Presence Of Titanium Oxide Research Articles

How Plasmon Ag Nanoparticles can Enhance the Power Performance of a Thermoelectric Generator.

The development of wearable thermoelectric generators (wTEG) represents a promising strategy to replace batteries and supercapacitors required to supply electrical energy for portable electronic devices. However, the main drawback of wTEGs is that the thermal gradient between the skin and the ambient is minimal, reducing the power output produced by the generator. Therefore, it is necessary to improve the thermal management of wTEG in order to increase its efficiency. This work deals with the preparation of a thermoelectric generator that harnesses the plasmonic heating effect to enhance the thermal gradient of the final device. The thermoelectric layer is created through the in situ polymerization of terthiophene (3T) within a polyurethane matrix, utilizing silver (Ag) (I) and copper (II) perchlorate as oxidants. The plasmonic film, composed of Ag-NP (nanoparticles), is formed via photocatalytic reduction of silver nitrate in the presence of titanium oxide. These layers are then meticulously assembled to yield the hybrid plasmonic/thermoelectric generator.

Corrosion Resistance of Additive Manufactured Titanium Alloy Parts: The Effect of Recycled Powders

The possibility to reduce costs of the additive manufacturing (AM) technologies by using recycled powders is still an open question. The present paper aims to investigate the effect of using virgin and recycled powders on the corrosion resistance of Ti6Al4V titanium alloy additive manufactured parts. Although the study of the electrochemical behaviour of titanium parts produced by using AM is present in the literature, the corrosion resistance of samples manufactured using recycled powders is less investigated. This work would like to contribute to the deepening of this aspect. The experimental investigations have been carried out on as-built samples as well as on samples after mechanical polishing. The metallographic observations of additive manufactured samples showed a martensitic microstructure inside the prior β grain grew up as columnar structure. X-ray diffraction analysis revealed the presence of titanium oxide in rutile crystallographic phase. The electrochemical characterisation unveiled the lower corrosion resistance of the as-built additive manufactured components compared to the traditional counterpart. It also highlighted the effect due to the use of recycled powders when the bulk of the samples has been investigated.

Reactivity of Aluminum and Titanium Oxides under the Conditions of the Synthesis of Strontium and Barium Titanates in Water Fluid Media

Strontium and barium titanates deposited on a porous support (α-Al2O3) are synthesized by the treatment of previously deposited precursors (titanium oxide, strontium nitrate, or barium nitrite) in a water fluid medium at 400°C. The obtained samples are characterized by X-ray powder diffraction (XRD) analysis and scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) spectroscopy. It is found that, in the presence of titanium oxide, α-Al2O3 is partially hydrated to form basic aluminum hydroxide AlO(OH) (boehmite), which is not detected by XRD after the treatment of α-Al2O3 in a water fluid. SEM with EDX spectroscopy demonstrates that strontium ions under the conditions of the treatment in a water fluid preferably interact with titanium oxide to form SrTiO3, although the aluminum oxide content in the samples is much higher. The conditions are determined for obtaining systems with different spatial distributions of the supported component inside the granules of the support by varying the procedure of its preliminary impregnation with the titanium oxide precursor.

Understanding the effect of Al/Ti ratio on the tribocorrosion performance of Al/Ti co-doped diamond-like carbon films for marine applications

Al and Ti co-doped diamond-like carbon (DLC) films (Al/Ti-DLC) were prepared through hybrid ion beam deposition technique, in which the Al/Ti ratio was tailored from 6.6 to 2.0. The dependence of tribocorrosion performance of Al/Ti-DLC film on the Al/Ti ratio in 3.5 wt% NaCl solution was systematically explored. Results indicated that the existing states of Al and Ti dopants in the film were independent on the Al/Ti ratio, where Al existed in the form of oxidized state, while Ti mainly bonded with C and thus formed the titanium carbide following the presence of titanium oxide, leading to the increase of hardness and elastic modulus with the decrease of Al/Ti ratio. In particular, with reducing the Al/Ti ratio from 6.6 to 2.0, the tribocorrosion resistance was improved, mainly originating from the reduction of pure mechanical wear. However, EIS analysis further revealed that although the mechanical wear accelerated the electrochemical corrosion of Al/Ti-DLC films, the contribution of the synergistic effect between mechanical wear and corrosion attack to materials loss increased following the drop of Al/Ti ratio, due to the corrosion-induced wear rather than wear-induced corrosion. These outcomes not only shed light on the effect of Al/Ti ratio in the film on the tribocorrosion property but also guide the design of DLC films for marine applications.

