scholarly journals FUNCTIONAL NANOSTRUCTURED MATERIALS BASED ON TITANIUM DIOXIDE FOR USE IN ORTHOPEDIC DENTISTRY

2020 ◽  
Vol 16 (1) ◽  
pp. 171-177
Author(s):  
Oksana Shulyatnikova ◽  
Gennadiy Rogozhnikov ◽  
Svetlana Porozova ◽  
A. Rogoznikov ◽  
Elena Leushina
Keyword(s):  
Titanium Dioxide ◽  
Surface Layer ◽  
Oxide Layer ◽  
Adhesion Force ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Ceramic Coatings ◽  
Functional Coatings ◽  
Functional Surface ◽  
Chemical Impurities

Subject. The creation of functional ceramic coatings based on titanium dioxide for the manufacture of orthopedic structures, including dental implants and systems for osteosynthesis, helps to prevent possible complications during dental surgical and orthopedic treatment by improving the processes of osseointegration. The goal is to develop domestic proprietary technology for producing nanopowders and functional coatings based on titanium dioxide, free of chemical impurities, which can be used in the practice of orthopedic dentistry for the construction of dental and maxillary prostheses, as well as implant systems. Methodology. The authors developed and proposed a method for applying to medical devices made of titanium, a nanostructured surface layer of titanium dioxide. To provide an evidence base for the advantages of using the proposed titanium dioxide coating, an experimental study was made of its chemical uniformity and freedom from impurities, as well as an assessment of the adhesion force between the oxide layer deposited by titanium dioxide in the anatase phase and the surface of the titanium support. Results. During Raman spectroscopy, titanium dioxide nanopowder did not detect extraneous chemical impurities. According to the results of the method of thermal desorption of nitrogen, the specific surface of the titanium dioxide powder was 67-70 m2 / g, and the average calculated particle size was 20-22 nm. It was shown by optical microscopy that the average thickness of the oxide layer (rutile phase) is 15 ± 5 μm, anatase is 70 ± 10 μm, the adhesion force between the oxide layer (rutile phase) and the titanium base is 6.3 ± 0.1 MPa, at applying anatase - 4.9 ± 0.1 MPa. In the study of the adhesion force of a functional titanium dioxide coating with a titanium base, it was found that the onset of peeling occurs at a load of 8.6 N. Conclusions. Studies of a highly developed functional surface layer of nanostructured titanium dioxide indicate the wide possibilities of its use in the practice of a dentist.

scholarly journals Unexpected Link between the Template Purification Solvent and the Structure of Titanium Dioxide Hollow Spheres

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 112
Author(s):  
Tamás Gyulavári ◽  
Kata Kovács ◽  
Klára Magyari ◽  
Kornélia Baán ◽  
Anna Szabó ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Phase Composition ◽  
Anatase Phase ◽  
Hollow Spheres ◽  
Rutile Phase ◽  
Carbon Sphere ◽  
Carbon Spheres ◽  
Carbonate Species ◽  
Determining Factor

Carbon spheres were applied as templates to synthesize titanium dioxide hollow spheres. The templates were purified with either ethanol or acetone, and the effects of this treatment on the properties of the resulting titania were investigated. The photocatalytic activity of the catalysts was measured via the decomposition of phenol model pollutant under visible light irradiation. It was found that the solvent used for the purification of the carbon spheres had a surprisingly large impact on the crystal phase composition, morphology, and photocatalytic activity. Using ethanol resulted in a predominantly rutile phase titanium dioxide with regular morphology and higher photocatalytic activity (r0,phenol = 3.9 × 10−9 M∙s−1) than that containing mainly anatase phase prepared using acetone (r0,phenol = 1.2 × 10−9 M∙s−1), surpassing the photocatalytic activity of all investigated references. Based on infrared spectroscopy measurements, it was found that the carbon sphere templates had different surface properties that could result in the appearance of carbonate species in the titania lattice. The presence or absence of these species was found to be the determining factor in the development of the titania’s properties.

Effect of Iron and Vanadium on the Phase Transition of Titanium Dioxide Obtained by Polymeric Precursor Method

2016 ◽  
Vol 881 ◽  
pp. 18-23
Author(s):  
Eduardo Felipe de Carli ◽  
Maycon dos Santos ◽  
Natali Amarante da Cruz ◽  
Daniela Cristina Manfroi ◽  
Jusinei Meireles Stropa ◽  
...  
Keyword(s):  
Phase Transition ◽  
Titanium Dioxide ◽  
Phase Formation ◽  
Anatase Phase ◽  
Synthesis Method ◽  
Rutile Phase ◽  
Polymeric Precursor Method ◽  
Polymeric Precursor ◽  
Precursor Method ◽  
Powder Samples

