Titania Nanotube Arrays Research Articles

RNA-seq reveals correlations between cytoskeleton-related genes and the osteogenic activity of mesenchymal stem cells on strontium loaded titania nanotube arrays

Strontium loaded titania nanotube arrays (NTSr), as well as titania nanotube arrays (NT), have been regarded as effective coatings to promote bone regeneration on titanium implants, but an understanding of the full extent of early processes affected by such surface modifications is absent. To address this limitation, we performed RNA sequencing (RNA-seq) of Sprague-Dawley rat bone marrow mesenchymal stem cells (rBMMSCs) cultured on unmodified titanium sheets (Con), NT and NTSr specimens. By pairwise comparisons we found that NT and NTSr shared a majority of differentially expressed genes. The Gene Ontology (GO) analysis revealed that NT and NTSr up-regulated a bunch of genes that are annotated to the cytoskeleton. The results were supported by immunofluorescent, transmission electron microscopy (TEM) and western blotting assays. By inhibiting the cytoskeleton through pharmacological agents, the activities of alkaline phosphatase (ALP) on NT and NTSr were also suppressed. Informed by these results, we concluded that NT and NTSr specimens reorganized the cytoskeleton of cultured cells that may play a crucial role in osteogenic lineage commitment.

Fabrication of titanium dioxide nanotubes by difference the anodization voltage and time

In this paper, Titanium dioxide nanotube arrays (TNAs) were obtained by electrochemical anodization in the electrolyte containing 0.3 wt% solution of ammonium fluoride in 90 ml of ethylene glycol and 10 ml of deionized water. Following this the different conditions of voltage (5–50 V) and time (30 min − 2 h) at room temperature. The morphology, composition, and crystalline phases of the TNAs were examined by Field Emission Electron Microscope (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction technique (XRD), respectively. The results of the experiment show that anodizing time and anodizing potential affected the formation of TNAs. When anodizing potential increased anodizing time decreased but when anodizing potential decreased anodizing time increased. Moreover, the formation of titanium dioxide starts becoming tubes at 10 V. Also, the diameter of the TNAs were about 10–100 nm.

Фазовый переход первого рода в нанотубулярном диоксиде титана

Titanium dioxide (TiO2) nanotubes array with the length of 16 μm and the outer diameter of 100 nm were synthesized by anodic oxidation of titanium foil in an electrolyte solution containing a fluorine-containing solution of ethylene glycol. The selected synthesis conditions make it possible to separate the nanotubular array from the titanium foil and study it as a homogeneous functional material. The performed scanning electron microscopy study and Brunauer–Emmett–Teller analysis allowed to get data on the morphology of the samples. X-ray diffraction, thermogravimetric, and differential scanning calorimetry analysis made it possible to determine the temperature of the phase transition of the amorphous state into crystalline anatase (sp.gr. I4/amd). Observed phase transition of first order takes place at temperature about 350 °С.

Recovery and separation of uranium in a microbial fuel cell using a titanium dioxide nanotube array cathode

Microbial fuel cell with titanium dioxide nanotube array cathode was first demonstrated as a promising approach for uranium recovery and separation from groundwater.

Targeting Early Healing Phase with Titania Nanotube Arrays on Tunable Diameters to Accelerate Bone Regeneration and Osseointegration

Blood coagulation and inflammation are the earliest biological responses to implant surfaces. Implant nano-surfaces can significantly impact the osseointegration through the influence on the early phase of bone regeneration. However, the interplay between blood clot property and inflammatory reaction on nanosurfaces is rarely understood. Herein, titania nanotube arrays (TNAs) with different diameters are fabricated on titanium. In vitro evaluation with the whole blood indicates that TNA with a diameter of 15 nm (TNA 15) enables noteworthy platelet activation resulting in distinct clot features compared with that of pure Ti and TNA with a diameter of 120 nm (TNA 120). Further co-culture with macrophages on the clot or in the clot-conditioned medium shows that the clot on TNA 15 downregulates the inflammation and manipulates a favorable osteoimmunomodulatory environment for osteogenesis. In vivo studies further demonstrate that TNA 15 could downregulate the inflammation-related genes while upregulating growth metabolism-related genes in an early healing hematoma. Additionally, TNA 15 promotes de novo bone formation with improved extending of osteocyte dendrites, demonstrating the desired osseointegration. These findings indicate that surface nano-dimensions can significantly influence clot formation and appropriate clot features can manipulate a favorable osteoimmunomodulatory environment for bone regeneration and osseointegration.