In English

The present study aims to obtain the supported Ti-containing catalyst on a surface of stainless steel foil by low temperature ionic implantation method. The geometrical sizes of the implantation chamber allow one to synthesize composites with the maximum size of 30×30 cm. The shape and size of the catalysts provide an opportunity to use obtained samples for removal of harmful substances from both aqueous solutions and gas mixtures. A quantitative estimation of bond strength of the surface layer of the prepared composites was realized by the use of sclerometric method. It is shown that implantation of titanium ions on stainless steel foil provide significant increase in surface layer mechanical strength. The heat treatment of the sample leads to a decrease in this strength, but its value rests higher than that in initial support (stainless steel). The composition of samples surface and the effect of calcination temperature were determined by XRD, SAXS, SEM, AFM, and XPS. It is shown that after ionic implantation nanoscale layer of the implant on the surface of stainless steel was formed. Presence of titanium oxide, nitride and oxynitride was determined by XPS method. The high photocatalytic activity of this catalyst in the process of neutralizing benzene in aqueous solutions under irradiation with visible light, which significantly exceeds its activity under UV-radiation was shown. Increasing the calcination temperature leads to decreasing the samples activity and can be explained by the influence of the ratio between the nitride, oxynitride, and oxide phases of titanium. Exactly the presence of those phases on the surface explains its high activity in the degradation of benzene in aqueous solution under visible light irradiation. Thus, using of the obtained samples in the neutralization of aqueous benzene solutions under visible light irradiation is perspective from ecological point of view.

Influence of Carbon Content on Aluminothermic Reduction of Ilmenite During Hot Pressing

Al2O3-TiCN-Fe composites were successfully prepared by hot pressing using natural ilmenite, aluminum, and carbon. The process of aluminothermic reduction of ilmenite and the influence of carbon on the phase evolution, synthetic products, microstructure, and properties were investigated using x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and mechanical analysis. The XRD results showed that the reduction process of the FeTiO3-2Al system was a gradual deoxygenation process. In the FeTiO3-2Al-xC systems, carbon participates in the reduction reaction to form TiN, which gradually transforms to TiCN. The carbon content had a great influence on the presence of titanium oxides during the reaction. In addition, the grain size of Al2O3, TiCN, and Fe phases became smaller as the carbon content was increased. When the carbon content was 0.88 mol, the synthesized products achieved comprehensive mechanical properties, i.e., bending strength and Vickers hardness of 375 MPa and 15.5 GPa, respectively.

Peptides of human body fluids as sensors of corrosion of titanium to titanium dioxide. SERS application

Technical titanium (Ti) and its alloys are the most commonly used biomaterials. Therefore, it is important to know how the corrosion of a metal device implanted in the human body causes clinically significant problems and it is necessary to develop an in vivo method to examine the condition of the implant. Raman spectroscopy offers the possibility of inserting a Raman probe into the vicinity of the implant to determine the surface condition of the implant and the content of titanium dioxide (TiO2) in the surrounding area. For this purpose, trace elements in human body fluids; e. g., peptides, can be used. For the above reasons, in this work the surfaces of Ti plate and TiO2 (anatase and rutile) nanostructures (TiO2NPs) were characterized using ultraviolet–visible (UV–Vis), Fourier-transform infrared (FT-IR), Raman, and X-ray photoelectron (XPS) spectroscopies as well as scanning electron microscope with energy dispersive X-ray (SEM-EDS) and X-ray powder diffraction (XRD). These metal surfaces were used as highly sensitive, uniform, and reproducible sensors of the natural ligand (bombesin, BN) of some types of metabotropic seven transmembrane G protein-coupled superfamily receptors (GPCRs), which are over-express on the surface of many malignant tumors and are present in human body fluids. Surface-enhanced Raman scattering (SERS) was used to monitor the geometry of adsorbate, to separate, enrich, and detect a variety of BN fragments in a physiological environment and to determine the type of surface (Ti vs TiO2). Our work extends the use of SERS to monitor the implant surface and the presence of titanium oxide in the surrounding environment as well as the use of Ti/TiO2NPs as potential receptor-positive cancer markers or the use of peptides to inhibit the photocatalitic properties of anatase TiO2NPs.

