Titanium Nanostructures Research Articles

Studies, characterizations and evaluation of the antibacterial activity of Silver Titanate Nanotubes

Titanium nanostructures have been widely studied due to their potential for various applications. One of its most promising applications is in the antibacterial activity, in particular, of Silver Titanate Nanoubes (Ag-TiNT). The determining factors for the high efficiency process against bacteria are related to the surface area of the material and the main metal that composes it. Microbial infections continue to be one of the most serious complications in different areas, particularly in the hospital environment. This work was investigated as bactericidal properties of Silver Titanate nanotubes against Gram-negative bacteria of Escherichia coli and Pseudomonas aeruginosa and Gram-positive bacteria of Staphylococcus aureus, in systems containing only the Ag-TiNT for the antibiotic compounds. In addition, the study of the main, vibrational and morphological characteristics of Ag-TiNT was carried out. As a result, as microdilution plates accompanying only the positive anti-bacterial dish, while in the microdilution plates containing Ag-TiNT with antibiotics, divergent results. Abstract: Ag-TiNT morphology structures, electron microscopy (SEM, TEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and dispersion spectroscopy were detected of X-ray energy (EDS).

Investigating the influence of pore-widening time control in electrochemical anodization for the formation of hybrid titanium nanostructures with enhanced superhydrophobicity for improved corrosion resistance efficiency

Titanium (Ti) alloys possess remarkable strength, high-temperature stability, and processability, making them indispensable in biomaterials, aircraft engines, fuselage manufacturing, and ship propulsion shafts. However, when exposed to potential differences or minor defects in contact with other alloys, the thin natural oxide film on their surface is vulnerable to damage, leading to accelerated corrosion or diminished stability. This study investigated the morphology of the final oxide film formed with varying pore-widening (PW) process time (10–60 min with 10-minute intervals) after the anodization of Ti-Grade 4 material. The oxide films formed from the anodization and the PW process for 10 to 40 min exhibited a porous structure, while a hybrid pillar and pore structure were observed after a PW process of 50 min. As the PW time increases, the pore diameter expands, forming hybrid pillar and pore nanostructures, and superhydrophilicity is observed. After FDTS (1H, 1H, 2H, 2H-Perfluorooctyltrichlorosilane) coating, the phenomenon elucidates the transition from hydrophobicity to superhydrophobicity and the enhancement of water droplet mobility, with the lowest contact angle hysteresis measured at PW of 60 min and demonstrating improved corrosion resistance, achieving a corrosion inhibition efficiency of over 99% compared to the untreated titanium alloy surface. Notably, the structure encompassing pillar and pore features exhibits exceptional suitability for applications on material surfaces and interfacial phenomena, such as cell adhesion. Furthermore, surfaces characterized by excellent superhydrophobicity because of coating can find multifunctional applications encompassing anti-corrosion, anti-fouling, anti-icing, and self-cleaning capabilities.

Investigation of the antiadhesive properties of biomimetic titanium nanostructures in fluidic flow

Abstract Within this work, the bacterial adhesion on biomimetic titanium nanostructures is investigated in fluidic flow. The motile, gram-negative bacteria strain Escherichia coli was used for the experiments and was incubated on nanostructured titanium, polished titanium and on the wings of the dragonfly Neuorbasis kaupi. After incubation period different flow velocities have been applied and the reduction of adhered bacteria was determined via fluorescence microscopy. Results show that nanostructured titanium surfaces have the ability to reduce the bacterial contamination as it is for the dragon fly wings used in this study. This behavior can also be predicted by analyzing the bearing area of the nanotopography which describes the actual part of the topography which is in contact to the bacteria.

