Hydrothermal Processing for Increasing the Hydroxyl Ion Concentration in Hydroxyl Depleted Hydroxyapatite

2018 ◽  
Vol 762 ◽  
pp. 42-47
Author(s):  
Darta Ubele ◽  
Liene Pluduma ◽  
Karlis Agris Gross ◽  
Arturs Viksna
Keyword(s):  
Thermal Spraying ◽  
Ion Concentration ◽  
Hydrothermal Processing ◽  
X Ray Diffraction ◽  
Ion Content ◽  
X Ray ◽  
Hydroxyapatite Powder ◽  
Hydroxyapatite Coatings ◽  
Hydroxyl Ion ◽  
Thermally Sprayed

Thermal spraying is commercially used to produce hydroxyapatite coatings, but the high temperature depletes hydroxyl ions in the structure. To return hydroxyapatite to its original state, it is necessary to restore the hydroxyl ion content in the structure. In this work, the effect of hydrothermal treatment on the hydroxyl ions was investigated in hydroxyapatite powder and thermally sprayed hydroxyapatite coatings. Samples were hydrothermally treated at 200 °C for 24 h and 48 h. Chemical phases were determined by X-ray diffraction, functional groups and hydroxyl ion concentration was examined by Fourier transform infra-red spectroscopy. Results showed that hydrothermal processing of hydroxyapatite coatings at 200 °C for 48 hours produced the greatest increase in the hydroxyl ion concentration by 29%.

Effect of Bond Coat Diffusion on Adhesion Behaviour of Hard Alloy Powder NiCrBCSi (Fe) Coatings Thermally Sprayed on 60CrMn4 Steel

2008 ◽  
Vol 273-276 ◽  
pp. 8-13
Author(s):  
S. Abdi ◽  
B. Malki ◽  
S. Lebaili
Keyword(s):  
Bond Coat ◽  
Steel Substrate ◽  
Substrate Surface ◽  
Thermal Spraying ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chromium Plating ◽  
Previously Treated ◽  
Thermally Sprayed ◽  
Large Diffusion

The object of the present work is to study the spraying of poly-powders nickel bases containing Cr, Si, C and B elements addition with variable percentage of iron, deposited on a steel substrate by oxy fuel thermal spraying. The substrate surface was previously treated by Al–Ni bond coat and post–annealing at 650°C. The spraying powder and coating micro structure were investigated by combination of X-ray diffraction, electron microprobe and scanning electron microscope coupled to an analyzer energy dispersive x-ray. The adherence to substrate was determined by using shear test for adhesion. The result of this study was to investigate to compare potentials of HVOF sprayed NiCrBCSi and satellite 6 coating for a possible to replacement of hard chromium plating. A good adherence of coating NiCrBCSi (Fe) on steel substrate is explained by formation of large diffusion zone in interface after annealing and by the nature of the structure deposit duplexes.

scholarly journals Cloning, expression, purification, crystallization and preliminary X-ray diffraction of a lysine-specific permease fromPseudomonas aeruginosa

2014 ◽  
Vol 70 (10) ◽  
pp. 1362-1367 ◽  
Author(s):  
Emmanuel Nji ◽  
Dianfan Li ◽  
Declan A. Doyle ◽  
Martin Caffrey
Keyword(s):  
Metal Ion ◽  
Cell Volume Regulation ◽  
Ion Concentration ◽  
Size Exclusion ◽  
Substrate Selectivity ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Exclusion Chromatography

The prokaryotic lysine-specific permease (LysP) belongs to the amino acid–polyamine–organocation (APC) transporter superfamily. In the cell, members of this family are responsible for the uptake and recycling of nutrients, for the maintenance of a constant internal ion concentration and for cell volume regulation. The detailed mechanism of substrate selectivity and transport of L-lysine by LysP is not understood. A high-resolution crystal structure would enormously facilitate such an understanding. To this end, LysP fromPseudomonas aeruginosawas recombinantly expressed inEscherichia coliand purified to near homogeneity by immobilized metal ion-affinity chromatography (IMAC) and size-exclusion chromatography (SEC). Hexagonal- and rod-shaped crystals were obtained in the presence of L-lysine and the L-lysine analogue L-4-thialysine by vapour diffusion and diffracted to 7.5 Å resolution. The diffraction data were indexed in space groupP21, with unit-cell parametersa= 169.53,b= 169.53,c= 290.13 Å, γ = 120°.

scholarly journals Influence of Mineral Admixtures on Corrosion Inhibition Effect of Nitrites

