Oxide Anatase Research Articles

Comparative Analysis of Biodiesel Produced from Blends of Palm Kernel Shell and Cocoa Pods Oils with Conventional Diesel Fuel: Characterizations, FTIR, GC-MS, XRD and SEM Analysis of the Nano Catalyst

The uncertainty of predicting the conditions of bio oils for the production of quality biofuels and reusability of catalyst, saving cost of production and time, make characterization of the oils/catalyst imperative. Characterization of bio oils, extracted from palm kernel shell and cocoa pods, the blends, catalyst and biodiesel produced therefrom is investigated. A maximum biodiesel yield of 76.05% was obtained at optimal conditions. Titanuim oxide used proved to be efficient catalyst for converting the oil blends to biodiesel. The established results obtained show kinematic viscosity of 5.65 – 7.78 mm2s-1 @ 40 oC, density of 0.8428 – 0.8642 kg/m3, cloud point of 4.48 – 6.48 oC, fire point of 108 – 150 oC, cetane index of 37.78 – 30.13, acid value of mg KOH/g, API gravity of 32.89 – 29, anicidine point of 50 – 46 oC etc. All the values fell within the recommended ASTM and EN standards. The GC-MS, XRD, EDX, SEM, and FTIR analyses carried out to evaluate the quality of the sample with respect to deterioration, gave an ester percentage of 99.9% for the bio-oil and biodiesel, which is within the minimum standard range of not less than 96.5% recommended. The GC-MS of the blended oil shows that the most prevalent fatty acids identified amongst 13 other distinct compounds were methyl linolenate, methyl palmitate, methyl oleate and methyl eicosadinoate with percentage concentrations of 63.03, 26.9, 8.1 and 2% respectively. The XRD analysis confirmed the titanium oxide anatase structure with a peak of 25.4 degrees. The SEM analysis shows high porosity with high specific surface area of the catalyst at magnification of 80 – 269μm; and the FTIR analysis revealed that the functional groups for the bio-oil and blended biodiesel were in range.

Titanium (IV) oxide anatase nanoparticles as vectors for diclofenac: assessing the antioxidative responses to single and combined exposures in the aquatic macrophyte Egeria densa

Titanium dioxide, frequently used in commonplace products, is now regularly detected in aquatic environments. Understanding its toxic effects on native biota is essential. However, combined toxicity with commonly occurring pollutants, such as the pharmaceutical diclofenac, may provide more insight into environmental situations. Therefore, the present study aimed to evaluate the effects of titanium dioxide and diclofenac, individually and combined, on the macrophyte Egeria densa. Diclofenac uptake and removal by the macrophyte were assessed. Diclofenac and titanium dioxide were mixed prior to exposure to allow binding, which was assessed. Toxicity of the individual compounds and the combination was evaluated by assaying enzymes as bioindicators of biotransformation and the antioxidative system. Cytosolic glutathione S-transferase and glutathione reductase activities were increased by diclofenac, titanium dioxide, and the combination. Both enzymes’ activities were more significantly elevated by diclofenac and the combination than nanoparticles alone. Microsomal glutathione S-transferase was unaffected by diclofenac exposure but inhibited with titanium dioxide and the mixture. Diclofenac elicited the most significant response. Based on the data, the cytosolic enzymes effectively prevented damage.

Photocatalytic, phosphorus‐doped, anatase oxide layers applicable to titanium implant alloys

