Production and Characterization of Hydroxyapatite/Niobo Phosphate Glass Scaffold

2013 ◽  
Vol 587 ◽  
pp. 128-131 ◽  
Author(s):  
Daniel Navarro da Rocha ◽  
Leila Rosa de Oliveira Cruz ◽  
João Luiz do Prado Neto ◽  
Nadia Mohammed Elmassalami Ayad ◽  
Luciano de Andrade Gobbo ◽  
...  

The present study concerns the production and characterization of porous hydroxyapatite/niobo-phosphate glass ceramics to be used for bone repair. The scaffolds were produced by hydrothermal deposition of monetite on polyurethane sponge substrates, further converted to hydroxyapatite in an alkali solution. After heat treatment, elimination of the organic sponge provides a three-dimensional (3D) structure. Niobo-phosphate glasses were added to the heat treated struts and the scaffolds were sintered. The porous bodies were characterized by field-emission gun scanning electron microscope (FEG-SEM) with energy-dispersive X-ray spectroscopy (EDS).

Crystals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 109
Author(s):  
Haijian Li ◽  
Hao Zou ◽  
Zhihua Sun ◽  
Yi Xu ◽  
Changjian Wang ◽  
...  

The composition, structure, and thermal behaviors of yttrium-containing phosphate glasses were studied in this work, and the glass-ceramics were prepared via the two-step crystallization method. The XRD and SEM-EDS results show the forming range of the phosphate glass system and the formation of YPO4 (xenotime) due to the addition of excessive Y2O3. The spectroscopic characterization of these glasses presented shifts of the infrared and Raman bands, demonstrating the depolymerization of the glass network and the formation of novel P–O–Y bonds, and the deconvoluted Raman spectra also exhibited the occurrence of the disproportionation reaction in the glass melting process. The content of non-bridging oxygen (NBOs) from the UV–vis spectra first increased and then decreased with increasing Y2O3. The thermal behaviors show that the Y2O3 reduced the crystallization peak temperature and the thermal stability of the glasses. The crystalline behaviors of the phosphate glass matrix were investigated at different crystallization times of 2–10 h, and a transformation of the crystallization mechanism from surface to volume crystallization was found. The yttrium phosphate glass-ceramics crystallized for 10 h exhibited transformation of the main crystalline phases with increasing Y2O3, and the grain-oriented crystalline surface became irregular.


Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 259
Author(s):  
Natalia Pawlik ◽  
Barbara Szpikowska-Sroka ◽  
Tomasz Goryczka ◽  
Ewa Pietrasik ◽  
Wojciech A. Pisarski

The synthesis and characterization of multicolor light-emitting nanomaterials based on rare earths (RE3+) are of great importance due to their possible use in optoelectronic devices, such as LEDs or displays. In the present work, oxyfluoride glass-ceramics containing BaF2 nanocrystals co-doped with Tb3+, Eu3+ ions were fabricated from amorphous xerogels at 350 °C. The analysis of the thermal behavior of fabricated xerogels was performed using TG/DSC measurements (thermogravimetry (TG), differential scanning calorimetry (DSC)). The crystallization of BaF2 phase at the nanoscale was confirmed by X-ray diffraction (XRD) measurements and transmission electron microscopy (TEM), and the changes in silicate sol–gel host were determined by attenuated total reflectance infrared (ATR-IR) spectroscopy. The luminescent characterization of prepared sol–gel materials was carried out by excitation and emission spectra along with decay analysis from the 5D4 level of Tb3+. As a result, the visible light according to the electronic transitions of Tb3+ (5D4 → 7FJ (J = 6–3)) and Eu3+ (5D0 → 7FJ (J = 0–4)) was recorded. It was also observed that co-doping with Eu3+ caused the shortening in decay times of the 5D4 state from 1.11 ms to 0.88 ms (for xerogels) and from 6.56 ms to 4.06 ms (for glass-ceramics). Thus, based on lifetime values, the Tb3+/Eu3+ energy transfer (ET) efficiencies were estimated to be almost 21% for xerogels and 38% for nano-glass-ceramics. Therefore, such materials could be successfully predisposed for laser technologies, spectral converters, and three-dimensional displays.


Author(s):  
Anatoly Frenkel

We discuss methods of Extended X-ray Absorption Fine-Structure (EXAFS) analysis that provide three-dimensional structural characterization of metal nanoparticles, both mono- and bi-metallic. For the bimetallic alloys, we use short range order measurements to discriminate between random and non-random inter-particle distributions of atoms. We also discuss the application of EXAFS to heterogeneous nanoparticle systems.