Dual-action silver functionalized nanostructured titanium against drug resistant bacterial and fungal species

HypothesisTitanium and its alloys are commonly used implant materials. Once inserted into the body, the interface of the biomaterials is the most likely site for the development of implant-associated infections. Imparting the titanium substrate with high-aspect-ratio nanostructures, which can be uniformly achieved using hydrothermal etching, enables a mechanical contact-killing (mechanoresponsive) mechanism of bacterial and fungal cells. Interaction between cells and the surface shows cellular inactivation via a physical mechanism meaning that careful engineering of the interface is needed to optimse the technology. This mechanism of action is only effective towards surface adsorbed microbes, thus any cells not directly in contact with the substrate will survive and limit the antimicrobial efficacy of the titanium nanostructures. Therefore, we propose that a dual-action mechanoresponsive and chemical–surface approach must be utilised to improve antimicrobial activity. The addition of antimicrobial silver nanoparticles will provide a secondary, chemical mechanism to escalate the microbial response in tandem with the physical puncture of the cells. ExperimentsHydrothermal etching is used as a facile method to impart variant nanostrucutres on the titanium substrate to increase the antimicrobial response. Increasing concentrations (0.25 M, 0.50 M, 1.0 M, 2.0 M) of sodium hydroxide etching solution were used to provide differing degrees of nanostructured morphology on the surface after 3 h of heating at 150 °C. This produced titanium nanospikes, nanoblades, and nanowires, respectively, as a function of etchant concentration. These substrates then provided an interface for the deposition of silver nanoparticles via a reduction pathway. Methicillin-resistant Staphylococcous aureus (MRSA) and Candida auris (C. auris) were used as model bacteria and fungi, respectively, to test the effectiveness of the nanostructured titanium with and without silver nanoparticles, and the bio-interactions at the interface. FindingsThe presence of nanostructure increased the bactericidal response of titanium against MRSA from ∼ 10 % on commercially pure titanium to a maximum of ∼ 60 % and increased the fungicidal response from ∼ 10 % to ∼ 70 % in C. auris. Introducing silver nanoparticles increased the microbiocidal response to ∼ 99 % towards both bacteria and fungi. Importantly, this study highlights that nanostructure alone is not sufficient to develop a highly antimicrobial titanium substrate. A dual-action, physical and chemical antimicrobial approach is better suited to produce highly effective antibacterial and antifungal surface technologies.

Ultra-Broadband, Polarization-Irrelevant Near-Perfect Absorber Based on Composite Structure.

This paper proposes a near-perfect absorption device based on a cross-shaped titanium nanostructure and a multilayered structure. The multilayered bottom structure consists of alternately SiO2 and Ti. The whole device is put on a TiN substrate. The coupling between cross-shaped titanium nanostructures, and that between the cross-shaped titanium nanostructure and bottom multilayer, can further enhance the absorption at some wavelength where most of the energy is reflected or passes through in the device with a single structure. According to the simulation results, the device presents a nearly perfect absorption in a wavelength range from 300 nm to 2000 nm. The average absorptance in the wavelength range from 500 nm to 1400 nm exceeds 96%. This paper also provides a new idea for realizing perfect absorption, which is extensively used in sensing, controllable thermal emission, solar energy harvesting solar thermo-photovoltaic devices, and optoelectronic metrology.

Behavior in the electric current curve by changing the anodizing area

In this work, we studied the change in the electric current and the length of the nanotubes depending on the area and the exposure time in the anodizing process. Over time the anodizing area was changed with a rate of 0.5 cm2 to 2.5 cm2 using a total anodizing time of 60 min, using a chemical solution (2ml /3 ml /0.30g ) and maintaining a constant anodizing voltage equal to 20 V. The behavior in the nanostructures was recorded by the evolution of the current density as a function of the anodizing time. The morphology of the nanostructures was analyzed by means of scanning electron microscopy (SEM). With the use of the Imagej program. The size, length and diameter of the titanium nanostructures are obtained. The sample that presented the best behavior was that of an anodizing area of ​​1.5 cm2 and an anodizing time of 36 min. This presents a surface where open nanotubes are observed in the upper part with a vertical length of 0.23 μm and a pattern thereof organized in a circular arrangement with a diameter of 0.035 μm. It was observed that increasing the area under these anodizing conditions decreased the length of the nanotubes. The mobility of the loads was always greater with the area of ​​exposure, which is observed in the increase of the current