Laser surface textured titanium alloy (Ti–6Al–4V): Part 1 – Surface characterization

In the present study, a detailed study of the characterization of laser-surface textured titanium alloy (Ti–6Al–4V) with line and dimple geometry developed by using an ArF excimer laser operating at a wavelength of 193nm with a pulse length of 5ns is undertaken. The characterization of the textured surface (both the top surface and cross section) is carried out by scanning electron microscopy, electron back scattered diffraction (EBSD) technique and X-ray diffraction techniques. There is refinement of microstructure along with presence of titanium oxides (rutile, anatase and few Ti2O3 phase) in the textured surface as compared to as-received one. The area fractions of linear texture and dimple texture measured by image analysis software are 45% and 20%, respectively. The wettability is increased after laser texturing. The total surface energy is decreased due to linear (29.6mN/m) texturing and increased due to dimple (67.6mN/m) texturing as compared to as-received Ti–6Al–4V (37mN/m). The effect of polar component is more in influencing the surface energy of textured surface.

Microstructure and mechanical properties of surface treated cast titanium with Nd:YAG laser

ObjectiveTo investigate the effect of laser surface treatment of cast titanium alloy on microstructure and mechanical properties. MethodsDumbbell- and plate-shaped cast titanium specimens were prepared for mechanical testing and microstructure analysis. After the cast surfaces of each specimen were laser-treated using a dental Nd:YAG laser machine at 240V and 300V with and without argon gas shielding, tensile testing and microstructure analysis were conducted. Hardness depth profiles were also made from the cross-section of laser-treated cast specimens. Microstructural and chemical analysis were performed by means of the SEM, XRD, AES and WDS. ResultsThe results of tensile testing and Vickers hardness depth profiling showed that laser treatment improved the mechanical properties. Bulk microstructure of as-cast titanium was mainly composed of α-grains with acicular and widmanstatten patterns. The laser melted zone was characterized by columnar beta grains. When the emission voltage of laser increased to 300V, a larger grain size was promoted. The XRD analysis indicated that the beta phase formation was clearly noticeable after laser surface treatment. Supplementary marked peaks of the TiO, TiO2 and Ti2N were detected without argon gas shielding. When argon shielding gas was used, the presence of titanium oxide was significantly reduced and the peaks of titanium nitride disappeared. SignificanceLaser treatment on cast titanium surfaces showed significant enhancement of mechanical properties and modification of microstructures, and therefore could produce reliable titanium metal frameworks for dental prostheses.

The influence of TiO2 nano-particles on bond strength of cold roll bonded aluminum strips

Abstract In the present work, cold roll bonding (CRB) process characteristics of AA1050 strips, such as bond strength, threshold deformation, undulation of peeling force, and peeled surface in the presence of TiO 2 nano-particles were carried out and compared to those of aluminum strip without particles. The bond strength was evaluated by the peeling test. The results indicated that when the reduction in thickness was increased, the peeling force of AA1050 strips was enhanced. It was found that the presence of TiO 2 nano-particles reduces the bond strength of layered strips when compared to layered pure aluminum for the same reduction in thickness applied through CRB process. When the reduction in thickness was increased, the undulation of average peeling force values was increased at constant particles content. Also, the strips without particles had lower undulation value as compared to the strips with titanium oxide particles. In addition, in the presence of titanium oxide, when the particles content was increased, the undulation of average peeling force values was decreased at constant reduction in thickness. On the other hand, by increasing the particles content, the average slope of bond strength curves was decreased and the threshold deformation was increased. Finally, it was found that the bond strength of AA1100/alumina/AA1100 strips was much more than that of AA1050/titanium oxide/AA1050. This was attributed to both the metal and particle type.

TiO and VO broad band absorption features in the optical spectrum of the atmosphere of the hot-Jupiter HD 209458b

Context. The presence of titanium oxide (TiO) and vanadium oxide (VO) gas phase species is searched for in the atmosphere of the hot Jupiter HD 209458b. Aims. We compared a model for the planet’s transmitted spectrum to multi-wavelength eclipse-depth measurements (from 3 000 to 10 000 A), obtained by Sing et al. (2008a) using archived HST-STIS time series spectra. We make use of these observations to search for spectral signatures from extra absorbers in the planet a tmosphere between 6 000 and 8 000 A. Methods. Along with sodium depletion and Rayleigh scattering recently published for this exoplanet atmosphere, an extra absorb er of uncertain origin, redward of the sodium lines, resides in the atmosphere of the planet. Furthermore, this planet has a stratosphere experiencing a thermal inversion caused by the capture of optical stellar flux by absorbers that resides at altitude. Rec ent models have predicted that the presence of TiO and VO in the atmosphere of HD 209458b may be responsible for this temperature inversion. Although no specific TiO and VO spectral band head signatures have been identified unambiguously in the observed spectrum , we suggest here that the opacities of those molecules are possi ble candidates to explain the remaining continuous broad band absorption observed between 6 200 and 8 000 A. To match reasonably well the data, the abundances of TiO and VO molecules are evaluated from ten to one thousand times below solar. This upper limit result is in agreement with expected variations with altitude due to depletion effects such as condensation. Results.