Titanium alloys provide excellent corrosion resistance and favorable mechanical properties well suited for a variety of biomaterial applications. The native oxide surface on titanium alloys has been shown to be less than ideal and surface modification is often needed. Previously, an optimized anodization process was shown to form a porous phosphorus‐enhanced anatase oxide layer on commercially pure Ti grade 4. The anodized layer was shown to improve osseointegration and to reduce bacteria attachment when photocatalytically activated with UVA preillumination. The primary objective of the present study was to create a similar phosphorus‐enhanced anatase oxide layer on series of titanium alloys including commercially pure Ti grade 4, Ti‐6Al‐7Nb, Ti‐6Al‐4V ELI, alpha + beta Ti‐15Mo, beta Ti‐15Mo, and Ti‐35Nb‐7Zr‐5Ta. Phosphorus‐enhanced anatase oxide layers were formed on each titanium substrate. Anatase formation was shown to generally increase with oxide thickness, except on substrate alloys containing niobium. Phosphorus uptake was shown to be dependent on the titanium alloy chemistry or microstructure. Anodized layers formed on beta‐structured titanium alloys revealed the lowest phosphorus uptake and the most nanosized surface porosity. A methylene blue degradation assay showed anodized layers on commercially pure Ti and both Ti‐15Mo alloys to exhibit the highest levels of photocatalytic activity. Given the range of mechanical properties available with the commercially pure Ti and Ti‐15Mo alloys, the results of this study indicate the benefits of phosphorus‐enhanced anatase oxide coatings may be applicable to a wide variety of biomaterial applications.

Are Nano TiO2 Inclusions Improving Biocompatibility of Photocurable Polydimethylsiloxane for Maxillofacial Prosthesis Manufacturing?

(1) Background: The development of a biocompatible material for direct additive manufacturing of maxillofacial extraoral prosthesis is still a challenging task. The aim of the present study was to obtain a photocurable PDMS, with nano TiO2 inclusions, for directly 3D printing of extraoral, maxillofacial prosthesis. The biocompatibility of the newly obtained nanocomposite was also investigated; (2) Methods: 2.5% (m/m) titania nanoparticles (TiO2) oxide anatase and a photoinitiator, benzophenone (BF) 4.5% were added to commercially available PDMS for maxillofacial soft prostheses manufacturing. The three different samples (PDMS, PDMS-BF and PDMS-BF-TiO2) were assessed by dielectric curing analysis (DEA) based on their viscosities and curing times. In vitro micronucleus test (MNvit) was performed for genotoxicity assessment and three concentrations of each compounds (2 mg/L, 4 mg/L and 8 mg/L) were tested in duplicate and compared to a control; (3) Results: The nanocomposite PDMS-BP-TiO2 was fully reticulated within a few minutes under UV radiation, according to the dielectric analysis. PDMS-BF-TiO2 nanocomposite showed the lowest degree of cyto- and genotoxicity; (4) Conclusions: In the limits of the present study, the proposed ex situ preparation of a PDMS-BP-TiO2 offers an easy, simple, and promising technique that could be successfully used for 3D printing medical applications.

In situ carbon felt anode modification via codeveloping Saccharomyces cerevisiae living-template titanium dioxide nanoclusters in a yeast-based microbial fuel cell

Titanium dioxide (TiO2) nanoclusters grown in situ by Saccharomyces cerevisiae as a living-template atop a seeded and polyethylenimine functionalized carbon felt are explored for the first time for the enhanced performance of the anode within a yeast-based microbial fuel cell (MFC). Widespread, extensive, and synergistic growth of both the yeast biofilm and TiO2 nanoclusters are observed on the hydrophilic surface of the functionalized carbon felt fibers. The entirely green and inexpensive process required only the use of a nanoparticle seed that also acts as the nanoparticle growth initiator: titanium(IV) oxide anatase. The structure and morphology of the TiO2 nanostructures are examined through optical measurements after full experimentation within a yeast-based MFC system. Due to the extensive evocation of the exopolysaccharides matrix of the yeast through the well-timed introduction of the nanoparticle growth initiator, the yeast biofilm is beneficially affected by the presence of the TiO2 nanoclusters, thus improving the yeast biofilm maturation and electrochemical behaviour. How the yeast biofilm reacts to the invasion of foreign metallic nanoparticles and how this is beneficial to MFC research are explored. The best power density of the MFC achieved through this method was 25.9 ± 6.2 W m−2, an astounding value that far exceeds similar modification techniques to the MFC anode.