Investigate the effect of the Nano zero valent iron and Nano titanium in the genetic materials of the living cell

Current knowledge of chemicals may not be sufficient to predict the toxicity of nanomaterial to humans, especially the synthesis of DNA inside the cell, so research in this area is necessary to predict these risks. In this study, the effect of the addition of zero-valent iron nanoparticle and Titanium dioxide nanoparticle on serum cellular material was studied. Iron nanostructures were prepared using sodium borohydride (NaBH 4 ) as a reducing agent. Titanium dioxide was purified and crystallized in the laboratory for the purpose of use in this research. Iron and titanium nanostructures were diagnosed with Fourier Transform Infrared Spectrophotometry (FTIR) and XRD (X-ray) spectra. The change in the DNA phenotype was monitored through the comet examination method, whereby a fluorescent microscope was used to monitor the change of DNA and to calculate the number of dead cells by comparing the sample and the reference in the experiment. Different concentrations of Nano scale iron and titanium dioxide were used (30 mg/ml, 5omg/ml and 100 mg/ml). It was found that the concentration of 100 mg/ml of the nanomaterial under investigation is the most effective for both Nano scale iron (Fe 0 ) and titanium dioxide (TiO 2 ). The result appears that the effect of titanium dioxide is more than the effect of Nano scale iron by increasing the number of dead cells via a percentage of 5.3% and 4%, respectively. Experience has shown that Nano zero valent iron has less toxic effect than titanium dioxide. In addition, the results showed a clear change in DNA morphology. The number of dead cells within the living cells understudy after the addition of nanoparticles with different concentrations, indicating the danger of nanomaterial on the genetic material of the human living cell.

Локальные и интегральные свойства квазиодномерного сверхпроводника в режиме квантовых флуктуаций параметра порядка

Utilization of superconducting materials for the new generation of nanoelectronic devices seems extremely tempting from the point of view of the absence of Joule heating. However, in small systems, the role of fluctuations can be very significant. In this work, the transport properties of thin superconducting titanium nanostructures were studied experimentally and theoretically. It has been shown that quantum fluctuations of the order parameter have a dif-ferent impact on integral and local characteristics of a quasi-one-dimensional superconductor. In sufficiently thin nanowires, a finite electrical resistance can be observed at the lowest tem-peratures, while the tunneling current-voltage characteristics exhibit only slightly broadened gap singularity and a finite Josephson current. The observation is of fundamental importance for understanding the phenomenon of mesoscopic superconductivity and should be taken into account when designing nanometer scale cryoelectronic devices.

Mathematical modeling and experimental analysis of the efficacy of photodynamic therapy in conjunction with photo thermal therapy and PEG-coated Au-doped TiO2 nanostructures to target MCF-7 cancerous cells.

Some nanoscale morphologies of titanium oxide nanostructures blend with gold nanoparticles and act as satellites and targeted weapon methodologies in biomedical applications. Simultaneously, titanium oxide can play an important role when combined with gold after blending with polyethylene glycol (PEG). Our experimental approach is novel with respect to the plasmonic role of metal nanoparticles as an efficient PDT drug. The current experimental strategy floats the comprehensive and facile way of experimental strategy on the critical influence that titanium with gold nanoparticles used as novel photosensitizing agents after significant biodistribution of proposed nanostructures toward targeted site. In addition, different morphologies of PEG-coated Au-doped titanium nanostructures were shown to provide various therapeutic effects due to a wide range of electromagnetic field development. This confirms a significantly amplified population of hot electron generation adjacent to the interface between Au and TiO2 nanostructures, leading to maximum cancerous cell injury in the MCF-7 cell line. The experimental results were confirmed by applying a least squares fit math model which verified our results with 99% goodness of fit. These results can pave the way for comprehensive rational designs for satisfactory response of performance phototherapeutic model mechanisms along with new horizons of photothermal therapy (HET) and photodynamic therapy (HET) operating under visible and near-infrared (NIR) light.