Characterization and mechanical properties of TiO2 nanotubes formed on titanium by anodic oxidation

The well-ordered titanium dioxide (TiO2) nanotube array surfaces were formed at different voltages such as 20 V, 40 V, 60 V, 80 V and 100 V for 1 h on cp-Ti by anodic oxidation (AO) technique. And then, to improve crystallinity of the surface, heat treatment was applied at 450 °C for 1 h to all surfaces without any morphological changing. The surface and cross sectional morphology, elemental structure, phase composition, functional groups, roughness and thickness, wettability and mechanical results were investigated by SEM, EDX, XRD, FT-IR, AFM, contact angle measurement device and nanoindentation tester, respectively. Mainly, anatase- and rutile-TiO2 phases were obtained at post-heat treatment whereas only, Ti phase was detected on AO surfaces at pre-heat treatment. All nanotube structures and the elements of Ti and O were uniformly distributed through the whole surface. The roughness and thickness of tube structures usually increased with increasing voltage values and measured. The roughness and thickness values were measured as 10.67–111.97 nm and 0.21–1.92 μm, respectively. TiO2 nanotube surfaces exhibited hydrophobic behaviors with respect to plain Ti surface. Furthermore, mechanical properties such as hardness and elastic modulus of the coating produced at minimum voltage were great compared to ones at higher voltage and plain Ti surface under a Berkovich indenter due to phase structure, homogeneity and density of nanotube structures.

Highly Ordered of Anatase Titanium Dioxide Nanotube Arrays at Different Calcination Temperatures via Electrochemical Anodization Method

Highly ordered titanium dioxide nanotube arrays (TNTAs) were fabricated via electrochemical anodization of Ti sheet in electrolyte containing aqueous and nonaqueous electrolyte. The formation of highly ordered TNTAs was varied by calcination temperatures (350, 450, 550oC) for 120 minutes to investigate the effect of calcination temperature on surface morphology, roughness, crystallinity and band gap energy. The field emission scanning electron microscopy revealed that the prepared TNTAs grow uniformly with average diameter in the range of 48.23 to 52.14 nm as the temperature increased from 350 to 550oC. The X-ray diffraction pattern showed the TNTAs exhibit anatase phase with prominent (101) peak recorded for the sample calcined at 450oC. The transformation from anatase to rutile phase appeared after calcination at 450oC. The band gap value (~3.24 eV) was obtained for all calcination temperature sample due to homogeneity of the TNTAs structures.

Effect of Electrolyte Composition on Structural and Photoelectrochemical Properties of Titanium Dioxide Nanotube Arrays Synthesized by Anodization Technique

The present work involves studying the effect of electrolyte composition [@1= 0.5 wt.% NH4F / 5% H2O / 5% Glycerol (GLY)/ 90% Ethylene Glycol (EG)] and [ @2= 0.5 wt. % NH4F / 5% H2O / 95% Ethylene Glycol (EG)] on the structural and photoelectrochemical properties of titania nanotubes arrays (TNTAs). TNTAs substrates were successfully carried out via anodization technique and were carried out in 40 V for one hour in different electrolytes (@1, and @2). The properties of physicochemical of TNTAs were distinguished via an X-ray Diffractometer (XRD), Field Emission Scanning Electron Microscope (FESEM), an Energy Dispersive X-ray (EDX), and UV–visible diffuse reflectance. The photoelectrochemical response of TNTAs was evaluated in 0.01M Na2S under the choppy light of a halogen lamp. TNTAs photoelectrode prepared at @1 electrolyte was not sufficient to increase the photocurrent response compared to TNTAs prepared at @2. The TNTAs photoelectrode prepared in the @2 electrolyte confirmed the highest photoconversion efficiency compared to the TNTAs photoelectrode prepared in the @1 electrolyte.