First-Principles Study of Electronic and Magnetic Properties of Anatase and its Role in Anatase-Mxene Nanocomposite

The electronic and magnetic properties of Titanium and one of its oxide Anatase are calculated by using Tight Binding Linear Muffin-Tin Orbital Atomic Sphere Approximation (TB-LMTO-ASA) method under Density Functional Theory (DFT). The lattice parameter, band structure, Density of States (DOS) and charge density distributions of Ti and TiO2 (Anatase) required for electronic structure are calculated respectively. The orbital contribution is analyzed by fat band structure; the d- orbital on conduction band and, s and p orbitals on valance bands. Consequently, their magnetic properties are checked. From our study, we found that the magnetic moments of Ti and TiO2 are found to be 2.2 μB and 0 respectively. The total Density of States for spin up and down electron have smaller difference in Ti and symmetric in TiO2 indicates that Ti slightly paramagnetic and Anatase is non magnetic in nature. The charge density plots reveals the concentration of electrons at the site under study. Anatase can be deposited onto Mxene to form Mxene-Anatase nanocomposite which has several excellent applications in the field of biosensors, biocompatible materials, energy storage devices, topological insulators etc.

Early plant growth and bacterial community in rhizoplane of wheat and flax exposed to silver and titanium dioxide nanoparticles

Silver and titanium dioxide nanoparticles (AgNPs and TiO2NPs) are highly useful, but they are also a significant reason for concern as they exert toxicity. The goal of research was to assess the role of three kinds of NPs in concentrations of 100 mg L−1 on early growth plants (wheat, flax) and bacterial community in rhizoplane. Titanium (IV) oxide anatase (TiO2NPs1) and titanium (IV) oxide nanopowder (TiO2NPs2) are commercial products. A suspension of AgNPs was prepared via a procedure of reduction with tannic acid. The response of Monocot and Dicot growth form plants to the tested NPs was different. Germination and seedling growth of wheat treated with TiO2NPs1 was better. The response of flax to NPs was noted as an increase of chlorophyll content. The bacterial community in wheat rhizoplane was not significantly modified, but there was a declining trend. In turn, a difference in the surface charge of NPs had an influence on the total bacterial community in Dicot rhizoplane. Positively charged TiO2NPs2 significantly decreased the quantity of total bacteria in contrast to negatively charged AgNPs and TiO2NPs1 which increased it. A qualitative analysis did not confirm the influence of the surface charge of NPs on an increase/decrease in the quantity of Pseudomonas and Bacillus bacteria, but did show that there was no toxicity of the tested NPs to the plant growth-promoting bacteria community. The rhizoplane microbiome was dependent on the species of plant, and the bacteria found in the communities are sensitive to NPs to a varying degree.

Functionalization of Ti99.2 substrates surface by hybrid treatment investigated with spectroscopic methods

The article presents spectroscopic investigation of Ti 99.2 based functional substrates formed by hybrid oxidation process. Surface treatments were performed by combining methods of fluidized bed atmospheric diffusion treatment (FADT) with physical vapor deposition (PVD) – magnetron sputtering and laser surface texturing (LST) treatments. The processes were implemented to form a titanium diffusive layer saturated with oxygen in the substrate and a tight homogeneous oxide coating on Ti surface deposited with magnetron sputtering or laser texturing technique. The hybrid treatment was realized in Al2O3 fluidized bed reactor with air atmosphere, at 640 °C for 8 h and 12 h. At the same time, magnetron sputtering with the use of TiO2 target at a pressure of 3 × 102 mbar and laser surface texturing treatment with Nd:YAG λ = 1064 nm was performed. In order to investigate the effects of hybrid oxidation, microscopic (AFM, CLSM, SEM/SEM-EDX), spectroscopic (RS) and X-ray investigations (GID-XRD) were performed. Applied hybrid technique made possible to combine the effects of the generated layers and to reduce the stresses in the area of the PVD coating/oxidized Ti substrate interface. Furthermore, Raman spectroscopy results obtained at oxide layers manufactured with different variants of oxidation allowed detailed analysis of the created oxides. The coatings have shown structure with a Tiα(O) diffusion zone, a TiO2 rutile and anatase oxide zone deposited and textured on the substrate. Phase composition and morphology of these oxides is essential for the osseointegration process i.e. intensity of hydroxyapatite growing on the implant surface. Performed processes influenced the surface roughness parameter and cause the increase of substrate functional properties, which are important for biomedical applications.