Carbon–titanium nanostructures: synthesis and characterization

C–Ti multilayer nanostructures were deposed by thermionic vacuum arc technology. The layers consisting of about 100 nm Carbon base layer and seven 40 nm alternatively Ti and C layers were deposed on Silicon substrates. On the other hand, in order to obtain C–Ti multilayer structures with variable thickness and different percentages in C and Ti of layers, a 20 nm thick C layer was first deposed on Si substrate and then seven Ti–C layers, each of these having thickness of up to 40 nm were deposed. To perform the successively layers with various thickness were changed the discharge parameters for C and Ti plasma sources to obtain the desirable thickness. By changing of substrate temperature between room temperature and 300 °C and on the other hand the bias voltage up to −700 V, different batches of samples were obtained for this study. To characterize properties of as prepared C–Ti multilayer structures were used electron microscopy techniques (TEM, STEM), Raman spectroscopy, RBS techniques and tribological measurements. To characterize the electrical conductive properties, the electrical surface resistance versus temperature have been measured, and then the electrical conductivity. Using the Wiedemann–Frantz law was calculated the thermal conductivity.

Surface-Modified Titanium Fibers as Durable Carbon-Free Platinum Catalyst Supports for Polymer Electrolyte Fuel Cells

Carbon-based electrodes in polymer electrolyte fuel cells (PEFCs) are prone to corrosion. Therefore, alternative “carbon-free” materials are required. Here, the use of a catalyst-coated porous metal support is proposed as a gas diffusion electrode. As a proof-of-concept, commercially available porous titanium sheets comprising sintered titanium fibers are chemically etched with NaOH, followed by heat treatment. This results in the formation of oxidized titanium nanostructures (such as nanosheets and nanotubes) at the surface. Subsequently, platinum decoration is performed via arc plasma deposition (APD). This porous composite structure is then attached to the membrane, and used as the gas diffusion electrode for PEFC membrane electrode assemblies (MEAs). This concept integrates the catalyst, catalyst support, gas diffusion layer, and current collector in a single structure, cutting down on the number of cell components and reducing total device thickness. The carbon-free nature of this integrated gas diffusion electrode is demonstrated to successfully avoid carbon corrosion during start-stop potential cycling over 60,000 potential cycles. However, further improvements in initial electrochemical activity are still required.

Unraveling the strength interaction in a TiO2-Graphene photocatalytic nanocomposite synthesized by the microwave hydrothermal method

Graphene oxide (GO) based composites were synthesized using a hydrothermal process, by these means, it was possible to tailor the loading of titanate nanotubes (TNTs) and TiO2 anatase particles in order to get insights into the photoactivity of the as-prepared photocatalyst. GO was prepared by the modified Hummers' method. The interactions stuck between titanium nanostructures and GO were studied by XRD, FESEM, FTIR, UV–vis and N2 physisorption along with computational studies using the DFT formalism on a graphene-TiO2 model. The photocatalytic performance was evaluated in the degradation of 4-clorophenol (4-CP) under UV light. The coexistence of anatase and titanate crystalline phases grown on the GO defects gave adsorptive and photocatalytic properties to the GO-based nanocomposites (TGO) and the favorable adsorption energy calculated by the DFT computational method showed that formyl acid surface groups on the tip area featured the main interaction of the TiO2-based photocatalyst. As a result, a photocatalyst with high surface area and functional sites was obtained, thus boosting the photoactivity and mass transfer properties to remove 4-CP from wastewater. Cycle voltammetry and electrochemical impedance measurements of the optimal TGO opened the possibility for using this material as a capacitor.

Sonochemical nanostructuring of titanium for regulation of human mesenchymal stem cells behavior for implant development

The influence of surface nanotopography of sonochemically generated mesoporous titania coatings (TMS) on the adhesion, proliferation, and osteogenic differentiation of human mesenchymal stem cells (hMSCs) have been investigated in vitro for the first time. It has been revealed that adhesion and proliferation of hMSCs is higher on disordered TMS surfaces compared to smooth polished titania surface after five days of incubation. Surprisingly, the sonochemically generated disordered nanotopography induces the differentiation of hMSCs into osteogenic direction in the absence of osteogenic medium in 14 days of incubation. Thus sonochemical nanostructuring of titanium based implants stimulates the regenerative process of bone tissue.

