Processing and Properties of Biphasic Calcium Phosphates Bioceramics Derived from Biowaste Materials

2018 ◽  
Vol 777 ◽  
pp. 602-606
Author(s):  
Narumon Lertcumfu ◽  
Phurin Netthip ◽  
Pharatree Jaita ◽  
Supalak Manotham
Keyword(s):  
Solid State ◽  
Calcium Phosphate ◽  
Thermal Treatment ◽  
Sintering Temperature ◽  
Calcium Phosphates ◽  
Bovine Bone ◽  
X Ray ◽  
Grain Sizes ◽  
Maximum Value ◽  
Mussel Shells

Properties of biphasic calcium phosphates bioceramics derived from biowaste materials were investigated. The hydroxyapatite (HA) powder was synthesized from bovine bone via thermal treatment while β-tricalcium phosphate (β-TCP) powder was synthesized from mussel shells via solid state solution. Pure HA and β-TCP were successful obtained. The HA and β-TCP were mixed together and sintered at 1100 - 1350°C. The effects of the sintering temperature and the ratio of HA/ β-TCP on the properties of the studied samples were investigated. The sintering temperature at 1250°C presented the maximum value of density and hardness. X-ray analysis of BCP ceramics sintered at 1250°C presented multiple phases of calcium phosphate. Average grain sizes of the studied samples decreased as the ratio of HA increased.

scholarly journals Integrated 3D Information for Custom-Made Bone Grafts: Focus on Biphasic Calcium Phosphate Bone Substitute Biomaterials

2020 ◽  
Vol 17 (14) ◽  
pp. 4931
Author(s):  
Alessandra Giuliani ◽  
Maria Laura Gatto ◽  
Luigi Gobbi ◽  
Francesco Guido Mangano ◽  
Carlo Mangano
Keyword(s):  
Calcium Phosphate ◽  
Biphasic Calcium Phosphate ◽  
Alveolar Bone ◽  
Sintering Temperature ◽  
Calcium Phosphates ◽  
Compressive Loading ◽  
Peak Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Custom Made

Purpose: Several studies showed that the sintering temperature of 1250 °C could affect the formation of α-Ca3(PO4)2, which is responsible for the reduction of the hardness value of biphasic calcium phosphate biocomposites, but they did not evaluate the inference of the sintering time at peak temperature on transition of β-Ca3(PO4)2 to α-Ca3(PO4)2. This analysis explored, in an innovative way, inferences and correlations between volumetric microstructure, mechanical properties, sintering temperature, and time at peak temperature in order to find the best sintering conditions for biphasic calcium phosphate composites grafted in severe alveolar bone defects. Methods: Sintered biphasic calcium phosphates (30%-hydroxyapatite/70%-tricalcium phosphate) were tested by microCT imaging for the 3D morphometric analysis, by compressive loading to find their mechanical parameters, and by X-ray diffraction to quantify the phases via Rietveld refinement for different sintering temperatures and times at the peak temperature. Data were analysed in terms of statistical inference using Pearson’s correlation coefficients. Results: All the studied scaffolds closely mimicked the alveolar organization of the jawbone, independently on the sintering temperatures and times; however, mechanical testing revealed that the group with peak temperature, which lasted for 2 hours at 1250 °C, showed the highest strength both at the ultimate point and at fracture point. Conclusion: The good mechanical performances of the group with peak temperature, which lasted for 2 hours at 1250 °C, is most likely due to the absence of the α-Ca3(PO4)2 phase, as revealed by X-ray diffraction. However, we detected its presence after sintering at the same peak temperature for longer times, showing the time-dependence, combined with the temperature-dependence, of the β-Ca3(PO4)2 to α-Ca3(PO4)2 transition.

scholarly journals Synthesis and Na+ Ion Conductivity of Stoichiometric Na3Zr2Si2PO12 by Liquid-Phase Sintering with NaPO3 Glass

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3790
Author(s):  
Yongzheng Ji ◽  
Tsuyoshi Honma ◽  
Takayuki Komatsu
Keyword(s):  
Solid State ◽  
Liquid Phase ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Ion Conductivity ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Sintering Time ◽  
Lower Activation