Duplex Titanium Oxide Layers for Biomedical Applications

Abstract This article presented the results of Ti Grade 2 oxidation with the duplex/hybrid method, which combined fluidized bed atmospheric diffusive treatment (FADT) and treatment with plasma methods (PVD). The process was realized to form a titanium diffusive layer saturated with oxygen in the diffusion process and to produce a tight homogeneous oxide coating on Ti substrate, deposited with the magnetron spraying technique. The techniques applied made it possible to combine the synergetic effects of the layers generated and to reduce the stresses in the area of the PVD coating/oxidized Ti substrate interface. In addition, the processes influenced the decrease in the surface roughness parameter and the increase in substrate bio-compatibility, which resulted in easier hydroxyapatite clusters deposition. The diffusion process was realized in Al2O3 fluidized bed reactor, at 913 K for 8 h with air atmosphere, while the deposition of the oxide coatings was realized with magnetron sputtering, with the use of TiO2 target at a pressure of 3 × 10−2mbars. In order to assess the effects of Ti hybrid oxidation, microscopic (AFM, SEM, TEM-EFTEM), spectroscopic (GDOS), and X-ray tests (XRD, sin2Ψ) were performed. The coatings formed had structure, with a Tiα(O) diffusion zone and a TiO2 rutile and anatase oxide zone deposited on the substrate. It was concluded that hybrid method of duplex coatings formation (FADT + PVD) leads to reducing oxide layer defects after fluidized bed heat treatment and to generating a tight homogeneous layer with a favorable state of stress, which results in improving the bio-compatibility of the generated substrate, important from the biomedical applications point of view.

Effect of anodization and alkali-heat treatment on the bioactivity of titanium implant material (an in vitro study).

Objective:This study was aimed to assess the effect of anodized and alkali-heat surface treatment on the bioactivity of titanium alloy (Ti-6Al-4V) after immersion in Hank's solution for 7 days.Materials and Methods:Fifteen titanium alloy samples were used in this study. The samples were divided into three groups (five for each), five samples were anodized in 1M H3PO4 at constant voltage value of 20 v and another five samples were alkali-treated in 5 M NaOH solution for 25 min at temperature 60°C followed by heat treatment at 600°C for 1 h. All samples were then immersed in Hank's solution for 7 days to assess the effect of surface modifications on the bioactivity of titanium alloy. The different treated surfaces and control one were characterized by X-ray diffraction, atomic force microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transformation infra-red spectroscopy. Statistical analysis was performed with PASW Statistics 18.0® (Predictive Analytics Software).Results:Anodization of Ti-alloy samples (Group B) led to the formation of bioactive titanium oxide anatase phase and PO43− group on the surface. The alkali-heat treatment of titanium alloy samples (Group C) leads to the formation of bioactive titania hydrogel and supplied sodium ions. The reaction between the Ti sample and NaOH alkaline solution resulted in the formation of a layer of amorphous sodium titania on the Ti surface, and this layer can induce apatite deposition.Conclusions:The surface roughness and surface chemistry had an excellent ability to induce bioactivity of titanium alloy. The anodization in H3PO4 produced anatase titanium oxide on the surface with phosphate originated from electrolytes changed the surface topography and allowed formation of calcium-phosphate.

