The Hydrothermal Synthesis Duration Influence on Calcium Phosphate and Hydroxyapatite Phase Composition

This paper reports the hydrothermal synthesis process duration influence on phase composition, crystallinity degree, morphology and dispersity of the hydroxyapatite powder. The calcium phosphate and hydroxyapatite were synthesized in precursor system Ca(NO[3])[2](NH[4])[2]HPO[4]-NH[4]OH. The obtained powders were characterized with X-Ray diffraction, Fourier Transform spectroscopy (FTIR) and Raman spectroscopy. The results demonstrate: the increasing of the synthesis time duration has no influence on the phase composition. However, the synthesis duration time growth from 12 to 48 hours make possible increase the crystallinity degree from 0.68 to 0.98

The Hydrothermal Synthesis Duration Influence on Calcium Phosphate and Hydroxyapatite Phase Composition

This paper reports the hydrothermal synthesis process duration influence on phase composition, crystallinity degree, morphology and dispersity of the hydroxyapatite powder. The calcium phosphate and hydroxyapatite were synthesized in precursor system Ca(NO[3])[2](NH[4])[2]HPO[4]-NH[4]OH. The obtained powders were characterized with X-Ray diffraction, Fourier Transform spectroscopy (FTIR) and Raman spectroscopy. The results demonstrate: the increasing of the synthesis time duration has no influence on the phase composition. However, the synthesis duration time growth from 12 to 48 hours make possible increase the crystallinity degree from 0.68 to 0.98

The pH Level Influence on Hydroxyapatite Phase Composition Synthesized with Hydrothermal Method

This paper reports the pH level influence on hydroxyapatite phase composition synthesized with hydrothermal method in Ca(OH)2-H3PO4, Ca(NO3)2-(NH4)2HPO4-NH[4]OH, Ca(OH)[2]-NH[4]H[2]PO[4].The obtained samples were studied with X-Ray diffraction, Fourier Transform Infrared (FTIR) and Raman spectroscopy. The one phase Ca[5]H[2]O[13]P[3] high crystallinity hydroxyapatite was synthesized with hydrothermal method at pH equal to 11. The crystallinity degree was calculated from the X-Ray diffraction pattern and became 0.96. The increasing pH level from 7 to 11 provides obtaining one phase hydroxyapatite at pH level 11 instead the two phase Ca[9.04](PO[4])6(OH)[1.68], CaHPO[4] at pH level 9 and CaPO[3](OH), Ca(OH)[2] at pH level 7

The pH Level Influence on Hydroxyapatite Phase Composition Synthesized with Hydrothermal Method

This paper reports the pH level influence on hydroxyapatite phase composition synthesized with hydrothermal method in Ca(OH)2-H3PO4, Ca(NO3)2-(NH4)2HPO4-NH[4]OH, Ca(OH)[2]-NH[4]H[2]PO[4].The obtained samples were studied with X-Ray diffraction, Fourier Transform Infrared (FTIR) and Raman spectroscopy. The one phase Ca[5]H[2]O[13]P[3] high crystallinity hydroxyapatite was synthesized with hydrothermal method at pH equal to 11. The crystallinity degree was calculated from the X-Ray diffraction pattern and became 0.96. The increasing pH level from 7 to 11 provides obtaining one phase hydroxyapatite at pH level 11 instead the two phase Ca[9.04](PO[4])6(OH)[1.68], CaHPO[4] at pH level 9 and CaPO[3](OH), Ca(OH)[2] at pH level 7

Microwave treatment and pH influence on hydroxyapatite morphology and structure

This paper reports the influence of microwave treatment duration and pH conditions of initial precursors on the morphological and crystalline dispersity of the hydroxyapatite (HAp) synthesized by hydrothermal method.The obtained HAp samples were studied by scanning electron microscopy, X-Ray diffraction method and low nitrogen adsorption method. We have obtained nanostructured crystalline hydroxyapatite with 95% crystallinity, porous structure and average particles size in interval 17...46 nm consolidated in aggregates with size distribution of 0.5...25 [mu]m. The pH growth from 8 to 13 results in double increase of HAp specific area(from 69 up to 133 m{2}/g), meanwhile microwave irradiation brings to particles aggregation: HAp treated during 0... 10...30 min have specific surface are 112...67...41 m{2}/g, respectively. As a result at pH=13 and without microwave irradiation treatment we synthesized HAp with maximum surface compared to the surface of natural HAp that makes obtained HApto be promising material in biotechnological applications