Nanofibrillated chitosan coated highly ordered titania nanotubes array/graphene nanocomposite with improved biological characters

Designing multifunctional surfaces is key to develop advanced materials for orthopedic applications. In this study, we design a double-layer coating, assembled onto the completely regular titania nanotubes (cRTNT) array. Benefiting from the biological and topological characteristics of chitosan nanofibers (CH) and reduced graphene oxide (RGO) through a unique assembly, the designed material features promoted osteoblast cell viability, prolonged antibiotic release profile, as well as inhibited bacterial biofilm formation. The synergistic effect of RGO and CH on the biological performance of the surface is investigatSed. The unique morphology of the nanofibers leads to the partial coverage of RGO-modified nanotubes, providing an opportunity to access the sublayer properties. Another merit of this coating lies in its morphological similarity to the extracellular matrix (ECM) to boost cellular performance. According to the results of this study, this platform holds promising advantages over the bare and bulk biopolymer-modified TNTs.

Growth of silver nanodendrites on titania nanotubes array for photoanode driven photoelectrocatalytic reduction of carbon dioxide

Photoanode based CO2 reduction has two major advantages- water oxidation provides required electron-hole pairs and photogenerated anode current compensates the negative cathodic potential required for CO2 reduction. Generally, silver dendrites in combination with copper based substrates have been reported as electrocathodes for electrochemical CO2 reduction. Whereas, in this work, silver nanodendrites decorated titania nanotubes array (Ag-TNT) was used as a photoanode and prepared via simple sodium citrate assisted electrodeposition. Silver dendrites have influenced in light absorption, charge separation efficiency. Ag-TNT employed in photoanode for photoelectrocatalytic reduction of CO2 into CO under the optimized condition with a photocurrent density of 0.29 mA cm−2 at 1.23 V (vs. RHE). This system yielded CO of 61 μmol cm2/h and the design paves the way to facilitate photoelectrocatalytic CO2 reduction through water oxidation.

Impedimetric Detection of Femtomolar Levels of Interleukin6, Interleukin 8, and Tumor Necrosis Factor Alpha Based on Thermally Modified Nanotubular Titanium Dioxide Arrays.

An inexpensive, easy to prepare, and label-free electrochemical impedance spectroscopy-based biosensor has been developed for the selective detection of human interleukin 6 (IL-6), interleukin 8 (CXCL8, IL-8), and tumor necrosis factor (TNFα)—potential inflammatory cancer biomarkers. We describe a, so far, newly developed and unexplored method to immobilize antibodies onto a titanium dioxide nanotube (TNT) array by physical adsorption. Immobilization of anti-IL-6, anti-IL-8, and anti-TNFα on TNT and the detection of human IL-6, IL-8, and TNFα were examined using electrochemical impedance spectroscopy (EIS). The impedimetric immunosensor demonstrates good selectivity and high sensitivity against human biomarker analytes and can detect IL-6, IL-8, and TNFα at concentrations as low as 5 pg/mL, equivalent to the standard concentration of these proteins in human blood. The calibration curves evidenced that elaborated biosensors are sensitive to three cytokines within 5 ÷ 2500 pg/mL in the 0.01 M phosphate-buffered saline solution (pH 7.4).

Molecularly imprinted photo-electrochemical sensor for hemoglobin detection based on titanium dioxide nanotube arrays loaded with CdS quantum dots

A novel molecularly imprinted photo-electrochemical sensor based on CdS/TiO2 nanocomposites was constructed for precisely detection of hemoglobin under visible light irradiation. CdS quantum dots were decorated on the surface of TiO2 nanorod arrays to form a heterojunction, which could enhance the charge-transfer efficiency for visible light and further increase the photo-generated current of the sensor. The molecularly imprinted polymer film assembled by dopamine monomer had achieved excellent performance for specifically binding with human hemoglobin. The hemoglobin bound on the sensor could catalyze the oxidation reaction of 4-chloro-1-naphthol by H2O2, generating insoluble product on the sensor surface and triggering an obviously decrease on photocurrent. The molecularly imprinted photo-electrochemical sensor exhibited excellent sensitivity, selectivity and stability for the detection of human hemoglobin. The sensor had a linear range from 0.01 to 100 ng mL−1 with a detection limit of 0.53 pg/mL (S/N = 3). Furthermore, the sensor was successfully applied on the analysis of human hemoglobin in the urine samples.

Formation of the hollow nanopillar arrays through the laser-induced transformation of TiO2 nanotubes

In the following article, we present a simple, two-step method of creating spaced, hollow nanopillars, from the titania nanotube arrays via pulsed laser-treatment. Due to the high ordering of the structure, the prepared material exhibits photonic properties, which has been shown to increase the overall photoefficiency. The optical and morphological changes in the titania nanotubes after pulsed laser-treatment with 532, 355, and 266 nm wavelengths in the 10–50 mJ/cm2 fluence range are studied. The investigation reveals, that by using appropriate wavelength and energy, the number of surface defects, geometrical features, or both can be tailored.

