Surface and Electrochemical Analysis of Titanium Submitted to Alkaline Treatment by SEM, XRD and EIS

2008 ◽  
Vol 396-398 ◽  
pp. 381-384 ◽  
Author(s):  
Eduardo Mioduski Szesz ◽  
Cláudia E. B. Marino ◽  
Haroldo A. Ponte ◽  
Fabiana C. Nascimento ◽  
Carlos M. Lepienski ◽  
...  
Keyword(s):  
Structural Changes ◽  
Electrochemical Impedance ◽  
Alkali Treatment ◽  
Sodium Titanate ◽  
Impedance Analysis ◽  
Alkaline Treatment ◽  
Electrochemical Analysis ◽  
Titanium Metal ◽  
X Ray Diffraction ◽  
X Ray

Although titanium metal has been used intensively in the last years as biomaterial in the medical and dental areas its surface is not bioactive. In this work, titanium metal was submitted to an alkali treatment in order to make the metal surface bioactive. The samples were submitted to alkaline treatment (AT) using NaOH 5M aqueous solution at 60°C for 24 h and after that they were heated thermically to stabilize the layer obtained with AT. The bioactivity of the samples was evaluated soaking them into the simulated body fluid (SBF) at 36,5°C for 28 days. The morphological, structural changes and the electrochemical characterization were analyzed using scanning electron microscopy, x-ray diffraction and electrochemical impedance spectroscopy (EIS), respectively. It was verified that after AT plus heat treatment (HT) a sodium titanate layer was formed on the samples surface and after the bioactivity tests an apatite layer was formed. Impedance analysis show that the resistance of film on Ti is high and this value increases when the sample is soaked in SBF. It means that the apatite (HPA) film is occurring and the value of the capacitance with the presence of the HPA film (Cp) values indicate that the film maintain a compact and uniform characteristics.

Characterizations of Synthetic 8mol% YSZ with Comparison to 3mol %YSZ for HT-SOFC

2020 ◽  
Vol 38 (4A) ◽  
pp. 491-500
Author(s):  
Abeer F. Al-Attar ◽  
Saad B. H. Farid ◽  
Fadhil A. Hashim
Keyword(s):  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Structural Information ◽  
Impedance Analysis ◽  
High Energy ◽  
Yttria Stabilized Zirconia ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Powder Morphology ◽  
X Ray

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol% yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling to synthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolyte for high temperature solid oxide fuel cells (HT-SOFC). This work aims to evaluate the densification and ionic conductivity of the sintered electrolytes at 1650°C. The bulk density was measured according to ASTM C373-17. The powder morphology and the microstructure of the sintered electrolytes were analyzed via Field Emission Scanning Electron Microscopy (FESEM). The chemical analysis was obtained with Energy-dispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) was used to obtain structural information of the starting materials and the sintered electrolytes. The ionic conductivity was obtained through electrochemical impedance spectroscopy (EIS) in the air as a function of temperatures at a frequency range of 100(mHz)-100(kHz). It is found that the 3YSZ has a higher density than the 8YSZ. The impedance analysis showed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906 (S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a lower activation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, the prepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.

scholarly journals Preparation and Properties of Nanocellulose from Miscanthus x giganteus

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Valerii A. Barbash ◽  
Olha V. Yashchenko ◽  
Olesia A. Vasylieva
Keyword(s):  
Structural Changes ◽  
Thermochemical Treatment ◽  
Crystallinity Index ◽  
Alkaline Treatment ◽  
X Ray Diffraction ◽  
Miscanthus X Giganteus ◽  
X Ray ◽  
Second Stage ◽  
20 Nm ◽  
Hydrolysis Of

