scholarly journals Evaluación de la degradación de superficies de fluorapatita mediante técnicas electroquímicas. (Degradation Assessment of Fluorapatite Surfaces using Electrochemical Techniques)

2015 ◽  
Vol 6 (1) ◽  
pp. 33 ◽  
Author(s):  
L. J. Reyes Jaimes ◽  
H. A. González Romero ◽  
A. Sandoval Amadora ◽  
D. Y. Peña Ballesteros ◽  
H. A. Estupiñán Durán
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Active Surface ◽  
Apatite Formation ◽  
X Ray ◽  
Cathodic Electrodeposition ◽  
High Concentrations

ResumenSe evaluó el efecto del pH de fluido corporal simulado en la formación de apatitas y en la degradación de superficies de la aleación Ti6Al4V recubiertas con Fosfato de Calcio mediante la técnica de lectrodeposición catódica. Como variables de estudio se tomaron el pH del fluido corporal simulado y el tiempo de inmersión de los recubrimientos. Mediante microscopia electrónica de barrido, espectroscopia de energía dispersiva, difracción de rayos X y absorción atómica se pudo corroborar la formación de apatitas, y la degradación de los recubrimientos se evaluó mediante Espectroscopia de impedancia electroquímica y curvas de polarización potenciodinámicas. Los resultados obtenidos muestran que los recubrimientos tenían altas concentraciones de Fluorapatita (Ca5(PO4)3F) y que su formación se ve favorecida a medida que el pH del fluido corporal simulado y el tiempo de inmersión aumenta. Por otra parte, se obtuvo que las muestras evaluadas a pH de 7,2 son menos estables termodinámicamente, sin embargo, las evaluadas a 7,6 presentan una superficie más activa, por lo que se obtiene una mayor velocidad de degradación. AbstractThe pH eect of a Simulated Body Fluid in the apatite formation and the degradation of the Ti6Al4V alloy surfaces, coated by calcium phosphate obtained through cathodic electrodeposition was evaluated. The simulated body fluid pH and the coating immersion time were taken as variables. The formation of apatite was corroborated by Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X Ray Diraction and Atomic Absorption Techniques. The coating degradation was assessed by the Electrochemical Impedance Spectroscopy and the Potential Dynamic Polarization Curves. The results have shown that the coatings had high concentrations of fluorapatite (Ca5(PO4)3F) and its formation was favored as the simulated body fluid pH and the immersion time increases. Moreover, it was found that the coatings samples evaluated at pH 7.2 were less thermodynamically steady, however, the evaluated coating at pH 7.6 exhibited a more active surface, so that a higher rate of degradation is obtained.

scholarly journals Role of Vanadium Additions on the Corrosion Mitigation of Ti-6Al-xV Alloy in Simulated Body Fluid

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 903 ◽  
Author(s):  
El-Sayed M. Sherif ◽  
Sameh A. Ragab ◽  
Hany S. Abdo
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cyclic Potentiodynamic Polarization ◽  
Elemental Analyses ◽  
Corrosion Behaviors

The manufacturing of different Ti-6Al-xV (x = 2, 4, 6, and 8 wt.%) alloys using a mechanical alloying technique was reported. The corrosion behaviors of these newly fabricated alloys after 1, 24, and 48 h exposure to a simulated body fluid (SBF) were assessed using cyclic potentiodynamic polarization, electrochemical impedance spectroscopy, and chronoamperometric measurements. Surface morphology and elemental analyses after corrosion for 48 h in SBF were reported using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) examinations. An X-ray diffraction investigation characterized the phase analyses. All results indicated that the increase of V content significantly decreases both uniform and pitting corrosion. This effect also increases with prolonging the immersion time to 48 h before measurement.

scholarly journals Improved bioactivity of GUMMETAL®, Ti59Nb36Ta2Zr3O0.3, via formation of nanostructured surfaces

2018 ◽  
Vol 9 ◽  
pp. 204173141877417 ◽  
Author(s):  
Shiva Kamini Divakarla ◽  
Seiji Yamaguchi ◽  
Tadashi Kokubo ◽  
Dong-Wook Han ◽  
Jae Ho Lee ◽  
...  
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Cell Attachment ◽  
Cell Number ◽  
Calcium Titanate ◽  
Apatite Formation ◽  
X Ray ◽  
Nanostructured Surfaces ◽  
Implant Integration

