observed to crystallize from the gel prior to cristobalite; their reaction subsequently yielded alpha -cordierite, At higher temperatures, alpha -cordierite transformed into modulated beta -cordierite. Kinetic parameters of alpha -cordierite formation and alpha -cordierite to modulated beta -cordierite transformation were determined by differential scanning calorimetry under nonisothermal conditions. Formation of alpha -cordierite was found to be a diffusion-controlled process. with an overall activation energy Of E-a = 1232 +/- 66 kJ/mol. During the alpha -- gt  beta -cordierite transformation, a modulated phase was formed by surface transformation of alpha -cordierite, The overall activation energy for the formation of the modulated structure is E-a = 583 +/- 77 kJ/mol.",
publisher = "Cambridge Univ Press, New York",
journal = "Journal of Materials Research",
title = "Phase-transformation kinetics in triphasic cordierite gel",
pages = "458-451",
number = "2",
volume = "16",
doi = "10.1557/JMR.2001.0068"
}

Petrović, R., Janaćković, Đ., Zec, S., Drmanić, S.,& Kostić-Gvozdenović, L.. (2001). Phase-transformation kinetics in triphasic cordierite gel. in Journal of Materials Research
Cambridge Univ Press, New York., 16(2), 451-458.
https://doi.org/10.1557/JMR.2001.0068

Petrović R, Janaćković Đ, Zec S, Drmanić S, Kostić-Gvozdenović L. Phase-transformation kinetics in triphasic cordierite gel. in Journal of Materials Research. 2001;16(2):451-458.
doi:10.1557/JMR.2001.0068 .

Petrović, R., Janaćković, Đorđe, Zec, Slavica, Drmanić, Saša, Kostić-Gvozdenović, Ljiljana, "Phase-transformation kinetics in triphasic cordierite gel" in Journal of Materials Research, 16, no. 2 (2001):451-458,
https://doi.org/10.1557/JMR.2001.0068 . .