The titanium dioxide phase formation is dependent on the synthesis method, temperature of calcination and modifiers insertion. By using chemical methods, such as Polymeric Precursor Method, the organic impurities or extrinsic defects caused by doping play an important rule on the formation of precursor structure before the phase crystallization above 500 oC. Some dopants can change the decomposition mechanism of the precursor, which affects the anatase-rutile phase transition. In this work, the Polymeric Precursor Method was used to synthesize titanium dioxide powder samples in order to investigate the effects of iron (III) and vanadium (V) dopants on the phase formation. Through thermal analysis of polymeric precursors and X-ray diffractometry for calcined powder samples it was possible to show the existence of antagonistic effects for both investigated dopants. While the iron doping reduces the anatase phase tetragonality and delays the rutile phase conversion, the vanadium one changes the mechanism of decomposition of polymeric precursor and leads to more amount of rutile phase.

The Photocatalytic Properties of Br-Doped Titania Nanotube Arrays and its Application in Degradation of Sugar Wastewater

2013 ◽  
Vol 641-642 ◽  
pp. 11-17 ◽  
Author(s):  
Zhi Peng Meng ◽  
Fu Xin Zhong ◽  
Dan Yu Wang ◽  
Zhong Ming Zhang ◽  
Hua Ying Li ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Degradation ◽  
Uv Light ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Photocatalytic Properties ◽  
Nanotube Arrays ◽  
Illumination Time ◽  
Novel Approach ◽  
Titanium Dioxide Nanotube Arrays

This paper presents a novel approach for preparing titanium dioxide nanotube arrays (TNTs) loaded with highly dispersed Br through an ultrasound aided photochemical route. The content of Br doped on the arrays was controlled by changing the concentration of NaBr and the ultrasound time. The Br doped TiO2nanotube arrays were characterized by SEM, XRD and UV–Vis spectrum. Doping the bromine did not basically affect the morphology of the surface of the TNTs, but part of the anatase phase transformed into rutile phase, which led to the formation of the mixed crystal and increased the photocatalytic activity. The results showed that Br doping significantly enhanced the photocatalytic degradation rate of titanium dioxide nanotube arrays under UV-light irradiation. The main factors which affected photocatalytic degradation of sugar wastewater were the illumination time and pH. The results showed that the longer the exposure time was, the initial pH of wastewater was more favorable to photocatalytic degradation of the sugar wastewater for the Br-TiO2nanotube arrays, and compared to undoped TiO2nanotube arrays Br doped TiO2nanotube arrays had better photocatalytic properties.

Structural and Thermal Studies of Titanium Dioxide Gel Modified with Anatase Isostructural Zircon Silicate

2018 ◽  
Vol 930 ◽  
pp. 73-78
Author(s):  
Eduardo Felipe de Carli ◽  
Natali Amarante da Cruz ◽  
Hiana Muniz Garcia ◽  
Jusinei Meireles Stropa ◽  
Lis Regiane Vizolli Favarin ◽  
...  
Keyword(s):  
Phase Transition ◽  
Titanium Dioxide ◽  
Rietveld Method ◽  
Anatase Phase ◽  
Sol Gel ◽  
Thermal Studies ◽  
Rutile Phase ◽  
Structural Rearrangements ◽  
X Ray Diffraction ◽  
X Ray

Important changes in anatase crystal structure are responsible for the consequent anatase-to-rutile phase transition in titanium dioxide powders. In order to investigate several structural rearrangements occurring in anatase phase obtained by hydrolysis-based method such as Sol-Gel method the X-ray diffraction techniques followed by Rietveld method seems to better approach. Several alterations in anatase lattice parameters can occur by doping insertion and the investigation of isostructural zircon silicate can provide interesting ones. In the present paper, the monitoring of anatase structure reordering and the consequent anatase-to-rutile phase transition along the thermal treatment up to higher temperatures were monitored carrying out DSC and XRD characterizations. The insertion of 6 mol% of zircon silicate leads to the fully anatase stabilization up to 900 °C due the control of ordering process, even that a continuous increasing in anatase tetragonality is present during the entire process. We can conclude the reconstructive anatase-to-rutile phase transition is delayed to very higher temperatures can consequence of more stable cross-linked metal oxide bond in anatase phase.