The leading reason for implant revision surgery globally is lack of implant integration with surrounding bone. A new titanium alloy GUMMETAL® (Ti59Nb36Ta2Zr3O0.3) is currently used in biomedical devices and has a Young’s modulus that is better matched to bone. The surface was subject to NaOH, CaCl2, heat and water treatment (BioGum) after which the surfaces were evaluated using atomic force microscope, scanning electron microscope, X-ray diffractometer and elemental analysis using energy dispersive X-ray. To demonstrate enhanced bone bonding ability and cytocompatibility, apatite formation in simulated body fluid and in vitro stem cell attachment, proliferation and cytoskeleton organisation were examined. The formation of a ~200 nm nanoscale needle-like calcium titanate network on the surface following treatment was revealed and upon soaking in simulated body fluid, the formation of a ~5 µm layer of apatite. Metabolic activity of rat bone marrow stem cells on BioGum was increased in comparison to control and the cell number appeared greater, with more elongated morphology as early as 2 h post-seeding. This positions the modification as a simple and potentially universal technology for the improvement of implant integration.

scholarly journals Corrosion and Corrosion Inhibition of High Strength Low Alloy Steel in 2.0 M Sulfuric Acid Solutions by 3-Amino-1,2,3-triazole as a Corrosion Inhibitor

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
El-Sayed M. Sherif ◽  
Adel Taha Abbas ◽  
D. Gopi ◽  
A. M. El-Shamy
Keyword(s):  
Sulfuric Acid ◽  
Corrosion Inhibition ◽  
Polarization Resistance ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Hsla Steel ◽  
Electrochemical Techniques ◽  
High Strength ◽  
X Ray ◽  
Sulfuric Acid Solutions

The corrosion and corrosion inhibition of high strength low alloy (HSLA) steel after 10 min and 60 min immersion in 2.0 M H2SO4solution by 3-amino-1,2,4-triazole (ATA) were reported. Several electrochemical techniques along with scanning electron microscopy (SEM) and energy dispersive X-ray (EDS) were employed. Electrochemical impedance spectroscopy indicated that the increase of immersion time from 10 min to 60 min significantly decreased both the solution and polarization resistance for the steel in the sulfuric acid solution. The increase of immersion time increased the anodic, cathodic, and corrosion currents, while it decreased the polarization resistance as indicated by the potentiodynamic polarization measurements. The addition of 1.0 mM ATA remarkably decreased the corrosion of the steel and this effect was found to increase with increasing its concentration to 5.0 mM. SEM and EDS investigations confirmed that the inhibition of the HSLA steel in the 2.0 M H2SO4solutions is achieved via the adsorption of the ATA molecules onto the steel protecting its surface from being dissolved easily.

scholarly journals Atomic Layer Deposition of aTiO2 Layer on Nitinol and Its Corrosion Resistance in a Simulated Body Fluid

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 659
Author(s):  
Rebeka Rudolf ◽  
Aleš Stambolić ◽  
Aleksandra Kocijan
Keyword(s):  
Corrosion Resistance ◽  
Simulated Body Fluid ◽  
Atomic Layer Deposition ◽  
Body Fluid ◽  
Electrochemical Impedance ◽  
Atomic Layer ◽  
Tio2 Layer ◽  
High Tendency ◽  
X Ray ◽  
Layer Deposition