Nanomaterial induction of oxidative stress in lung epithelial cells and macrophages

Oxidative stress in the lung epithelial A549 cells and macrophages J774A.1 due to contact with commercially important nanomaterials [i.e., nano-silver (nAg), nano-alumina (nAl2O3), single-wall carbon nanotubes (CNT), and nano-titanium oxide anatase (nTiO2)] was evaluated. Nanomaterial-induced intracellular oxidative stress was analyzed by both H2DCFDA fluorescein probe and GSH depletion, extracellular oxidative stress was assessed by H2HFF fluorescein probes, and the secretion of chemokine IL-8 by A549 cells due to elevation of cellular oxidative stress was also monitored, in order to provide a comprehensive in vitro study on nanomaterial-induced oxidative stress in lung. In addition, results from this study were also compared with an acellular “ferric reducing ability of serum” (FRAS) assay and a prokaryotic cell-based assay in evaluating oxidative damage caused by the same set of nanomaterials, for comparison purposes. In general, it was found that nanomaterial-induced oxidative stress is highly cell-type dependent. In A549 lung epithelial cells, nAg appeared to induce highest level of oxidative stress and cell death followed by CNT, nTiO2, and nAl2O3. Different biological oxidative damage (BOD) assays’ (i.e., H2DCFA, GSH, and IL-8 release) results generally agreed with each other, and the same trends of nanomaterial-induced BOD were also observed in acellular FRAS and prokaryotic E. coli K12-based assay. In macrophage J774A.1 cells, nAl2O3 and nTiO2 appeared to induce highest levels of oxidative stress. These results suggest that epithelial and macrophage cell models may provide complimentary information when conducting cell-based assays to evaluate nanomaterial-induced oxidative damage in lung.

Ni-doped TiO2 nanotubes for wide-range hydrogen sensing

Doping of titania nanotubes is one of the efficient way to obtain improved physical and chemical properties. Through electrochemical anodization and annealing treatment, Ni-doped TiO2 nanotube arrays were fabricated and their hydrogen sensing performance was investigated. The nanotube sensor demonstrated a good sensitivity for wide-range detection of both dilute and high-concentration hydrogen atmospheres ranging from 50 ppm to 2% H2. A temperature-dependent sensing from 25°C to 200°C was also found. Based on the experimental measurements and first-principles calculations, the electronic structure and hydrogen sensing properties of the Ni-doped TiO2 with an anatase structure were also investigated. It reveals that Ni substitution of the Ti sites could induce significant inversion of the conductivity type and effective reduction of the bandgap of anatase oxide. The calculations also reveal that the resistance change for Ni-doped anatase TiO2 with/without hydrogen absorption was closely related to the bandgap especially the Ni-induced impurity level.

Enhanced HER and ORR behavior on photodeposited Pt nanoparticles onto oxide–carbon composite

The photodeposition process under ultraviolet domain for platinum nanoparticles was explored. The concomitant presence of different mechanisms during the photodeposition of Pt nanoparticles onto TiO2 in the presence of water and alcohol is evidenced. According to the process, one can devise various complex mechanisms. The presence of nanoparticulated oxide anatase phase enhances the photodeposition process of metal nanoparticles via the so-called heterogeneous photocatalysis. A description and the effect of mixing of various chemicals in the reactor reveal interesting information, which allows controlling the size of nanoparticles by the photodeposition process. This study also paves the way to decrease the amount of precious metals used in material composition used as catalysts towards hydrogen evolution reaction and oxygen reduction reaction for fuel cell technologies.

Electrodeposition, Characterization, and Corrosion Stability of Nanostructured Anodic Oxides on New Ti‐15Zr‐5Nb Alloy Surface