Miscanthus x giganteus stalks were used to make organosolvent pulp and nanocellulose. The organosolvent miscanthus pulp (OMP) was obtained through thermal treatment in the mixture of glacial acetic acid and hydrogen peroxide at the first stage and the alkaline treatment at the second stage. Hydrolysis of the never-dried OМP was carried out by a solution of sulfuric acid with concentrations of 43% and 50% and followed by ultrasound treatment. Structural changes and the crystallinity index of OMP and nanocellulose were studied by SEM and FTIR methods. X-ray diffraction analysis confirmed an increase in the crystallinity of OMP and nanocellulose as a result of thermochemical treatment. We show that nanocellulose has a density of up to 1.6 g/cm3, transparency up to 82%, and a crystallinity index of 76.5%. The AFM method showed that the particles of nanocellulose have a diameter in the range from 10 to 20 nm. A thermogravimetric analysis confirmed that nanocellulose films have a denser structure and lower mass loss in the temperature range of 320–440°C compared to OMP. The obtained nanocellulose films have high tensile strength up to 195 MPa. The nanocellulose obtained from OMP exhibits the improved properties for the preparation of new nanocomposite materials.

scholarly journals Microflower like Zinc Oxide/Cerium, Lanthanum Substituted Hydroxyapatite Bilayer Coating on Surgical Grade Stainless Steel for Corrosion Resistance, Antibacterial and Bioactive Properties

2020 ◽  
Vol 32 (4) ◽  
pp. 815-821 ◽  
Author(s):  
C. Sridevi ◽  
P. Karthikeyan ◽  
D. Dhivyapriya ◽  
L. Mitu ◽  
P. Maheswaran ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Impedance Analysis ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bilayer Coating ◽  
In Vitro Antibacterial Activity ◽  
Ft Ir ◽  
Bilayer Coatings

The growing evidence of beneficial role of zinc in bone has increased the interest of developing zinc-containing biomaterials for medical applications and specifically biocompatible coatings that can be deposited on metallic implants to benefit from their load-bearing capabilities. In present work, zinc oxide/cerium, lanthanum substituted (ZnO/Ce,La-HAP) hydroxyapatite bilayer coatings have been fabricated by electrodeposition technique. As developed, ZnO/Ce,La-HAP bilayer coatings were then structurally, morphologically and chemically characterized using Fourier-transform infrared spectroscopy(FT-IR), X-ray diffraction (XRD), higher resolution scanning electron microscopy (HRSEM) and energy dispersive X-ray spectroscopy (EDAX). The properties of corrosion performance of 316L SS were explored in Ringers solution using electrochemical analysis. The potentiodynamic polarization and impedance analysis demonstrated that the anticorrosion behavior of 316L SS was significantly increased by the bilayer coating. Cell viability in vitro, antibacterial activity and live/dead assay of ZnO/Ce,La-HAP bilayer coating were investigated. Hence, development of ZnO/Ce,La-HAP bilayer coating on 316L SS to make it suitable for biomedical applications.

X-Ray Diffraction (XRD) Analysis of Cellulose from Banana (Musa acuminata) Pseudo-Stem Waste

2014 ◽  
Vol 895 ◽  
pp. 174-177
Author(s):  
Noriean Azraaie ◽  
Nurul Aimi Mohd Zainul Abidin ◽  
Nur Ain Ibrahim ◽  
Nur Amira Mamat Razali ◽  
Fauziah Abdul Aziz ◽  
...  
Keyword(s):  
Alkali Treatment ◽  
Xrd Analysis ◽  
Alkaline Treatment ◽  
Musa Acuminata ◽  
X Ray Diffraction ◽  
Banana Plant ◽  
X Ray ◽  
Structure And Morphology ◽  
Banana Fibers ◽  
Bleaching Treatment

Alkali treatment and bleaching have been applied on banana fibers obtained from harvested pseudo-stem of the banana plant Musa acuminata collected in Banting, Selangor, Malaysia. The structure and morphology of the fibers have been found to be affected by the used of alkaline treatment and bleaching. The crystallite size and percentage crystallinity of the untreated (raw banana fibers) and treated (microfibrils cellulose) fibers were investigated using X-Ray Diffraction (XRD). XRD studies shows that the treated cellulose prepared by such chemical treatment (alkali and bleaching treatment) were more crystalline than the untreated banana fibers.

scholarly journals Minimizing Organic Waste Generated by Pineapple Crown: A Simple Process to Obtain Cellulose for the Preparation of Recyclable Containers

