Search results for "Titanium"
showing 10 items of 878 documents
Influence of titanium-vanadium alloys on cell morphology: electron microscopy and ESCA studies
2000
Titanium and its alloys provide optimum metallurgical properties for implants. The formation of an oxide layer favours compatibility with the adjacent hard and soft tissues. Research focuses on further optimizing the passive layer, particularly with respect to minimizing metal ion migration into the tissues. The present study concentrates on two alloys (Ti6A14V and Til.5A125V) coated with oxide layers generated by different techniques: thermal oxidation, anodic oxidation and sol-gel treatment. Only thermal oxidation fails to reduce surface and subsurface concentrations of vanadium, whereas other treatments avoid the element in the outermost surface areas of the alloys. Additionally, the the…
Pyrolysis study of sol-gel derived TiO2powders
2004
An amorphous TiO2 gel was obtained by hydrolysing titanium(IV) isopropoxide with a stoichiometric amount of water using SnCl2 as catalyst. In these operative conditions, a TiO2 gel matrix containing a lower fraction of organic residual was obtained with respect to samples prepared by previously modifying the titanium alkoxide precursor with chelating ligands. Dried gel powders were characterized by N2 adsorption analyses, FT-IR and XRD measurements. Thermogravimetric (TG) and differential thermal analysis (DTA) coupled with mass spectrometric (MS) and gas chromatographic (GC) measurements were performed in order to identify the organic products released from TiO2 gel pyrolysis. The Tg-MS se…
Extraction–Pyrolytic Method for TiO2 Polymorphs Production
2021
The authors thank V. Kuzovkov, A. Lushchik and M. Lushchik for many useful discussions. The research was (partly) performed in the Institute of Solid State Physics, University of Latvia ISSP UL. ISSP UL as the Center of Excellence is supported through the Framework Program for European universities Union Horizon 2020, H2020-WIDESPREAD-01–2016–2017-TeamingPhase2 under Grant Agreement No. 739508, CAMART2 project.
Influence of crystallinity and OH surface density on the photocatalytic activity of TiO2 powders
2014
Abstract The aim of the work was to study the influence of crystallinity and OH surface density on the photocatalytic activity of two commercial and two home-prepared TiO 2 powders. The samples were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TG) and electron paramagnetic resonance (EPR) measurements. The photoactivity of the powders was tested employing the photodegradation of 4-nitrophenol (4-NP) and the selective oxidation of 4-methoxybenzyl alcohol (4-MBA) to 4-methoxybenzaldehyde ( p -anisaldehyde) under UV irradiation. An anti-correlation between oxidant power and selectivity of the various samples was found. A higher rate of 4-NP degradation was exhibited by…
Improving the high temperature oxidation resistance of pure titanium by shot-peening treatments
2017
International audience; Shot-peening (SP) treatments have shown their capacity to improve the oxidation resistance of titanium and zirconium thanks to the large compressive stresses and the surface hardening induced by this mechanical process. However, shot-peening treatments can produce a surface chemical deposit, which can modify the high temperature oxidation resistance. Here, we study pure titanium samples shot-peened with different type of balls: tungsten carbide, alumina or glass. The oxidation behavior was studied at 700 °C in dry air by thermo gravimetric analysis for short isotherm oxidation periods up to 100 h. Also, long oxidation tests (3000 h) at 700 °C were performed with an i…
COMPUTER AIDED ENGINEERING FOR THERMO-MECHANICAL-METALLURGICAL ANALYSIS OF FORGING OPERATIONS OF TITANIUM ALLOYS
In this thesis a study on the forging processes of Ti-6Al-4V titanium alloy, with particular focus on the numerical applications and simulation design of hot forming methods, was done. The aim of this work is to collect all data concerning the material definition in terms of thermal, mechanical and microstructural properties of the selected alloy in order to filter all useful information to describe the behavior of the material under the characteristic conditions of the hot forging processes, taking into account both thermo-mechanical and metallurgical aspects involved during a such complex thermo-mechanical stage. Those information were collected and used to characterize the material prope…
Toward development of optical biosensors based on photoluminescence of TiO2 nanoparticles for the detection of Salmonella
2017
Quality control of food and agriculture production is an inseparable part of human safety and wellbeing. Salmonella infections belong to one of the most monitored pathogens in the world, therefore advanced determination of this pathogen can decrease the risks of human diseases caused by this microorganism. In this research we introduce a novel optical immunosensor for determination of Salmonella typhimurium. The immunosensor is based on Titanium dioxide (TiO2) nanoparticles deposited on glass substrates (glass/TiO2)center dot TiO2 nanoparticles exhibit an intense photoluminescence (PL) in the visible range of spectrum at room temperature. The direct immobilization of antibodies (anti-S-Ab) …
A study of electron transfer in Ru(dcbpy)2(NCS)2 sensitized nanocrystalline TiO2 and SnO2 films induced by red-wing excitation.
2008
Excited state dynamics and electron transfer from the Ru(dcbpy)2(NCS)2 (RuN3) sensitizer to semiconductor nanoparticles were studied using time-resolved femtosecond absorption spectroscopy. We found that excitation of the red wing of the absorption spectrum of the sensitizer populates the (3)MLCT state directly, both in solution and attached on semiconductor nanoparticle films. Electron injection is slowed down and becomes gradually less efficient as excitation moves towards red from the absorption maximum at 535 nm. At 675 nm the injection is non-exponential and characterized by 5, 30 and 180 ps time constants. The non-exponential electron injection observed is assigned to injection from a…
Promotion of osteogenic cell response using quasicovalent immobilized fibronectin on titanium surfaces: introduction of a novel biomimetic layer syst…
2012
Purpose Despite the undeniable potential of cell adhesion molecules such as fibronectin to support osteogenic cell responses and consecutive dental implant healing, the most beneficial mode of application onto titanium implant surfaces still requires investigation. Unspecific fibronectin adsorption on titanium dioxide (TiO2) surfaces can result in low-loading, high-desorption rates and protein–metal interactions with impaired biologic activity. The aim of the present study was to monitor the osteogenic cell responses (cell adhesion, proliferation, and differentiation) specifically to fibronectin biofunctionalized TiO2. Materials and Methods An innovative biomimetic streptavidin-biotin layer…