Sodium super ionic conductor (NASICON)-type Na3Zr2Si2PO12 (NZSP) with the advantages of the high ionic conductivity, stability and safety is one of the most famous solid-state electrolytes. NZSP, however, requires the high sintering temperature about 1200 °C and long sintering time in the conventional solid-state reaction (SSR) method. In this study, the liquid-phase sintering (LPS) method was applied to synthesize NZSP with the use of NaPO3 glass with a low glass transition temperature of 292 °C. The formation of NZSP was confirmed by X-ray diffraction analyses in the samples obtained by the LPS method for the mixture of Na2ZrSi2O7, ZrO2, and NaPO3 glass. The sample sintered at 1000 °C for 10 h exhibited a higher Na+ ion conductivity of 1.81 mS/cm at 100 °C and a lower activation energy of 0.18 eV compared with the samples prepared by the SSR method. It is proposed that a new LPE method is effective for the synthesis of NZSP and the NaPO3 glass has a great contribution to the Na+ diffusion at the grain boundaries.

Fabrication of Porous Structure of BCP Sintered Bodies Using Microwave Assisted Synthesized HAp Nano Powder

2007 ◽  
Vol 534-536 ◽  
pp. 49-52 ◽  
Author(s):  
Min Ho Youn ◽  
Rajat Kanti Paul ◽  
Ho Yeon Song ◽  
Byong Taek Lee
Keyword(s):  
Calcium Phosphate ◽  
Porous Structure ◽  
Relative Density ◽  
Polymethyl Methacrylate ◽  
Biphasic Calcium Phosphate ◽  
Sintering Temperature ◽  
Microwave Assisted ◽  
Nano Powder ◽  
Maximum Value ◽  
Porous Biphasic Calcium Phosphate

Using microwave synthesized HAp nano powder and polymethyl methacrylate (PMMA) as a pore-forming agent, the porous biphasic calcium phosphate (BCP) ceramics were fabricated depending on the sintering temperature. The synthesized HAp powders was about 70-90 nm in diameter. In the porous sintered bodies, the pores having 150-180 μm were homogeneously dispersed in the BCP matrix. Some amounts of pores interconnected due the necking of PMMA powders which will increase the osteoconductivity and ingrowth of bone-tissues while using as a bone substrate. As the sintering temperature increased, the relative density increased and showed the maximum value of 79.6%. From the SBF experiment, the maximum resorption of Ca2+ ion was observed in the sample sintered at 1000°C.

Synthesis, Transport And Microstructural Properties of Nd1.85Ce0.15CuO4‐δ

1989 ◽  
Vol 169 ◽  
Author(s):  
Jong‐Gyu Lee ◽  
K.V. Ramanujachary ◽  
M. Greenblattî
Keyword(s):  
Solid State ◽  
Solution Method ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Uniform Size ◽  
X Ray ◽  
Solid State Route ◽  
Solution Precursor ◽  
Solution Route ◽  
State Resistance

AbstractThe n‐type superconductor, Nd1.85Ce0.15CuO4‐δ has been prepared by solid state reaction and solution precursor techniques under various conditions and characterized by means of X‐ray diffraction, magnetic susceptibility, electrical resistivity and SEM measurements. Samples prepared by solution method displayed higher normal state resistance but better superconducting volume fractions than those prepared by conventional ceramic techniques. In addition, the solution precursor technique reduces the sintering temperature from 1150°C (used for solid‐state route) to 1000°C in achieving the superconducting phase. The solution‐route yields particles with relatively uniform size distribution, but poor connectivity between the grains. In contrast, the solid state preparations yield well connected grains but with a larger distribution of sizes. The observed differences in the superconducting properties of samples prepared by different techniques have been attributed to the differences in their microstructure.

scholarly journals Synthesis and Structural Investigations of Ag-Added Ba-CuO Mixed Oxide for Gas Sensing

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Ahmed Mohamed El-Sayed ◽  
Fathy Mohamed Ismail ◽  
Saad Mabrouk Yakout
Keyword(s):  
Solid State ◽  
Gas Sensing ◽  
Sintering Temperature ◽  
Structure Characterization ◽  
Ceramic Processing ◽  
Sintering Process ◽  
Structural Investigations ◽  
X Ray ◽  
State Ceramic ◽  
Infrared Absorption Spectra

Compositions having the general formula BaTiO3- wt% Ag, where , and 2 have been prepared by solid state ceramic processing and sintered at 500 and for 5 h. Thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), infrared absorption spectra (IR), and scanning electron microscopy (SEM) were used to characterize the obtained sensor pellets. It was found that no solid state reaction took place between BaTiO3and CuO during sintering process. The sensitivity of the prepared sensors to CO2gas increases with increasing sintering temperature and Ag content. The correlation between Ag content at different sintering temperature and structure characterization is discussed.