Characteristics of Photocatalytic Titania Fabricated by Anodization

2005 ◽  
Vol 475-479 ◽  
pp. 4153-4156 ◽  
Author(s):  
J.H. Lee ◽  
H.J. Oh ◽  
Y. Jeong ◽  
Y.J. Lee ◽  
J.S. Kim ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Surface Layer ◽  
Acid Solution ◽  
Oxide Layer ◽  
Degradation Rate ◽  
Anodic Film ◽  
Aniline Blue ◽  
Tio2 Films ◽  
Photocatalytic Efficiency ◽  
Chemical States

The anodic titanium dioxide (TiO2) films for photocatalyst were prepared by anodization in acid solution. The characteristics of surface layer and the photocatalytic efficiency of the anodic film have been investigated. The chemical states of anodic film were analyzed using XPS, and the photocatalytic efficiency was evaluated by the degradation rate of aniline blue. From XPS results the component elements of the electrolyte, P and S, were observed in the anodic film, which were incorporated from the electrolyte into the oxide layer during anodization. The porous TiO2 film exhibited high photocatalytic efficiency for degradation of aniline blue.

Effect of the Iron Doping on the Thermal Decomposition of the Polymeric Precursor for the Titanium Dioxide Powder Synthesis

2014 ◽  
Vol 798-799 ◽  
pp. 211-216 ◽  
Author(s):  
Silvanice A. Lopes ◽  
Natali A. Cruz ◽  
Daniela C. Manfroi ◽  
Rafael Gomes Dias ◽  
Margarete S. Silva ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermal Decomposition ◽  
Titanium Dioxide ◽  
Anatase Phase ◽  
Visible Region ◽  
Rutile Phase ◽  
Polymeric Precursor Method ◽  
Polymeric Precursor ◽  
Powder Synthesis ◽  
Precursor Method

The Polymeric Precursor Method has proved suitable for synthesizing reactive powders using low temperatures of calcination, especially when compared with conventional methods. However, during the thermal decomposition of the polymeric precursor the combustion event can be releases an additional heat that raises the temperature of the sample in several tens of degrees Celsius above the set temperature of the oven. This event may be detrimental to some material types, such as the titanium dioxide semiconductor. This ceramic material has a phase transition at around 600 ° C, which involves the irreversible structural rearrangement, characterized by the phase transition from anatase to rutile TiO2 phase. The control of the calcination step then becomes very important because the efficiency of the photocatalyst is dependent on the amount of anatase phase in the material. Furthermore, use of dopant in the material aims to improve various properties, such as increasing the absorption of radiation and in the time of the excited state, shifting of the absorption edge to the visible region, and increasing of the thermal stability of anatase. In this work, samples of titanium dioxide were synthesized by the Polymeric Precursor Method in order to investigate the effect of Fe (III) doping on the calcination stages. Thermal analysis has demonstrated that the Fe (III) insertion at 1 mol% anticipates the organic decomposition, reducing the combustion event in the final calcination. Furthermore, FTIR-PAS, XRD and SEM results showed that organic matter amount was reduced in the Fe (III)-doped TiO2 sample, which reduced the rutile phase amount and increased the reactivity and crystallinity of the powder samples.

scholarly journals PENGARUH PELARUT TERHADAP KARAKTERISTIK NANOPARTIKEL TITANIUM DIOKSIDA (TiO2)

2017 ◽  
Vol 17 (1) ◽  
pp. 26
Author(s):  
Atik Setyani ◽  
Emas Agus Prastyo Wibowo
Keyword(s):  
Titanium Dioxide ◽  
Powder Diffraction ◽  
Titanium Dioxide Nanoparticles ◽  
Anatase Phase ◽  
Sol Gel ◽  
Rutile Phase ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
X Ray ◽  
Tio2 Anatase

PENGARUH PELARUT TERHADAP KARAKTERISTIK NANOPARTIKEL TITANIUM DIOKSIDA (TiO2) ABSTRAK Tujuan penelitian ini adalah untuk membandingkan jenis pelarut dalam proses pembentukan nanopartikel titanium dioksida dengan metode sol gel. Hasil karakterisasi dengan X-Ray Diffraction (XRD) menunjukkan bahwa penggunaan pelarut berpengaruh terhadap kristalinitas dan fasa material yang terbentuk. Berdasarkan Joint Committee on Powder Diffraction Standards (JCPDS) card nomor 84-1286 menunjukkan difraktogram nano TiO2 hasil sintesis sebagian besar merupakan fasa anatas. Hal ini terlihat dari nilai 2 teta yang diperoleh yaitu 24,45˚; 47,29˚; 53,18˚; 61,64˚ untuk fasa anatas dan 54,65˚; 74,16˚ untuk fasa rutil. Hanya saja persentase fasa anatas pada nano TiO2 menggunakan pelarut metanol lebih besar jika dibandingkan dengan hasil nano TiO2 dengan pelarut etanol. Berdasarkan perhitungan ukuran partikel nano TiO2 menggunakan persamaan Debye- Scherer didapatkan ukuran nano TiO2 menggunakan metanol sebesar 13.78 nm sedangkan  nano TiO2 menggunakan etanol sebesar 34.26 nm. Kata Kunci: Pelarut, sol-gel, titanium dioksida   EFFECT OF SOLVENTS ON THE CHARACTERITICS OF NANOPARTICLES TITANIUM DIOXIDE (TiO2) ABSTRACTThe purpose of this study was to compare the type of solvent in the process of formation of titanium dioxide nanoparticles with sol gel method. X-Ray Diffraction (XRD) characterization results indicate that the use of solvent effect on crystallinity and phase material formed. Based Joint Committee on Powder Diffraction Standards (JCPDS) 84-1286 card numbers show diffractogram nano TiO2 synthesized largely a anatas phase. This can be seen from a value of 2 theta obtained by the 24,45˚; 47,29˚; 53,18˚; 61,64˚ to phase anatas and 54,65˚; 74,16˚ for rutile phase. Only a small percentage of the nano TiO2 anatase phase using methanol solvent is greater when compared with the results of nano TiO2 with ethanol. Based on the calculation of nano TiO2 particle size using equation Debye- Scherer obtained nanosized TiO2 using methanol amounted to 13.78 nm while the nano TiO2 using ethanol amounted to 34.26 nm. Keywords: Solvent, sol-gel, titanium dioxide