A new Ti‐15Zr‐5Nb alloy with suitable microstructure and mechanical properties was processed by galvanostatic anodization in 0.3 M H3PO4 solution and a continuous nanostructured layer of protective TiO2 oxide was electrodeposited. The obtained anatase oxide layer has a nanotubes‐like porosity (SEM observations) and contains significant amount of phosphorus in phosphotitanate compound embedded in the oxide lattice (Raman, FT‐IR, SEM, and EDX analysis). This layer composition can stimulate the formation of the bone and its porosity can offer a good scaffold for bone cell adhesion. The electrochemical behaviour, corrosion stability, and variations of the open circuit potentials, Eoc, and corresponding open circuit potential gradients, ΔEoc, for 1500 soaking hours in Ringer solutions of 3.21, 7.58, and 8.91 pH values were studied. The anodized layer was more resistant, stable (from EIS spectra), and was formed from an inner barrier insulating layer that assures the very good alloy corrosion resistance and an outer porous layer that provides the good conditions for cell development. The nanostructured alloy has higher corrosion stability, namely, a more reduced quantity of ions released and a lower toxicity than that of the bare one. The monitoring of Eoc and ΔEoc showed the enhancement and stabilizing of the long‐term passive state of the anodized alloy and, respectively, no possibility at galvanic corrosion.

Modeling with Hybrid Density Functional Theory the Electronic Band Alignment at the Zinc Oxide–Anatase Interface

The band alignment at semiconductor interfaces can be theoretically computed using periodic slab models together with hybrid functional density functional theory methods in which Hartree–Fock exchange mixing coefficients are properly chosen (as justified by their relationship with the dielectric constant), and the calculated electrostatic potential inside each slab is used as reference for the band-edge energies. This principle is applied here to the interface between wurtzite-type ZnO and anatase-type TiO2, two oxides with nearly identical band gap widths. According to the results, in a composite of both materials the conduction and valence bands of ZnO will lie ca. 0.3 eV lower in energy than those of anatase, influencing the way in which photogenerated electrons and holes will be routed in photocatalytic or photovoltaic systems which include interfaces between these two oxides. The performance improvement observed in dye-sensitized solar cells based on a nanostructured ZnO electrode when the surface of the latter is covered by a thin TiO2 layer is thus justified. The system may serve as an example for the estimation of the band alignment in other semiconductor junctions of interest in different kinds of devices.

H2 production by γ and He ions water radiolysis, effect of presence TiO2 nanoparticles

The effect of TiO2 particles on the yield of H2 formation under water radiolysis is measured. Irradiations were performed using a 60Co γ−ray source as well as with He ions particles (4He2+) generated by a cyclotron with an external beam energy of 6 MeV. The resulting hydrogen as a stable product of radiolysis was measured by mass spectrometry. G(H2) obtained for water radiolysis by He ions−irradiation in aerated and argon water are found to be 1.91 × 10−7 and 1.35 × 10−7 mol J−1, respectively. In the presence of titanium oxide anatase−type dispersed in water, under He ions−irradiation, G(H2) is found to increase slightly from 1.04 × 10−7 to 1.35 × 10−7 mol J−1 by increasing the specific surface from 8 to 253 m2/g, respectively. Under γ-irradiation, G(H2) is found to be 0.41 × 10−7 mol J−1 close to primary yield of hydrogen in presence of OH. Radical scavenger. In addition, radiolysis of water adsorbed in the titanium oxide with low water content, which corresponds to a few layers of water sorbed onto the solid surface gives a huge values of the G(H2). For the same amount of water, with using the dose absorbed by TiO2 particles, for He ions-irradiation, G(H2) increases from 14.5 × 10−7 to 35 × 10−7 mol J-1 by increasing the surface area of TiO2 nanoparticles from 4 to 52 m2/g, respectively. For γ−irradiation G(H2) is found to be 5.25 × 10−7 mol J-1 for the sample with 8 m2/g specific surface area.