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Mengna Yang ◽  
Junzhe Liu ◽  
Hui Wang ◽  
Yushun Li ◽  
Yanhua Dai ◽  
...  
Keyword(s):  
Fly Ash ◽  
Corrosion Inhibition ◽  
Ion Concentration ◽  
Mineral Admixtures ◽  
X Ray Diffraction ◽  
Nitrite Ion ◽  
X Ray ◽  
Inhibition Effect ◽  
Diffraction Patterns ◽  
Micro Analysis

Chemical quantitative analysis of effective anticorrosion component and micro-analysis of hydration products of fly ash and slag on the influence of the nitrites corrosion inhibition was studied by the free nitrite ion concentration and X-ray diffraction pattern. The free nitrite ion concentration was used to describe the corrosion inhibition effect of nitrites. And the X-ray diffraction patterns were used to analyze the adsorption properties. The research results show that fly ash and slag were beneficial for improving the corrosion inhibition effect of nitrites. Cement-based materials with slag at low content presented high free nitrite ion concentration, but the addition of low content of fly ash harmed the corrosion inhibition effect of nitrites. The specimens incorporated with both fly ash and slag can reach the highest free nitrite ion concentration when the compounding proportion was 1:1. It was concluded that the extent of mineral admixtures of the corrosion inhibition effect of nitrites was affected by its type and content.

Production and Characterization of HVOF Sprayed NiCr-TiC Coatings Using SHS Powder Feedstock

2000 ◽  
Author(s):  
M.T. Blatchford ◽  
A.J. Horlock ◽  
D.G. McCartney ◽  
P.H. Shipway ◽  
J.V. Wood
Keyword(s):  
Thermal Spraying ◽  
Xrd Analysis ◽  
Powder Size ◽  
Coating Properties ◽  
X Ray Diffraction ◽  
Hvof Spraying ◽  
X Ray ◽  
Wear Rates ◽  
Powder Feedstock

Abstract In this paper, the production of NiCr-TiC powder by SHS, suitable for HVOF spraying, is discussed together with results on the microstructure and coating properties. Compacts for SHS were prepared by mixing elemental Ti and C with pre-alloyed Ni-20wt.% Cr powder to give an overall composition of 35wt.% NiCr and 65wt.% TiC. These were then ignited and a self-sustaining reaction proceeded to completion. Reacted compacts were crushed, sieved, and classified to give feedstock powders in size ranges of 10-45 µm and 45-75 µm. All powder was characterized prior to spraying based on particle size distribution, x-ray diffraction (XRD), and scanning electron microscopy (SEM/EDS). Thermal spraying was performed using both H2 and C3H6 as fuel gases in a UTP/Miller Thermal HVOF system. The resulting coatings were characterized by SEM and XRD analysis, and the microstructures correlated with powder size and spray conditions. Abrasive wear was determined by a modified 'dry sand rubber wheel' (DSRW) test and wear rates were measured. It has been found that wear rates comparable to those of HVOF sprayed WC-17wt% Co coatings can be achieved.

Mechanochemical Synthesis of Magnesium Doped Hydroxyapatite: Powder Characterization

2013 ◽  
Vol 372 ◽  
pp. 62-65 ◽  
Author(s):  
Sharifah Adzila ◽  
Singh Ramesh ◽  
Iis Sopyan ◽  
C.Y. Tan ◽  
Mohd. Hamdi ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Present Method ◽  
X Ray Diffraction ◽  
Mechanochemical Method ◽  
Xrd Pattern ◽  
X Ray ◽  
Hydroxyapatite Powder ◽  
Powder Properties ◽  
Mg Doped

In this study, the mechanochemical method was employed to synthesize hydroxyapatite (HA) and magnesium (Mg) doped hydroxyapatite (HA) powders. The effect of Mg2+ into the synthesized HA powder properties were investigated. Characterization of the synthesized HA and Mg doped HA at various concentrations (1% - 5% MgHA) were accomplished through X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analyses. nanosize of HA and Mg doped HA powders were successfully synthesized through the present method as indicated from the different peaks intensity and adsorption bands obtained in XRD pattern and FTIR respectively.

Performance Thermally Sprayed Coatings Tests when Subject to Adhesive Wear

2014 ◽  
Vol 802 ◽  
pp. 349-352
Author(s):  
A.B.C. Arnt ◽  
M.R. da Rocha ◽  
G.F. Marangoni
Keyword(s):  
Room Temperature ◽  
Adhesive Wear ◽  
Wear Test ◽  
Test Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermally Sprayed Coatings ◽  
Oxygen Fuel ◽  
Thermally Sprayed ◽  
Sprayed Coatings

In this study it was evaluated the performance of coatings based on Cr3C2-25 (80Ni-20Cr) and CrC-30NiCr. The coatings were deposited by high velocity oxygen fuel (HVOF), with an average thickness of layer equal to 7.8μm. Samples were subjected to adhesive wear test (according ASTM G99) with a pin Ø 6 mm (SAE 52100). In the test was applied normal force equal to 50 N and tangential speed equal to 0.5 m/s. The test time was 30 minutes at room temperature, without lubrification. The wear surfaces were characterized by optical microscopy, scanning electron microscopy and X-ray diffraction. The microhardness of the coatings was also evaluated. The results showed that the coating based on Cr3C2-25(80Ni-20Cr) presented a performance ten times higher in wear resistance when compared to coating CrC-30NiCr.