Nitinol is a group of nearly equiatomic alloys composed of nickel and titanium, which was developed in the 1970s. Its properties, such as superelasticity and Shape Memory Effect, have enabled its use, especially for biomedical purposes. Due to the fact that Nitinol exhibits good corrosion resistance in a chloride environment, an unusual combination of strength and ductility, a high tendency for self-passivation, high fatigue strength, low Young’s modulus and excellent biocompatibility, its use is still increasing. In this research, Atomic Layer Deposition (ALD) experiments were performed on a continuous vertical cast (CVC) NiTi rod (made in-house) and on commercial Nitinol as the control material, which was already in the rolled state. The ALD deposition of the TiO2 layer was accomplished in a Beneq TFS 200 system at 250 °C. The pulsing times for TiCl4 and H2O were 250 ms and 180 ms, followed by appropriate purge cycles with nitrogen (3 s after the TiCl4 and 2 s after the H2O pulses). After 1100 repeated cycles of ALD depositing, the average thickness of the TiO2 layer for the CVC NiTi rod was 52.2 nm and for the commercial Nitinol, it was 51.7 nm, which was confirmed by X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscope (SEM) using Energy-dispersive X-ray (EDX) spectroscopy. The behaviour of the CVC NiTi and commercial Nitinol with and without the TiO2 layer was investigated in a simulated body fluid at body temperature (37 °C) to explain their corrosion resistance. Potentiodynamic polarisation measurements showed that the lowest corrosion current density (0.16 μA/cm2) and the wider passive region were achieved by the commercial NiTi with TiO2. Electrochemical Impedance Spectroscopy measurements revealed that the CVC NiTi rod and the commercial Nitinol have, for the first 48 h of immersion, only resistance through the oxide layer, as a consequence of the thin and compact layer. On the other hand, the TiO2/CVC NiTi rod and TiO2/commercial Nitinol had resistances through the oxide and porous layers the entire immersion time since the TiO2 layer was formatted on the surfaces.

In Vitro Bioactivity of Composite of Nanophase Titania/Bioactive Glass-Ceramic in Simulated Body Fluid

2005 ◽  
Vol 288-289 ◽  
pp. 171-174
Author(s):  
Hui Wang ◽  
Bang Cheng Yang ◽  
Qi Feng Yu ◽  
Dayi Wu ◽  
Xing Dong Zhang
Keyword(s):  
Simulated Body Fluid ◽  
Bioactive Glass ◽  
Glass Ceramic ◽  
Body Fluid ◽  
Mechanical Analysis ◽  
Apatite Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Biomechanical Compatibility

Titania ceramics is lack of bone-bonding ability even if it has excellent biocompatibility. Recently, it is even found that the nanophase titania ceramics could enhance the proliferation of osteoblasts. If the bone-bonding ability of this material is improved, it would be a potential bone replacement material. Bioactive glass-ceramic (BGC) is provided with the best bioactivity in biomaterials. In this study, the apatite formation ability and the mechanic properties of titania ceramic were investigated by the accession of BGC. Four samples: TiO2 ceramic, TiO2 +10%BGC, TiO2 +20%BGC and BGC were prepared respectively. These ceramics were exposed to a simulated body fluid (SBF) for 7, 14 and 21d. Scanning electron microscopy (SEM), energy dispersive X-ray detector (EDX) and thin film X-ray diffraction (TF-XRD) results showed that the apatite formation of the ceramics was improved by adding BGC into nanophase titania ceramic. The mechanical analysis showed the biomechanical compatibility was also improved by adding BGC into nanophase titania ceramic.

Bioactivity Behavior of YSZ-Al2O3/10HAP Bioceramics Composites in Simulated Body Fluid

2014 ◽  
Vol 980 ◽  
pp. 13-17
Author(s):  
M.R.N. Liyana ◽  
Nur Maizatul Shima Adzali ◽  
M.Z.M. Zamzuri
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Immersion Time ◽  
Ph Value ◽  
Dental Materials ◽  
Biological Response ◽  
Ion Concentration ◽  
Human Blood Plasma ◽  
Apatite Formation