Green Synthesized Palladium Coated Titanium Nanotube Arrays for Simultaneous Azo-Dye Degradation and Hydrogen Production

In this study, electrodes of titanium dioxide nanotube arrays (TNAs) were successfully synthesized by applying the anodic oxidation etching method, as well as the use of green synthetic technology to add reducing agents of tea or coffee to reduce metal palladium from palladium chloride. Synthesis of palladium modified TNAs (Pd/TNAs) was conducted by the microwave hydrothermal method after the metal palladium was reduced. In order to identify the surface structure, light absorption and elemental composition, TNAs and Pd/TNAs were characterized by X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Furthermore, to test the photocurrent density, electron resistance, and hydroxyl radicals by I-t plot, electrochemistry impedance spectroscopy (EIS), and electron paramagnetic resonance (EPR) were investigated. The photocurrent (4.0 mA/cm2) of Pd/TNAs-C (using coffee as the reducing agent) at +1.0 V (vs. Ag/AgCl) was higher than that of the pure TNAs (1.5 mA/cm2), illustrating that Pd/TNAs-C can effectively separate photogenerated electrons and holes. Pd/TNAs is a favorable material as a photoanode for the photoelectrochemical (PEC) removal of organic pollutants in wastewater.

Growing vertical aligned mesoporous silica thin film on nanoporous substrate for enhanced degradation, drug delivery and bioactivity

Mesoporous silica thin film has been widely used in various fields, particularly the medical implant coating for drug delivery. However, some drawbacks remain with the films produced by traditional method (evaporation-induced self-assembly, EISA), such as the poor permeability caused by their horizontal aligned mesochannels. In this study, the vertical aligned mesoporous silica thin film (VMSTF) is uniformly grown alongside the walls of titania nanotubes array via a biphase stratification growth method, resulting in a hierarchical two-layered nanotubular structure. Due to the exposure of opened mesopores, VMSTF exhibits more appealing performances, including rapid degradation, efficient small-molecular drug (dexamethasone) loading and release, enhanced early adhesion and osteogenic differentiation of MC3T3-E1 cells. This is the first time successfully depositing VMSTF on nanoporous substrate and our findings suggest that the VMSTF may be a promising candidate for bone implant surface coating to obtain bioactive performances.

Synthesis of Ni- and N-Doped Titania Nanotube Arrays for Photocatalytic Hydrogen Production from Glycerol–Water Solutions

Synthesis of Ni- and N-doped Titania Nanotube Arrays (Ni-N-TiNTAs) was conducted to produce photocatalysts for hydrogen production from a glycerol–water mixture. Ni-N-TiNTAs were synthesized in two steps, namely anodization and chemical reduction. Ti foil was anodized at 50 V for two h in an electrolyte solution containing 0.2% urea as a source of N atoms. Ni doping (at various content of 5%, 10%, 15%, and 20% wt) was performed by one-hour chemical reduction with sodium borohydride as a reducing agent. The photocatalyst was annealed at different temperatures, i.e., 500 °C, 550 °C, and 600 °C under 60 mL/min N2 gas for two h. On the basis of X-ray Diffraction (XRD) patterns, Ni-N-TiNTAs are mostly of anatase crystallite phase when annealed at 500 °C and 550 °C, while that of rutile was observable when calcination was done at 600 °C. The morphology of the photocatalysts was scrutinized by means of Field Emission Scanning Electron Microscopy (FESEM) imaging, which reveals nanotubular structures, with elemental composition measured by Energy Dispersive X-ray (EDX). The bandgap of the photocatalysts was analyzed using Ultraviolet Diffuse Reflectance Spectroscopy (UV DRS), which showed a lower value for the case of Ni-N-TiNTAs as compared to those of TiNTAs and N-TiNTAs. Photocatalytic tests showed that the highest amount of hydrogen produced (ca. 30973 μmol/m2) was obtained in the case of Ni-N-TiNTAs with a Ni content of 10wt%.