In situ Radical Copolymerization in Presence of Surface‐Modified TiO2 Nanoparticles: Influence of a Double Modification on Properties of Unsaturated Polyester (UP) Nanocomposites

In the preparation of nanocomposites, there is competition between the dispersion of nanoparticles and the formation of agglomerates. In this study, radical copolymerization of ethyl acrylate and methyl methacrylate initiated by 2,2‐azobis (isobutyro) nitrile (AIBN) was performed, in the presence of titanium oxide (TiO2) nanoparticles modified in a new approach; a good dispersion of the nanoparticles in the unsaturated polyester (UP) matrix was obtained. The TiO2 nanoparticles were exposed to 3‐(methacryloxy) propyl trimethoxy silane as the coupling agent. The presence of coupling agent‐grafted TiO2 nanoparticles in the copolymerization process resulted in the formation of a polymeric layer on the surface of the TiO2 nanoparticles (doubly modified‐TiO2). The grafting of coupling agent molecules and consequently copolymer macromolecular chains onto the surface of TiO2 nanoparticles was investigated using Fourier transform infrared (FTIR) analysis. It found that the formation of an acrylate layer on the surface of nanoparticles was successful. Then, unsaturated polyester (UP)/TiO2 nanocomposites were prepared. The morphology was studied using transmission electron microscopy (TEM). Mechanical properties and ultraviolet visible (UV/VIS) spectroscopy of various samples, including the doubly modified‐TiO2 nanoparticles, with different nanoparticle inclusions and the unmodified‐TiO2 nanoparticles, were also investigated. The results showed the doubly modified‐TiO2 nanoparticles, compared to those of unmodified‐TiO2, had better nanoparticle dispersion causing improvement in the mechanical properties and UV shielding.

Non-Thermal Plasma degradation of wastewater in presence of titanium oxide by gliding arc discharge

Degradation of polluted plastic and rubber wastewater using the plasmachemical and plasmacatalytic process has been studied by non-thermal gliding arc technique. The gaseous species formed in the discharge, and especially the °OH radicals, induced strong oxidising effects in the target solution. The treatment with TiO2 photo-catalyst led to a degradation of 80% in 60 min, a decrease of turbidity of 92% and enabled the wastewater to become biodegradable in less than 30 min. In both cases of treatment with and without catalyst, the plasmageneous process appears to give once more satisfactory results in the field of wastewaters degradation.

Brilliant yellow dye immobilized on silica and silica/titania based hybrid xerogels containing bridged positively charged 1,4-diazoniabicyclo[2.2.2]octane: Preparation, characterization and electrochemical properties study

Silica and silica/titania based hybrid xerogels containing the double charged 1,4-diazoniabicyclo[2.2.2]octane group bonded in a bridged way were obtained. The hybrids were characterized by infrared spectroscopy and CHN analyses for the identification and determination of organic content. N 2 adsorption–desorption isotherms and SEM were applied to study morphological and textural aspects. The hybrid materials presented anion-exchange properties that allowed their use as adsorbent for brilliant yellow anionic dye. These modified materials were used to prepare carbon paste electrodes for cyclic voltammetric measurements, where the brilliant yellow, for the first time, was applied as electroactive species. The pH solution has no effect on the anodic peak potential and anodic peak current in the values range between 2.0 and 7.0. The electrode response was invariant under various oxidation–reduction cycles showing that the system is chemically very stable. Considering that the presence of titanium oxide in the xerogel enhanced the conductivity, a carbon paste electrode of the (R 2dabco)BY/SiO 2/TiO 2 material was prepared to study the electrocatalytic oxidation of ascorbic acid by cyclic voltammetric and chronoamperometric techniques.

Photocatalytic decoloration of Coomassie Brilliant Blue with titanium oxide

Coomassie Brilliant Blue dye was subjected to UV radiation in the presence of titanium oxide. The change in the color of the dye was monitored spectrophotometrically. The apparent rate of decolorization was calculated from the observed data and was found to fit the first order equation. The added amounts of Zn 2+ ions caused a decrease in dye decoloration. A plausible explanation involving the radical initiated reaction is forwarded. Langmuir–Hinshelwood model was also used to describe the photocatalytic kinetics of the dye.