Yttria-stabilized zirconia and alumina made significant contributions to the development of health care industry, specifically as orthopedic and dental materials. Both bioceramics are nearly inert ceramics, as they do not allow the interfacial bonding with tissue. Thus, it is necessary to provide bioactive surrounding as to elicit a specific biological response at the interface of material. This research reported the microstructure and bioactivity behavior of YSZ-Al2O3/10HAP with 30 wt. % and 60 wt. % of YSZ content. Powders were mixed before being compacted at 225MPa using uni-axial press machine. The composites were sintered at 1200 ̊C with heating rate of 10 ̊C/min. In-vitro bioactivity behavior of the composites were evaluated by immersing the composites into simulated body fluid. Results from x-ray diffraction pattern, confirmed the phase formation of apatite by the presence of Ca2P2O7, and CaO that might be useful on implant cell interaction in a body environment. The apatite formation was observed on the surfaces of the composites by SEM only after 9 days of immersion and subsequently apatite nucleation increased with prolonging immersion time. The dynamic changes in pH, between ion concentration in SBF and bioceramics surfaces correspondedwith an immersion time. Up to 30 days of immersion, the pH value of SBF stabilized approximately around pH 7.4-7.6, similar to the human blood plasma. Formation of apatite on composites surface of prepared YSZ-Al2O3/10HAP bioceramics may contribute to the improved biocompatibility and osteoconductivity.

scholarly journals Beneficial Effects of Vanadium Additions on the Corrosion of Ti6AlxV Alloys in Chloride Solutions

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 264 ◽  
Author(s):  
El-Sayed M. Sherif ◽  
Hany S. Abdo ◽  
Nabeel H. Alharthi
Keyword(s):  
Electron Microscopy ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Test Medium ◽  
X Ray ◽  
Beneficial Effects ◽  
Cyclic Potentiodynamic Polarization ◽  
Scanning Electron

The beneficial effects of V addition on the corrosion of a newly manufactured Ti6AlxV (x = 2 wt %, 4 wt %, 6 wt %, and 8 wt %) alloys after various exposure periods in 3.5% NaCl solutions were reported. The Ti6AlxV were produced from their raw powders using mechanical alloying. Several electrochemical techniques such as electrochemical impedance spectroscopy, cyclic potentiodynamic polarization, and potentiodynamic current versus time at 300 mV experiments were conducted. The surface morphology and the elemental analysis were performed using scanning electron microscopy and energy dispersive X-ray analyses. All results were consistent with each other revealing that the increase of V content increases the resistance of the alloys against corrosion. The increase of corrosion resistance was achieved by the role of V in decreasing the rate of corrosion as a result of the formation of oxide films on the surface of the alloys. This effect was found to increase with prolonging the immersion time of the Ti6AlxV alloys in the test medium from 1 h to 24 h and further to 48 h.

scholarly journals Effect of varying phosphate content on the structure and properties of sol-gel derived SiO2-CaO-P2O5 bio-glass

2021 ◽  
Vol 2080 (1) ◽  
pp. 012018
Author(s):  
Syed Nuzul Fadzli Syed Adam ◽  
Firuz Zainuddin ◽  
Azlin Fazlina Osman
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
High Surface ◽  
Sol Gel ◽  
Glassy Matrix ◽  
Apatite Formation ◽  
Phosphate Content ◽  
X Ray ◽  
Carbonated Apatite

Abstract In this work, biocompatible glass (bioglass) particles were prepared by low temperature, acid catalysed sol-gel method. The effect of varying phosphate (P2O5) content (10, 15 and 20 mol %) in the sol-gel derived glass composition were studied. The sol-gel derived bioglass particles were compacted into cylindrical pellets via hydraulic press machine and sintered at 600°C for 3 hours. The bioglass particulates were analysed by x-ray fluorescence (XRF), Fourier Transformed Infrared (FTIR), X-Ray Diffraction (XRD) and nitrogen gas adsorption. Meanwhile, the sintered bioglass pellets were analysed by FTIR, XRD and FESEM-EDX. Furthermore, in vitro bioactivity analysis was performed by immersion in simulated body fluid (SBF) for 14 days. Bioglass particulates with high glassy phase, high surface area and high porosities were obtained for all compositions. Increasing of phosphate content to 20 mol% particularly reduced the porous characteristics of the bioglass particulates. Furthermore, leads to higher bridging oxygen (BO) atoms, higher amorphous silicate networks, lower glass crystallinity and higher number of phosphate crystallites within the amorphous glassy matrix. Increased to 20 mol% of phosphate also reduced the ability of the bioglass surface to induce carbonated apatite formation when immersed in simulated body fluid (SBF) solution.

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