In Vitro Study of Microplasma Sprayed Hydroxyapatite Coatings in Simulated Body Fluid

2009 ◽  
Vol 79-82 ◽  
pp. 815-818 ◽  
Author(s):  
Qiu Ying Zhao ◽  
Ding Yong He ◽  
Xiao Yan Li ◽  
Jian Min Jiang
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Carbonate Apatite ◽  
In Vitro Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Phases ◽  
Hydroxyapatite Coatings ◽  
Vitro Test

Hydroxyapatite (HA) coatings were deposited onto Ti6Al4V substrate by microplasma spraying (MPS) in the current research. The morphology, phase compositions, and percentage of crystallinity of the coatings were characterized by means of scanning electron microscopy (SEM) and X-ray diffraction. An in vitro evaluation by soaking the coatings in simulated body fluid (SBF) for up to 14 days was conducted aiming at the evaluation of their bioactivity. Results from the present investigation suggest that microplasma sprayed HA coatings exhibited certain roughness, pores, and microcracks. Thermal decomposition existed in the coatings where HA, α-TCP，β-TCP, amorphous phases, and CaO-exclusive impurities were observed. The in vitro test indicated that HA coatings deposited by MPS possessed better bioactivity and stability. A layer of carbonate-apatite covered most of the coating surface, which did not exhibit significant spalling after incubation in SBF.

Influence of Sterilization with γ-Irradiation in the Degradation of Plasma Sprayed Hydroxyapatite Coatings

2006 ◽  
Vol 514-516 ◽  
pp. 1054-1058 ◽  
Author(s):  
Tânia Costa ◽  
Ana Paula Serro ◽  
Eduardo Pires ◽  
Rogerio Colaço
Keyword(s):  
Mechanical Behaviour ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Γ Irradiation ◽  
Water Contact ◽  
X Ray ◽  
Angle Measurements ◽  
Hydroxyapatite Coatings ◽  
Plasma Sprayed ◽  
Irradiation Process

The influence of sterilization with γ-irradiation in the properties of plasma sprayed hydroxyapatite (HAp) coatings used for medical implants is investigated in this work. HAp coatings were applied on titanium alloy substrates by plasma spraying and then submitted to 1 and 10 cycles of sterilization with γ-irradiation. As-applied HAp coatings were used as control samples. Afterwards, the modifications on the samples, induced by the irradiation process, were evaluated by X-ray diffraction and X-ray photoelectron spectroscopy (XPS). Water contact angle measurements as well as adhesion tests were also carried out in order to evaluate the influence of the irradiation process on the wettability and mechanical behaviour of the HAp coatings. No microstructural modifications were detected by X-ray diffraction after sterilization. However, the results show that sterilization with γ-irradiation originates modifications of the surface of HAp, as detected by a change of color of the coatings and by the XPS analysis. Nevertheless, these modifications do not result in significant changes in the wettability and mechanical behaviour of the HAp coatings.

Comparative Study of Bioceramic Powders Synthesis Based on Calcium and Phosphates

2018 ◽  
Vol 16 (14) ◽  
pp. 13-16
Author(s):  
Dan Nicolae Ungureanu ◽  
Daniela Avram ◽  
Nicolae Angelescu ◽  
Adrian Catangiu ◽  
Florina Violeta Anghelina ◽  
...  
Keyword(s):  
Comparative Study ◽  
X Ray Diffraction ◽  
Hard Tissue ◽  
X Ray ◽  
Hydroxyapatite Powder ◽  
Investigation Methods ◽  
Light Diffusion ◽  
Degree Of Crystallization ◽  
Size And Morphology ◽  
Co Precipitation

Abstract In this paper is presented a comparative study regarding the synthesis of hydroxyapatite powders. The chosen method of synthesis of this biomaterial was chemical co-precipitation. The structure, size and morphology of the obtained powders were analyzed by X-ray diffraction, infrared spectroscopy - FTIR, dynamic light diffusion DLS tehnique and scanning electron microscopy-SEM. The results obtained were compared with those obtained on a commercial hydroxyapatite powder. Investigation methods have confirmed the synthesis of a high purity hydroxyapatite with a optimal degree of crystallization and crystallinity for the reconstruction and regeneration of hard tissue.

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