Nanostructuring of Titanium by Anodic Oxidation with Sulfuric and Hydrofluoric Acid

Abstract Within this work we demonstrate different Anodic Oxidation processes to achieve a broad variety of nanostructures on titanium and the titanium alloy Ti6Al4V for the use as medical implant surfaces. The influence of electrolyte, reaction time and voltage on the nanostructure formation is described as well as the transfer to microstructured surfaces. As electrolytes we investigate sulfuric and hydrofluoric acids with different concentrations. The resulting nanostructures reach from nano porosities over amorphous sponge like structures to self-assembled hexagonal nanotubes.

Pheochromocytoma (PC12) Cell Response on Mechanobactericidal Titanium Surfaces.

Titanium is a biocompatible material that is frequently used for making implantable medical devices. Nanoengineering of the surface is the common method for increasing material biocompatibility, and while the nanostructured materials are well-known to represent attractive substrata for eukaryotic cells, very little information has been documented about the interaction between mammalian cells and bactericidal nanostructured surfaces. In this study, we investigated the effect of bactericidal titanium nanostructures on PC12 cell attachment and differentiation—a cell line which has become a widely used in vitro model to study neuronal differentiation. The effects of the nanostructures on the cells were then compared to effects observed when the cells were placed in contact with non-structured titanium. It was found that bactericidal nanostructured surfaces enhanced the attachment of neuron-like cells. In addition, the PC12 cells were able to differentiate on nanostructured surfaces, while the cells on non-structured surfaces were not able to do so. These promising results demonstrate the potential application of bactericidal nanostructured surfaces in biomedical applications such as cochlear and neuronal implants.

Surface nanostructuring of titanium imparts multifunctional properties for orthopedic and cardiovascular applications

Commercially pure titanium (cp-Ti) is a metallic biomaterial used in orthopedic and cardiovascular applications. Here, surface nanocrystalline cp-Ti produced by surface mechanical attrition treatment (SMAT) is shown to exhibit multifunctional properties for orthopedic and cardiovascular applications. Nanocrystallization simultaneously enhanced the stem cell response and fatigue resistance in simulated body fluid of cp-Ti collectively required for load bearing orthopedic applications. Stem cell attachment and proliferation was enhanced by 20% and number of cycles to failure increased by 15% after nanocrystallization. Nanocrystalline Ti was also found to be suitable for cardiovascular applications due to its improved hemocompatibility. A 40% reduction in attachment of platelets and their activation was noted on the surface of nanocrystalline Ti. While high surface hardness and compressive residual stress improved the corrosion-fatigue resistance, the biological response of stem cells and platelets was governed by the physico-electro-chemical properties of the surface oxide on cp-Ti. Modulation in properties of the oxide layer altered the protein adsorption, evaluated by means of electrochemical impedance spectroscopy and direct protein quantification thereby, augmenting the biological response. Taken together, it is demonstrated that surface nanocrystallization by SMAT is a promising step towards producing high performance Ti implants for orthopedic and cardiovascular applications.

Impact of 3D Hierarchical Nanostructures on the Antibacterial Efficacy of a Bacteria-Triggered Self-Defensive Antibiotic Coating.