Unconventional Low-Temperature Luminescence Kinetics in Micro- and Nanopowders of the Anatase Phase of Titanium Dioxide

JETP Letters ◽  
2020 ◽  
Vol 112 (8) ◽  
pp. 471-477
Author(s):  
V. S. Krivobok ◽  
A. V. Kolobov ◽  
S. E. Dimitrieva ◽  
D. F. Aminev ◽  
S. I. Chentsov ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Low Temperature ◽  
Anatase Phase ◽  
Luminescence Kinetics

scholarly journals Osseointegrating and phase-oriented micro-arc-oxidized titanium dioxide bone implants

2021 ◽  
Vol 19 ◽  
pp. 228080002110068
Author(s):  
Hsien-Te Chen ◽  
Hsin-I Lin ◽  
Chi-Jen Chung ◽  
Chih-Hsin Tang ◽  
Ju-Liang He
Keyword(s):  
Titanium Dioxide ◽  
High Surface ◽  
Cell Activity ◽  
Active Surface ◽  
Rutile Phase ◽  
Hydroxyl Groups ◽  
Bone Implant ◽  
Implant System

Here, we present a bone implant system of phase-oriented titanium dioxide (TiO2) fabricated by the micro-arc oxidation method (MAO) on β-Ti to facilitate improved osseointegration. This (101) rutile-phase-dominant MAO TiO2 (R-TiO2) is biocompatible due to its high surface roughness, bone-mimetic structure, and preferential crystalline orientation. Furthermore, (101) R-TiO2 possesses active and abundant hydroxyl groups that play a significant role in enhancing hydroxyapatite formation and cell adhesion and promote cell activity leading to osseointegration. The implants had been elicited their favorable cellular behavior in vitro in the previous publications; in addition, they exhibit excellent shear strength and promote bone–implant contact, osteogenesis, and tissue formation in vivo. Hence, it can be concluded that this MAO R-TiO2 bone implant system provides a favorable active surface for efficient osseointegration and is suitable for clinical applications.

scholarly journals Preparation and High-Throughput Testing of TiO2-Supported Co Catalysts for Fischer‒Tropsch Synthesis

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 352
Author(s):  
Christian Schulz ◽  
Peter Kolb ◽  
Dennis Krupp ◽  
Lars Ritter ◽  
Alfred Haas ◽  
...  
Keyword(s):  
High Throughput ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Tropsch Synthesis ◽  
Performance Tests ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Co Catalysts ◽  
Impregnation Technique ◽  
Co Conversion

A series of Co/TiO2 catalysts was tested in a parameters field study for Fischer‒Tropsch synthesis (FTS). All catalysts were prepared by the conventional impregnation technique to obtain an industrially relevant Co content of 10 wt % or 20 wt %, respectively. In summary, 10 different TiO2 of pure anatase phase, pure rutile phase, as well as mixed rutile and anatase phase were used as supports. Performance tests were conducted with a 32-fold high-throughput setup for accelerated catalyst benchmarking; thus, 48 experiments were completed within five weeks in a relevant operation parameters field (170 °C to 233.5 °C, H2/CO ratio 1 to 2.5, and 20 bar(g)). The most promising catalyst showed a CH4 selectivity of 5.3% at a relevant CO conversion of 60% and a C5+ productivity of 2.1 gC5+/(gCo h) at 207.5 °C. These TiO2-based materials were clearly differentiated with respect to the application as supports in Co-catalyzed FTS catalysis. The most prospective candidates are available for further FTS optimization at a commercial scale.

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