scholarly journals Effects of LDL, Cholesterol, and Their Oxidized Forms on the Precipitation Kinetics of Calcium Phosphates

2003 ◽  
Vol 49 (12) ◽  
pp. 2027-2036 ◽  
Author(s):  
He-Ping Wang ◽  
Xiao-Jing Feng ◽  
Bao-Di Gou ◽  
Tian-Lan Zhang ◽  
Shan-Jin Xu ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Ldl Cholesterol ◽  
Calcium Phosphates ◽  
Oxidized Ldl ◽  
Precipitation Kinetics ◽  
X Ray ◽  
L Protein ◽  
Cholesteryl Linoleate ◽  
Nucleation Phase ◽  
Kinetics Of

Abstract Background: LDL, cholesterol, and their oxidized forms are known cardiovascular risk factors and are often found in atherosclerotic lesions of various stages. Little is known, however, about whether they are directly involved in the formation of calcium phosphate compounds. Methods: We used the pH-stat technique to follow the kinetics of calcium phosphate precipitation at pH 7.4, 37 °C, and ionic strength 0.150 mol/L, in the presence or absence of LDL, oxidized LDL, cholesterol, cholestane-3β,5α,6β-triol, and cholesteryl linoleate. The precipitates were characterized by x-ray diffraction, scanning and transmission electronic microscopy coupled with energy-dispersion x-ray analysis, and inductively coupled plasma atomic emission spectroscopy. Results: Under the experimental conditions, LDL (14.8 and 43.1 mg/L protein) had no significant effect on the precipitation kinetics. Oxidized LDL (14.8 and 43.1 mg/L protein) prolonged the nucleation phase and diminished the amount of total precipitate, and both the extent of oxidation and the concentration of the protein affected the kinetics. Cholesterol microcrystals (71.4 and 143 mg/L) made the nucleation phase shorter (300 min vs 390 min for the control), and the precipitated particles had an organic core and a shell composed of calcium phosphates. l-α-Phosphatidylcholine vesicles (143 mg/L), cholesterol (71.4 mg/L)/phospholipid (143 mg/L) mixed vesicles, cholesteryl linoleate (143 mg/L), and cholestane-3β,5α,6β-triol (71.4 mg/L) prolonged the nucleation phase. Conclusions: LDL is not involved directly in the precipitation of calcium phosphates. Oxidized LDL inhibits both nucleation and crystal growth, possibly by attracting calcium ions in the solution and thus reducing supersaturation. Cholesterol microcrystals serve as seeds for the precipitation of hydroxyapatite, whereas l-α-phosphatidylcholine, cholesteryl linoleate, and cholestane-3β,5α,6β-triol exhibit inhibitive effects on the nucleation of calcium phosphates.

Electrical Properties of Modified BNT Based Lead-Free Ceramics

2016 ◽  
Vol 872 ◽  
pp. 87-91
Author(s):  
Supalak Manotham ◽  
Tawee Tunkasiri ◽  
Pharatree Jaita ◽  
Pichitchai Butnoi ◽  
Denis Russell Sweatman ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Solid State ◽  
Electrical Properties ◽  
Sintering Temperature ◽  
Ferroelectric Properties ◽  
Lead Free ◽  
Second Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lead Free Ceramics

The properties of modified Bi0.5Na0.5TiO3 (BNT) based lead-free ceramics were investigated. The BNT-based ceramics were prepared by a solid-state mixed oxide method Phase formation was determined by X-ray diffraction technique (XRD). The X-ray diffraction analysis of the ceramics suggested that all samples exhibited a perovskite structure without second phase. The value of dielectric constant increased with increasing in sintering temperature. Moreover, high sintering temperatures could improve ferroelectric properties of BNT base lead-free ceramics.