Elaboration and characterization of nanocrystalline TiO2 thin films prepared by sol–gel dip-coating

Nanocrystalline TiO2 thin films were deposited on a ITO coated glass substrate by sol–gel dip coating technique, the layers undergo a heat treatment at temperatures varying from 300 to 450°C. The structural, morphological and optical characterizations of the as deposited and annealed films were carried out using X-ray diffraction (XRD), Raman spectroscopy, Atomic Force Microscopy (AFM), visible, (Fourier-Transform) infrared and ultraviolet spectroscopy, Fluorescence and spectroscopic ellipsometry. The results indicate that an anatase phase structure TiO2 thin film with nanocrystallite size of about 15nm can be obtained at the heat treatment temperature of 350°C or above, that is to say, at the heat treatment temperature below 300°C, the thin films grow in amorphous phase; while the heat treatment temperature is increased up to 400°C or above, the thin film develops a crystalline phase corresponding to the titanium oxide anatase phase. We have accurately determined the layer thickness, refractive index and extinction coefficient of the TiO2 thin films by the ellipsometric analysis. The optical gap decreases from 3.9 to 3.5eV when the annealing temperature increases. Photocatalytic activity of the TiO2 films was studied by monitoring the degradation of aqueous methylene blue under UV light irradiation and was observed that films annealed above 350°C had good photocatalytic activity which is explained as due to the structural and morphological properties of the films.

Thin film TiO 2 electrodes derived by sol–gel process for photovoltaic applications

Nanocrystalline anatase TiO 2 thin films are prepared by a single spin-coating process from the sols with different ethanol content. The influence of the ethanol content and the heat treatment temperature on the structural and optical properties of the thin films is characterized by X-ray diffraction, atomic electron microscopy, and UV–vis spectroscopy. The results indicate that an anatase phase structure TiO 2 thin film with nanocrystallite size of about 20 nm and high transmittance can be obtained at the heat treatment temperature of 400 °C or above, that is to say, at the heat treatment temperature below 300 °C, the thin films grow in amorphous phase with a smooth surface; while the heat treatment temperature is increased up to 400 °C or above, the thin film develops a crystalline phase corresponding to the titanium oxide anatase phase.

Preparation and Characterization of Anodized Titanium Surfaces and Their Effect on Osteoblast Responses

In this study, titanium (Ti) surface was modified by anodizing with a mixture of beta-glycerophosphate sodium and calcium (Ca) acetate, and the anodized surfaces were characterized by scanning electron microscopy, X-ray diffraction, and electron probe microanalysis. In vitro osteoblast response to anodized oxide was also evaluated. The anodic oxide produced was observed to have interconnected pores (0.5-2 microm in diameter) and intermediate roughness (0.60-1.00 microm). In addition, anodic oxide was observed to have amorphous and anatase oxide. Calcium and phosphorus ions were deposited on the Ti oxide during anodization. Osteoblast differentiation, as indicated by alkaline phosphatase production, was enhanced on anodized surfaces. It was thus concluded from this study that Ca phosphate can be deposited on Ti surfaces by anodization. It was also concluded that the phenotypic expression of osteoblast was enhanced by the presence of Ca phosphate and higher roughness on anodized Ti surfaces.

Effect of Heat-Treated Titanium Surfaces on Protein Adsorption and Osteoblast Precursor Cell Initial Attachment

The clinical success of dental implants is governed in part by surface properties of implants and their interactions with the surrounding tissues. The objective of this study was to investigate the effect of heat-treated titanium surfaces on protein adsorption and osteoblast precursor cell attachment in vitro. Passivated titanium samples used in this study were either non heat treated or heat treated at 750 degrees C for 90 minutes. It was observed that the contact angle on heat-treated titanium surfaces was statistically lower compared with the non-heat-treated titanium surfaces. The non-heat-treated titanium surface was also observed to be amorphous oxide, whereas heat treatment of titanium resulted in the conversion of amorphous oxide to crystalline anatase oxide. No significant difference in albumin and fibronectin adsorption was observed between the heat-treated and non-heat-treated titanium surfaces. In addition, no significant difference in initial cell attachment was observed between the two groups. It was concluded that heat treatment of titanium resulted in significantly more hydrophilic surfaces compared to non-heat-treated titanium surfaces. However, differences in oxide crystallinity and wettability were not observed to affect protein adsorption and initial osteoblast precursor cell attachment.