Recycling ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 24
Author(s):  
Diana Choquecahua Mamani ◽  
Kristy Stefany Otero Nole ◽  
Efrén Eugenio Chaparro Montoya ◽  
Dora Amalia Mayta Huiza ◽  
Roxana Yesenia Pastrana Alta ◽  
...  
Keyword(s):  
Chemical Treatment ◽  
Pyrolysis Temperature ◽  
Alkali Treatment ◽  
Alkaline Treatment ◽  
X Ray Diffraction ◽  
Acid Pretreatment ◽  
Chemical Methods ◽  
X Ray ◽  
Food Container ◽  
Single Chemical

In this study, cellulose was obtained from the residues of pineapple crown by means of simple acid pretreatment and subsequent alkaline treatment. The pretreatment consisted of washing, drying, and chopping with high shear at pH = 5 under heating. The content of cellulose, hemicellulose, and lignin in the pineapple crown was determined by chemical methods. The cellulose obtained was compared with commercial cellulose by Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis, and X-ray diffraction (XDR). Thus, from the obtained fiber cellulose, a food container was prepared, and its physical-mechanical properties were determined. Then, after alkali treatment, the purity of cellulose was 84.7% from the pineapple crown (56.0%) and was compared with commercial cellulose (95%). FTIR results confirmed the removal of the non-cellulosic compounds after alkali treatment. The maximum pyrolysis temperature increased to 356 °C, higher than the original fiber (322 °C), indicating greater thermal stability after chemical treatment. Furthermore, the crystallinity increased to 68% with respect to the original fiber (27%). The physical properties of the container showed a decrease in the parameters in wet 95% RH, as expected, thus facilitating its reuse. These results indicate that the pineapple crown cellulose can be obtained with significant purity, from a single chemical treatment. In addition, this polymorphous cellulose can be used to make ecofriendly reusable food containers.

scholarly journals Large-Area Sodium Titanate Nanorods Formed On Titanium Surface Via NaOH Alkali Treatment

2015 ◽  
Vol 60 (2) ◽  
pp. 1371-1374 ◽  
Author(s):  
K. Lee ◽  
D. Yoo
Keyword(s):  
Heat Treatment ◽  
Energy Conversion ◽  
Large Scale ◽  
Titanium Surface ◽  
Alkali Treatment ◽  
Sodium Titanate ◽  
Morphological Characterization ◽  
X Ray Diffraction ◽  
Large Area ◽  
X Ray

AbstractTi surfaces covered with large sodium titanate nanorods act as efficient electrodes for energy conversion and environmental applications. In this study, sodium titanate nanorod films were prepared on a Ti substrate in a 5M NaOH aqueous solution followed by heat treatment. The morphological characterization and the crystal structures of the sodium titanate nanorods were investigated via scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS). Thin amorphous sodium titanate layers formed during the alkali-treatment, and sodium titanate nanorods were obtained after heat treatment at a temperature of 700°C. The sodium titanate nanorods obtained at this temperature had a thickness of about 80 nm and a length of 1μm. The crystal structure of the sodium titanate was identified with the use of Na2Ti5O11. The nanorods were agglomerated at a temperature above 900°C, and large-scale nanorods formed on the Ti surface, which may be used for electrodes for energy conversion applications.

Microstructures and Cohesiveness of Alkali- and Heat-Treated Films on a Ti-15Zr-4Nb-4Ta Alloy

2007 ◽  
Vol 539-543 ◽  
pp. 3706-3711
Author(s):  
Sengo Kobayashi ◽  
Koji Murakami ◽  
Kiyomichi Nakai ◽  
Makoto Hino
Keyword(s):  
Heat Treatment ◽  
Electron Spectroscopy ◽  
Alkali Treatment ◽  
Sodium Titanate ◽  
X Ray Diffraction ◽  
Compositional Gradient ◽  
X Ray ◽  
Heat Treated ◽  
Naoh Solution ◽  
Scratch Tests