2006 ◽  
Vol 932 ◽  
Author(s):  
Paul A. Bingham ◽  
Russell J. Hand ◽  
Charlie R. Scales

ABSTRACTVitrification is a potential route for the immobilisation of Plutonium Contaminated Material (PCM). This is an Intermediate Level Waste (ILW) arising from operations in which there is contact with Pu isotopes. PCM consists of low levels of Pu combined with metals, masonry, glass, ceramics, polymers and other carbonaceous materials. Simulated PCM containing CeO2 as a PuO2 surrogate was mixed with a phosphate precursor and vitrified. Pre-oxidation of PCM simulant prior to vitrification minimised the violence of batch reactions. No pre-oxidation produced inhomogeneous slag-like materials with high residual metals and particulates. Pre-oxidation at 600°C in air and at 1200°C in an O2-rich atmosphere produced more favourable results, with increasingly vitreous products resulting from more oxidised PCM simulant. The most oxidised PCM simulant produced phosphate glasses with low levels of particulate inclusions, as confirmed by x-ray diffraction and scanning electron microscopy. Particulates included iron-rich metallics and aluminous oxides. Increased melting times and temperatures may have reduced the number of inclusions slightly, but O2 bubbling during melting resulted in little additional benefit. Waste loading equivalent to ∼60 weight % of untreated waste may be possible. There was little evidence of Ce partitioning, indicating that it was immobilised within the glass matrix and had little preference for metallic or crystalline phases. These results demonstrate the potential feasibility for vitrification of PCM in phosphate glass, justifying further investigation into this potentially novel solution.


2014 ◽  
Vol 20 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Tae Wan Kim ◽  
Su Chak Ryu ◽  
Byung Kyu Kim ◽  
Seog Young Yoon ◽  
Hong Chae Park

2012 ◽  
Vol 557-559 ◽  
pp. 1612-1617
Author(s):  
Jian An Liu ◽  
Xue Na Yang ◽  
Mei Mei Zhang ◽  
Wen He

The ferrimagnetic glass-ceramic based on SrO-Na2O-Fe2O3-FeO-P2O5-SiO2 system was prepared for hyperthermia application using aqueous aolution-melt method. Using the aqueous solution solvent evaporation, we obtained the molecular-scale homogenously glass precursor. The precursor was completely melted in a lidded platinum crucible placed in an electric furnace at 1480°C for 1h and then annealed in a furnace at 550°C for 40min.The annealed glasses were heat treated at 1050°C for 1h to obtain the glass-ceramics. The crystallization of the glass systems with different component has been systematically investigated by using XRD, TEM, as well as vibrating sample magnetometer (VSM). The glass-ceramics with P2O5=5.0wt% show a strong magnetic, which contains highest value of specific saturation magnetization of 24.89A•m2/kg.


2012 ◽  
Vol 581-582 ◽  
pp. 457-462
Author(s):  
Jian An Liu ◽  
Xue Na Yang ◽  
Mei Mei Zhang ◽  
Wen He

The ferrimagnetic glass-ceramic based on SrO-Na2O-Fe2O3-P2O5-SiO2 system was prepared for hyperthermia application using aqueous aolution-melt method. Using the aqueous solution solvent evaporation, we obtained the molecular-scale homogenously glass precursor. The precursor was completely melted in a lidded platinum crucible placed in an electric furnace at 1480°C for 1h and then annealed in a furnace at 550°C for 40min.The annealed glasses were heat treated at 1050°C for 2h to obtain the glass-ceramics. The crystallization of the glass systems with different component has been systematically investigated by using XRD. Room temperature magnetic property of the samples were investigated using a Vibrating Sample Magnetometer(VSM). The evolution of magnetic properties in these glasses as a function of P2O5 quality concentration was discussed.


RSC Advances ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 1822-1830
Author(s):  
Martin Mangstl ◽  
Jan Konrad Wied ◽  
Johannes Weber ◽  
Christian Pritzel ◽  
Reinhard Trettin ◽  
...  

The novel glass shows the lowest glass transition temperature known for binary phosphate glass systems without acidic protons.


2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Gerardo Cristian Scarpignato ◽  
Daniel Milanese ◽  
Joris Lousteau ◽  
Nadia Giovanna Boetti ◽  
Emanuele Mura

We present the fabrication and characterization of a short core pumped fiber amplifier made of Yb3+-Er3+codoped phosphate glasses. The 27 mm long amplifier provides a maximum internal gain of 10.7 dB for a signal of −30 dBm at 1535 nm with a 479 mW pump power operating at 975.6 nm. This leads to a gain of 4.0 dB/cm, which compares favorably to other recent works.


2008 ◽  
Vol 63 (2) ◽  
pp. 187-192 ◽  
Author(s):  
Chun-jing Zhang ◽  
Ya-guang Chen ◽  
Dong-mei Shi ◽  
Hai-jun Pang

A novel transition metal polyoxotungstate, [Cu(H2O)6][{Cu(H2O)2}2{Cu(H2O)4H4W12O42}] · 12H2O (1), has been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction, elemental analysis, IR and UV/vis spectroscopy, and TG analysis. The paradodecatungstate anions [H2W12O42]10− are linked by CuO6 octahedra, forming a three-dimensional (3D) structure. The magnetic susceptibility of compound 1 in the temperature range 2 - 300 K shows the presence of antiferromagnetic interactions within the uniform Cu2・ ・ ・Cu3 chains


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