The preparation of black titanium oxide nanoarray via coking fluorinated wastewater and application on coking wastewater treatment

Coking wastewater is extremely toxic with poor biodegradability owing to the presence of refractory organics. Black titanium oxide nanotube array (BTN), not only photocatalyst but also electrocatalyst, is with definite potentiality in organic wastewater treatment. Here, we firstly developed an electrochemical method, using fluorinated coking wastewater as electrolyte rather than traditional fluorinated ethylene glycol, to prepare titanium oxide nanoarray economically. Unexpectedly, suspended pollutants and ammonia nitrogen in coking wastewater were removed in BTN preparation. Moreover, the as-prepared BTN could be further employed as photocatalyst or electrocatalyst to degrade dissolved organic matter in coking wastewater. As an electrocatalyst, BTN possessed the comparable •OH production activity about 9.9 × 10−15 M S−1 to boron-doped diamond, high oxygen evolution potential around 2.75 V, and high selectivity of chlorine production. Moreover, the biodegradability of treated coking wastewater could be effectively improved by using BTN as electrocatalyst in electrochemical oxidation, and the BOD/COD was from 0.19 to above 0.3 in 4 h at current density of 2 mA cm−2. The energy consumption was about 63–68 kWh kgCOD−1, lower than that of various reported electrodes. This study provided an economical and environmentally friendly method to prepare BTN, which was with positive application prospect in the field of coking wastewater treatment.

Titania nanotube array decorated in polymer matrix as a free-standing anode material for lithium-ion batteries

Polypyrrole (Ppy) is coated on titanium dioxide nanotubes arrays (TNAs) by using electrochemical method. Both TNAs and TNAs/Ppy are used as free-standing anode material in lithium-ion batteries (LiBs). The as-grown TNAs anode-based LiB shows a specific capacity ∼ 207 μA h cm−2, which is enhanced ∼ 330 μA h cm−2 significantly with the introduction of Ppy. A stable columbic efficiency ∼ 99.9 % and an excellent rate performance is observed in TNAs/Ppy based LiBs.

Gentamicin-Loaded TiO2 Nanotubes as Improved Antimicrobial Surfaces for Orthopedic Implants

Titanium oxide nanotube arrays are extremely promising materials for localized drug delivery in orthopaedic implants because of their excellent properties and facile preparation. TiO2 nanotubes act as an effective drug reservoir for localized drug delivery and promote faster tissue regeneration, effective osseointegration while, at the same time, preventing bacterial adhesion and implant infection. Here, highly ordered TiO2 nanotubes (NTs) were synthesized by electrochemical anodization of Ti sheets and the process voltage was varied to obtain surfaces with different NTs diameters. The effect of NTs dimension on cell and bacterial adhesion and on gentamicin loading and release was assessed. Anodization was confirmed an easy and effective method to prepare highly ordered, open top nanotubes with predictable diameter as a function of imposed voltage. A lower number of bacteria Staphylococcus Aureus adhesion was found to be reduced on NTs surfaces and on smaller nanotubes in particular. When gentamicin was loaded, protracted release and antibacterial action was observed and bacteria were not observed, either in planktonic or adhered. Moreover, higher cell proliferation and a more favourable cell morphology were observed on smaller nanotubes, to further support the indication toward a reduction in NTs diameter for the preparation of effective implant surfaces.

Well‐dispersed Au nanoparticles prepared via magnetron sputtering on TiO2 nanotubes with unprecedentedly high activity for water splitting

AbstractWe report on the fine tuning of sputtered gold nanoparticles (Au NPs) with optimized diameters (7–25 nm) and distribution on the high surface area titania nanotube arrays (TNTs). The uniform coverage of Au NPs both outside and inside the nanotube arrays was possible by adjusting the sputtering current, as confirmed via scanning electron microscopy imaging and X‐ray diffraction analysis. Decorating the TNTs with Au NPs extended their optical activity to the visible region of the light spectrum. This red shift was attributed to the localized surface plasmon resonance (LSPR) of Au NPs as verified computationally and experimentally. The Au–TiO2 composites demonstrated 86% increase in the photocurrent compared to the bare TNTs upon their use as photoanodes for water splitting. The photoactivity was found to depend on the size of the sputtered Au NPs. The photocurrent transient measurements under light on/off conditions revealed the photostability of the Au–TiO2 nanocomposites. The Mott–Schottky analysis showed a negative shift in the flat band position of the Au–TiO2 electrodes with increased donor density compared to the bare TNTs. Moreover, the Au–TiO2 showed lower space charge capacitance and longer life time of charge carriers.