Microstructures of alkali- and/or heat-treated films on a Ti-15Zr-4Nb-4Ta alloy were analyzed by means of scanning electron microscopy, thin film X-ray diffraction and Auger electron spectroscopy. The cohesiveness of films was also evaluated by scratch tests. The films were formed by immersion in 5M aqueous NaOH solution at 60 °C for 86.4 ks (alkali treatment) followed by heating at 400–600 °C for 3.6 ks. The film on alloy formed by alkali treatment exhibits the same strucutre as that formed on an alkali-treated titanium. Compositional gradient of alloying elements, Zr, Nb and Ta, is detected in the film. The cohesion of alkali-treated film is considerably increased by the heat treatment, and the maximum cohesion is obtained by heating at 600 °C. The increase in cohesion of alkali-treated film by heat treatment is due to both the diffusion of Zr into film and the formation of sodium titanate on substrate.

Effect of Zn Content on Structure, Roughness and Corrosion Behavior of Zn-Ni Alloys

2019 ◽  
Vol 17 (17) ◽  
pp. 17-22
Author(s):  
Hayette Faid
Keyword(s):  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Stripping Voltammetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ni Alloys ◽  
Sulfate Bath ◽  
Zn Content ◽  
Polarization Test ◽  
Δ Phase

AbstractIn this work, Zn-Ni alloys have been deposited on steel from sulfate bath, by electrodeposition method. The effect of Zn content on deposits properties was studied by cyclic voltammetry (CV), chronoaperometry (CA), linear stripping voltammetry (ALSV) and diffraction (XRD) and scanning electronic microscopy (SEM). The corrosion behavior in 3.5 wt. NaCl solution was examined using anodic polarization test and electrochemical impedance spectroscopy. X-ray diffraction of show that Zn-Ni alloys structure is composed of δ phase and γ phase, which increase with the decrease of Zn content in deposits. Results show that deposits obtained from bath less Zn2+ concentration exhibited better corrosion resistance.

scholarly journals Effect of Molybdenum Content on the Corrosion and Microstructure of Low-Ni, Co-Free Maraging Steels

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 852
Author(s):  
Asiful H. Seikh ◽  
Hossam Halfa ◽  
Mahmoud S. Soliman
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Microstructural Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Alloying Element ◽  
X Ray ◽  
Maraging Steels ◽  
Eds Analysis ◽  
Electroslag Refining

Molybdenum (Mo) is an important alloying element in maraging steels. In this study, we altered the Mo concentration during the production of four cobalt-free maraging steels using an electroslag refining process. The microstructure of the four forged maraging steels was evaluated to examine phase contents by optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. Additionally, we assessed the corrosion resistance of the newly developed alloys in 3.5% NaCl solution and 1 M H2SO4 solution through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Furthermore, we performed SEM and energy-dispersive spectroscopy (EDS) analysis after corrosion to assess changes in microstructure and Raman spectroscopy to identify the presence of phases on the electrode surface. The microstructural analysis shows that the formation of retained austenite increases with increasing Mo concentrations. It is found from corrosion study that increasing Mo concentration up to 4.6% increased the corrosion resistance of the steel. However, further increase in Mo concentration reduces the corrosion resistance.

Preliminary Preparation and Characterization Studies of Cellulose from Merbau (Intsia bijuga)

2012 ◽  
Vol 620 ◽  
pp. 314-319
Author(s):  
Nur Amira Mamat Razali ◽  
Fauziah Abdul Aziz ◽  
Saadah Abdul Rahman
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Alkaline Treatment ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Preliminary Preparation ◽  
Characterization Studies ◽  
Scanning Electron

Hardwood is wood from angiosperm trees. The characteristic of hardwood include flowers, endosperm within seeds and the production of fruits that contain the seeds. This paper aims to discuss the preparation and characterization of cellulose obtained from hardwood. The hardwood Merbau (Intsia bijuga) was chosen as raw material in this study. Alkaline treatment and delignification methods were used for the preparation of cellulose. Acid hydrolysis was employed to produce cellulose nanocrystal (CNC). The treated and untreated samples were characterized using x-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The final product, from both trated and untreated samples were then compared.

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