Titanium is often applied in implant surgery, but frequently implicated in infections associated with bacterial adhesion and growth on the implant surface. Here, we show that hierarchical nanostructuring of titanium and the subsequent coating of resulting topographical features with a self-defensive, antibacterial layer-by-layer (LbL) film enables a synergistic action of hierarchical nanotopography and localized, bacteria-triggered antibiotic release to dramatically enhance the antibacterial efficiency of surfaces. Although sole nanostructuring of titanium substrates did not significantly affect adhesion and growth of Staphylococcus aureus, the coating of 3D-nanopillared substrates with an ultrathin tannic acid/gentamicin (TA/G) LbL film resulted in a 10-fold reduction of the number of surface-attached bacteria. This effect is attributed to the enlarged surface area of the nanostructured coating available for localized bacteria-triggered release of antibiotics, as well as to the lower bacterial adhesion forces resulting in subsided activation of bacterial antibiotic-defense mechanisms when bacteria land on nanopillar tips. The result shows that a combination of 3D nanostructuring with a bacteria-triggered antibiotic-releasing coating presents a unique way to dramatically enhance antibacterial efficacy of biomaterial implants.

On the increasing of adhesive strength of nanotube layers on beta titanium alloys for medical applications

The nanostructuring of titanium and its alloys surfaces is used inter alia for increasing the medical implants osseointegration. Many papers about this topic were published. However, in most cases there were no informations about nanostructures adhesion to the surface, which is crucial from the application point of view. The aim of this study was to prepare nanostructures on titanium beta alloy and optimized its adhesion to the alloy surface. Nanotubes were formed by anodic polarization in electrolyte containing fluoride ions. The composition of the nanotubes was described by X-ray photoelectron spectroscopy. Nanostructures adhesion was tested by pull-of method. The nanotubes on the Ti–36Nb–6Ta beta alloy surface were prepared by anodization. The nanostructures properties were modified by electrochemical process parameters. The adhesion of the nanotubes prepared in this work was satisfactory for implantological applications.

Formation of Titanium Nanostructures on Block Copolymer Templates with Varying Molecular Weights

A novel and simple method for producing mesoporous titanium films and supported titanium nanoparticle hexagonal arrays is presented. During evaporation on block copolymer templates, titanium self-assembles as either a mesoporous film or as a hexagonal close-packed nanodot structure. The morphology of the titanium only depends on the molecular weight of the block copolymer, which results in a remarkable fabrication technique that saves time relative to conventional methods. Analyses using scanning electron microscopy, X-ray reflectometry, and grazing-incidence small-angle X-ray scattering correlate the morphology of the titanium with the buried polymer structure. The mesoporous titanium film exhibited a pore size of approximately 16 nm, with a pore-to-pore distance of 42 nm. The average size of the hexagonally packed nanodots was 60 nm, with a center-to-center distance of 88 nm commensurate with the template features. An analysis of the chemical composition showed that the structures were titanium dioxide,...

Mesenchymal stem cell response to conformal sputter deposited calcium phosphate thin films on nanostructured titanium surfaces

Biomaterial surfaces that can directly induce the osteogenic differentiation of mesenchymal stem cells (MSCs) present an exciting strategy for bone tissue engineering and offers significant benefits for improving the repair or replacement of damaged or lost bone tissue. In this study, titanium nanostructures with distinctive topographical features were produced by radio frequency magnetron sputtering. The response of MSCs to the nanostructured titanium (Ti) surfaces before and after augmentation by a sputter deposited calcium phosphate (CaP) coating has been investigated. The sputtered CaP has the characteristics of a calcium enriched hydroxyapatite surface layer, as determined by X-ray photoelectron spectroscopy and X-ray diffraction studies. The sputter deposited Ti has a polycrystalline surface morphology, as confirmed by atomic force microscopy, and CaP layers deposited thereon (TiCaP) conform to this topography. The effects of these surfaces on MSC focal adhesion formation, actin cytoskeleton organization and Runx2 gene expression were examined. The Ti and TiCaP surfaces were found to promote changes in MSC morphology and adhesion known to be associated with subsequent downstream osteogenic differentiation; however, the equivalent events were not as pronounced on the CaP surface. A significant increase in Runx2 expression was observed for CaP compared to Ti, but no such difference was seen between either Ti and TiCaP, nor CaP and TiCaP. Importantly, the Ti surface engendered the expected contribution of nanoscale features to the MSC response; moreover, the CaP layer when used in combination with this topography has been found to cause no adverse effects in respect of MSC behavior.