Reaction of titanium beryllide with water vapor

Titanium beryllides such as Be 12Ti are considered to become promising alternatives of beryllium as the neutron multiplier. Thus, the authors investigated the reactivity of Be 12Ti with water vapor. In the experiments, the Be 12Ti sample was exposed to a gas containing water vapor of 10,000 ppm at the temperature of as high as 1000 °C. Chaotic breakaway reactions were not observed for the Be 12Ti sample, and the amount of hydrogen generated was found to be lower in comparison with beryllium. Therefore, it can be said that titanium Be 12Ti has less reactivity with water vapor, which is a great merit for the neutron multiplier. In order to clarify the mechanism underlying the high tolerance to oxidation by water vapor, the authors observed the surface of the sample exposed to water vapor using digital electron microscope and scanning electron microscope. The results indicate that an oxidized layer was produced on the surface of the sample. Furthermore, X-ray diffraction analysis was carried out, which indicates that beryllium oxide (BeO) is present on the surface. However, the presence of titanium oxides or complex oxides of titanium and beryllium were not identified.

Reaction of Titanium Beryllide with Water Vapor

Abstract Titanium beryllides such as Be 12 Ti are considered to become promising alternatives of beryllium as the neutron multiplier. Thus, the authors investigated the reactivity of Be 12 Ti with water vapor. In the experiments, the Be 12 Ti sample was exposed to a gas containing water vapor of 10,000 ppm at the temperature of as high as 1000 °C. Chaotic breakaway reactions were not observed for the Be 12 Ti sample, and the amount of hydrogen generated was found to be lower in comparison with beryllium. Therefore, it can be said that titanium Be 12 Ti has less reactivity with water vapor, which is a great merit for the neutron multiplier. In order to clarify the mechanism underlying the high tolerance to oxidation by water vapor, the authors observed the surface of the sample exposed to water vapor using digital electron microscope and scanning electron microscope. The results indicate that an oxidized layer was produced on the surface of the sample. Furthermore, X-ray diffraction analysis was carried out, which indicates that beryllium oxide (BeO) is present on the surface. However, the presence of titanium oxides or complex oxides of titanium and beryllium were not identified.

Titanium Oxide (TiO2) Catalysed One-Step Beckmann Rearrangement of Aldehydes and Ketones in Solvent Free Conditions

In the presence of titanium oxide (TiO2) and without any additional organic solvents, Beckmann rearrangement of several ketones and aldehydes was performed in good yield.

Influence of the presence of titanium oxide on the formation of pyrochlore phase in ferroelectric strontium bismuth tantalate ceramics

The effects of addition of TiO2 on the formation of pyrochlore phase and dielectric properties of ferroelectric SrBi2Ta2O9 have been investigated. When the content of Ti02 is less than 10 mol%, no secondary phases are produced, and SrBi2Ta2O9-TiO2 solid solutions are formed. However, with TiO2 content ⩾20 mol%, a pyrochlore phase is produced. Raising the content of TiO2 in starting materials significantly increases the amounts of pyrochlore phase, and reduces the initial temperature for the formation of pyrochlore phase. The existence of TiO2 also decreases the thermal stability of SrBi2Ta2O9, causing the decomposition of SrBi2Ta2O9to take place at lower temperatures. Furthermore, the presence of TiO2 reduces the dielectric constants as well as remnant polarization of formed ceramics.

Chemical vapour deposition of Al 2O 3 on TiO

This paper is a study of the phase content and morphology of Al 2O 3 grown by the AlCl 3/H 2/CO 2 process on a chemical vapour deposition (CVD) TiO layer. The results were compared with the results of CVD of Al 2O 3 on Ti 2O 3, Ti 3O 5 and TiO 2 from an earlier investigation. The reason for this study is that it has been suggested that the presence of titanium oxides on a TiC surface promotes the formation of α- Al 2 O 3 resulting in inferior wear properties of cemented carbide cutting tools. The present investigation showed that α- Al 2 O 3 was the only aluminium oxide polymorph obtained on intact layers of TiO as well as of Ti 2O 3, Ti 3O 5 and TiO 2. The layers consisted of well-shaped crystallites with many cracks. The formation of titanium oxides upon oxidation of a TiC surface in a H 2O H 2 atmosphere was studied thermodynamically. At a pressure of 6.7 × 10 3 Pa and very low H 2O concentrations TiO was obtained, while higher concentrations yielded both Ti 2O 3 and Ti 3O 5.