TY  - CONF
AU  - Sokić, Katarina
AU  - Veljović, Đorđe
AU  - Dikić, Jelena
AU  - Stojanović, Jovica
AU  - Smiljanić, Danijela
AU  - Jevtić, Sanja
PY  - 2021
UR  - https://ritnms.itnms.ac.rs/handle/123456789/728
AB  - The aim of this study was to investigate the possibilities and to optimize the conditions for the synthesis of hydroxyapatite (HAP) on calcium-enriched natural and synthetic zeolites as carriers. Two synthetic zeolites were used in the paper: zeolite 4A (Na-form) and zeolite 5A (Ca-form) as well as natural zeolite - clinoptilolite from Slanci deposit in Serbia.
Clinoptilolite and zeolite 4A were enriched with calcium ions by ion exchange treatmentin order to enable the source of Ca2+in the crystallization of hydroxyapatite. Phosphorus, necessary for the crystallization of hydroxyapatite, was introduced through a solution of ammonium-hydrogenphosphate. The influence of the concentration of hydrogen phosphate ions, temperature and crystallization time of hydroxyapatite on the morphology of the zeolite surface as well as the degree of its coverage with newly formed hydroxyapatite particles was monitored in the experiments. The obtained powders were characterized by X-ray powder diffraction (XRD), thermal TG-DTG analysis, infrared spectroscopy with Fourier transformation (FTIR) and scanning electron microscopy (SEM). Based on the structural analysis, it was shown that the synthesis of hydroxyapatite did not affect on the structure of the zeolite, except in the case when a very concentrated hydrogen-phosphate solution was used. Thermal analysis showed that all obtained zeolite and HAP samples were stable up to 800 °C. Optimization of the hydrothermal crystallization process showed that temperature and time do not have a crucial influence on the synthesis of the materials (similar results were obtained at 120 °C for 20 hours and at 160 °C for 4 hours). When the concentration of the solution of ammonium hydrogen phosphate was higher, larger crystals of hydroxyapatite were obtained, but the crystal lattice of the zeolite was collapsed. SEM micrography showed that unevenly distributed hydroxyapatite crystals were formed on natural zeolite due to the presence of various impurities, while the best results were achieved using zeolite 5A, where
the surface of the zeolite is completely covered with crystals of hydroxyapatite.
PB  - Belgrade : Institute of Technical Sciences of SASA
C3  - Nineteenth Young Researchers’ Conference - Materials Science and Engineering
T1  - Hydrothermal synthesis of hydroxyapatite on calcium-enriched natural and synthetic zeolite as a carrier
EP  - 75
SP  - 75
ER  - 

@conference{
author = "Sokić, Katarina and Veljović, Đorđe and Dikić, Jelena and Stojanović, Jovica and Smiljanić, Danijela and Jevtić, Sanja",
year = "2021",
abstract = "The aim of this study was to investigate the possibilities and to optimize the conditions for the synthesis of hydroxyapatite (HAP) on calcium-enriched natural and synthetic zeolites as carriers. Two synthetic zeolites were used in the paper: zeolite 4A (Na-form) and zeolite 5A (Ca-form) as well as natural zeolite - clinoptilolite from Slanci deposit in Serbia.
Clinoptilolite and zeolite 4A were enriched with calcium ions by ion exchange treatmentin order to enable the source of Ca2+in the crystallization of hydroxyapatite. Phosphorus, necessary for the crystallization of hydroxyapatite, was introduced through a solution of ammonium-hydrogenphosphate. The influence of the concentration of hydrogen phosphate ions, temperature and crystallization time of hydroxyapatite on the morphology of the zeolite surface as well as the degree of its coverage with newly formed hydroxyapatite particles was monitored in the experiments. The obtained powders were characterized by X-ray powder diffraction (XRD), thermal TG-DTG analysis, infrared spectroscopy with Fourier transformation (FTIR) and scanning electron microscopy (SEM). Based on the structural analysis, it was shown that the synthesis of hydroxyapatite did not affect on the structure of the zeolite, except in the case when a very concentrated hydrogen-phosphate solution was used. Thermal analysis showed that all obtained zeolite and HAP samples were stable up to 800 °C. Optimization of the hydrothermal crystallization process showed that temperature and time do not have a crucial influence on the synthesis of the materials (similar results were obtained at 120 °C for 20 hours and at 160 °C for 4 hours). When the concentration of the solution of ammonium hydrogen phosphate was higher, larger crystals of hydroxyapatite were obtained, but the crystal lattice of the zeolite was collapsed. SEM micrography showed that unevenly distributed hydroxyapatite crystals were formed on natural zeolite due to the presence of various impurities, while the best results were achieved using zeolite 5A, where
the surface of the zeolite is completely covered with crystals of hydroxyapatite.",
publisher = "Belgrade : Institute of Technical Sciences of SASA",
journal = "Nineteenth Young Researchers’ Conference - Materials Science and Engineering",
title = "Hydrothermal synthesis of hydroxyapatite on calcium-enriched natural and synthetic zeolite as a carrier",
pages = "75-75"
}

Sokić, K., Veljović, Đ., Dikić, J., Stojanović, J., Smiljanić, D.,& Jevtić, S.. (2021). Hydrothermal synthesis of hydroxyapatite on calcium-enriched natural and synthetic zeolite as a carrier. in Nineteenth Young Researchers’ Conference - Materials Science and Engineering
Belgrade : Institute of Technical Sciences of SASA., 75-75.

Sokić K, Veljović Đ, Dikić J, Stojanović J, Smiljanić D, Jevtić S. Hydrothermal synthesis of hydroxyapatite on calcium-enriched natural and synthetic zeolite as a carrier. in Nineteenth Young Researchers’ Conference - Materials Science and Engineering. 2021;:75-75..

Sokić, Katarina, Veljović, Đorđe, Dikić, Jelena, Stojanović, Jovica, Smiljanić, Danijela, Jevtić, Sanja, "Hydrothermal synthesis of hydroxyapatite on calcium-enriched natural and synthetic zeolite as a carrier" in Nineteenth Young Researchers’ Conference - Materials Science and Engineering (2021):75-75.