Microstructures of Zirconium Titanate Powders and Ceramics Prepared by Solid-State Mixed Oxide Method

2008 ◽  
Vol 55-57 ◽  
pp. 145-148
Author(s):  
C. Puchmark ◽  
P. Tipparak
Keyword(s):  
Electron Microscope ◽  
Solid State ◽  
Scanning Electron Microscope ◽  
Heating Rate ◽  
Sintering Temperature ◽  
Zirconium Titanate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Jcpds File ◽  
Scanning Electron

Zirconium titanate (ZrTiO4): ZT powders were prepared by solid-state mixed oxide method. The mixed powder was calcined at various temperatures for 3 h ranging from 1100 to 1400 oC with a heating rate of 5 oC/min. X-ray diffraction analysis of the powders was performed using a diffractometer with Cu Ka. Pyrochlore phase was observed for calcinations below 1300 oC. In general, the strongest reflections apparent in patterns could be matched with a JCPDS file number 74-1504. The optimum calcination temperature for the formation of ZrTiO4 phase was found to be about 1300 oC for 3 h with heating rate of 5 oC/min. The microstructures of calcined powders were examined using scanning electron microscope (SEM). The particle size of powder increased with increasing calcination temperature. The ZT ceramics sintered at 1450, 1500, 1550 and 1600 oC for 4 h with heating rate of 5 oC/min, were checked for phase formation by X-ray diffraction. The density of sintered samples was measured by Archimedes method. The microstructures of sintered samples were examined using scanning electron microscope (SEM). The average grain sizes were checked by linear interception method. It was found that, the samples sintered at 1450 and 1500 oC gave rise to high purity ZT ceramics and the peaks matched well with ZrTiO4 phase in a JCPDS file number 74-1504. Unknown phases were found in ZT ceramics sintered at 1550 and 1600 oC. The value of density was in the range of 4.32 - 4.92 g/cm3 or 84.26 - 96.12 % of the ZT theoretical density. The densification of ZT ceramics decreased with increasing sintering temperature. The ZT ceramics sintered at 1450 and 1500 oC showed the average grain size of 8.55 and 12.55 µm, respectively. At sintering temperature 1550 and 1600 oC, morphology of grains changed to plate like crystals of second phases.

EFFECT OF SINTERING TEMPERATURE ON THE CRYSTAL STRUCTURE, MICROSTRUCTURE AND PHASE TRANSITION OF (Pb1-xSrx)TiO3 CERAMICS

2009 ◽  
Vol 02 (04) ◽  
pp. 193-197 ◽  
Author(s):  
RATTIPHORN SUMANG ◽  
THEERACHAI BONGKARN
Keyword(s):  
Phase Transition ◽  
Paraelectric Phase ◽  
Sintering Temperature ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Dielectric Constants ◽  
Paraelectric Phase Transition ◽  
Reaction Method ◽  
X Ray ◽  
Grain Sizes

Polycrystalline ( Pb 1-x Sr x) TiO 3 (PST) (x = 0.25, 0.50) ceramics were synthesized by the solid-state reaction method. PST sintering temperatures ranged between 1050–1250°C. The samples were characterized by X-ray diffractometer (XRD) and scanning electron microscopy (SEM). The sintered pellets showed pure perovskite in all samples. The lattice parameter c increased, while the lattice parameter a decreased with increasing sintering temperatures. The tetragonality and average grain sizes increased when sintering temperatures were increased. The dielectric constants vs temperature curves of PST ceramics with x = 0.25 and x = 0.50 associated with the ferroelectric to paraelectric phase transition, showed a maximum peak at around 311 and 139°C, respectively. The dielectric constants of both compositions were related with their densities.

The Effect of Stoichiometry to the Phase Formation of Barium Titanate

2012 ◽  
Vol 620 ◽  
pp. 198-202 ◽  
Author(s):  
Meor Ahmad Faris ◽  
Cheow Keat Yeoh ◽  
W.M. Arif ◽  
Pei Leng Teh ◽  
Nadia Abdullah
Keyword(s):  
Titanium Dioxide ◽  
Solid State ◽  
Barium Titanate ◽  
High Purity ◽  
Single Phase ◽  
Sintering Temperature ◽  
Barium Carbonate ◽  
Secondary Phase ◽  
X Ray Diffraction ◽  
X Ray

This paper focus on the effect of different ratio between barium (Ba) and titanium (Ti) to the production of high purity of barium titanate (BT). On this research, the sample was prepared by solid-state reaction between barium carbonate (BaCO3) and titanium dioxide (TiO2) powder at constant sintering temperature of 1350 °C. The sample was prepared at different ratio of Ba:Ti which are 1:0.9, 1:0.95, 1:1, 1:1.05, 1:1.1. All sintered BT was characterized by X-ray diffraction (XRD). All existed phase on these samples was determined and analyzed. Sample from ratio 1:1 produced almost a single phase of BT. While; samples from other ratio produce secondary phase which is barium orthotitanate (Ba2TiO4).

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