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5‐Methoxy‐2‐mercaptobenzamidazole was used to synthesize O‐ethyl‐S‐(5‐methoxy‐1H‐benzo[d]imidazol‐2‐yl) carbonothioate (OESMBIC) by the reaction with chloroacetic acid ethyl ester in a KOH solution. The reaction product (OESMBIC) was characterized using Fourier transform infrared (FTIR), melting point, and 1H‐NMR. The characteristic results prove the formation of the target compound with high purity. Furthermore, the work includes the synthesis of ZnO and TiO2 nanoparticles via chemical methods in the high alkalinity solution. These nanoparticles were used to synthesize two novel nanocomposites named OESMBIC‐ZnO and OESMBIC‐TiO2. The synthesized nanocomposites were characterized by FTIR, SEM, EDX, TEM, and XRD. The results prove that the prepared titanium oxide as nanotubes with diameters ranging between 20 and 35 nm decorated with OESMBIC. The results prove that ZnO in OESMBIC‐ZnO was found as nanorods with different lengths and diameters of 40–65 nm decorated with OESMBIC molecules. The as‐prepared compounds; OESMBIC, OESMBIC‐ZnO, and OESMBIC‐TiO2 were used for the hydrogen storage application using the VTI method. The results prove that the addition of ZnO and TiO2 nanoparticles enhanced the storage ability of OESMBIC as the OESMBIC gave only 0.50 wt% at an equilibrium pressure of 40 bar, while it reached 2.40 and 4.37 wt% at equilibrium pressures of 60 and 75 bar for OESMBIC‐ZnO and OESMBIC‐TiO2, respectively. [ABSTRACT FROM AUTHOR]

Preventing or treating infections at implantation sites where the risk of bacterial contamination is high requires the development of intelligent drug delivery systems. The objective of this work was to develop a production method and characterization of fourth-generation oxide nanotubes on titanium grade 4 surface as a potential drug carrier. This study focused on the anodizing process; physico-chemical characterization using FE-SEM, EDS, and FTIR; in vitro corrosion resistance in an artificial saliva solution; and determining the drug release kinetics of gentamicin sulfate using UV-VIS. The anodizing process was optimized to produce fourth-generation oxide nanotubes in a fluoride-free electrolyte, ensuring rapid growth and lack of order. Results showed that the length of the oxide nanotubes was inversely proportional to the anodizing voltage, with longer nanotubes formed at lower voltages. The nanotubes were shown to have a honeycomb structure with silver particles co-deposited on the surface for antibacterial properties and were capable of carrying and releasing the antibiotic gentamicin sulfate in a controlled manner, following Fick's first law of diffusion. The corrosion resistance study demonstrates that the oxide nanotubes enhance the corrosion resistance of the titanium surface. The oxide nanotubes show promise in enhancing osseointegration and reducing post-implantation complications. [ABSTRACT FROM AUTHOR]

Nanocomposites based on anodic titanium oxide nanotubes with copper oxide nanoparticles were formed and their structural, optical, and electrophysical properties were studied. Defects in the structure of the samples were identified by electron paramagnetic resonance and it was shown that, as a result of copper oxide deposition, CuO nanoparticles were formed on the surface of nanotubes. It was found that the conductivity of the structure decreases by several orders of magnitude with an increase in the number of deposition cycles. It was shown that this effect could be associated with the formation of TiO2/CuO heterojunctions on the nanotube surface. It was shown for the first time that an increase in the content of copper oxide in TiO2/CuxO nanocomposites was accompanied by a decrease in conductivity and an increase in the number of defects. [ABSTRACT FROM AUTHOR]

In this work, we conducted a study of the interaction between DNA and favipiravir (FAV). This chemotherapeutic compound is an antiviral drug for the treatment of COVID-19 and other infections caused by RNA viruses. This paper examines the electroanalytical characteristics of FAV. The determined concentrations correspond to therapeutically significant ones in the range of 50–500 µM (R2 = 0.943). We have shown that FAV can be electro-oxidized around the potential of +0.96 V ÷ +0.98 V (vs. Ag/AgCl). A mechanism for electrochemical oxidation of FAV was proposed. The effect of the drug on DNA was recorded as changes in the intensity of electrochemical oxidation of heterocyclic nucleobases (guanine, adenine and thymine) using screen-printed graphite electrodes modified with single-walled carbon nanotubes and titanium oxide nanoparticles. In this work, the binding constants (Kb) of FAV/dsDNA complexes for guanine, adenine and thymine were calculated. The values of the DNA-mediated electrochemical decline coefficient were calculated as the ratio of the intensity of signals for the electrochemical oxidation of guanine, adenine and thymine in the presence of FAV to the intensity of signals for the electro-oxidation of these bases without drug (S, %). Based on the analysis of electrochemical parameters, values of binding constants and spectral data, intercalation was proposed as the principal mechanism of the antiviral drug FAV interaction with DNA. The interaction with calf thymus DNA also confirmed the intercalation mechanism. However, an additional mode of interaction, such as a damage effect together with electrostatic interactions, was revealed in a prolonged exposure of DNA to FAV. [ABSTRACT FROM AUTHOR]

Titanium implants are one of the most durable and conventional orthopedic and dental implants. The goal of this research is to improve the bio-compatibility of these implants by implementing nano coating of titanium oxide nanotubes (TNT) to enhance bone graft on the implant surface, and reduction of wound healing duration and risk of implant surgery at the same time. For this purpose, the effects of dimension and atomic structure of titanium oxide nanotubes are examined on the surface properties and biological performance and tried to introduce an optimum status of this nano-tubular structure. TNTs were synthesized by anodizing method on the surface of titanium sheets. Dimensions of TNT can be controlled by anodizing process parameters. Heat treatment affects the atomic structure of TNTs. Contact angle measurement as one of the important surface properties was investigated on different dimensions and structures of TNTs, to study human blood's physical interaction with the implant surface. In addition, the quality and quantity of bone material sediment on the surface were examined by SBF test and SEM analysis. Finally, cell culture provided informative data on bone cells' response to these nanotubular coatings by analyzing MTT results and SEM photography of cells. As a result, the optimum dimension and atomic structure of TNTs were defined and the required process parameters were introduced to obtain this state. This setup can be used as an optimum state of TNT as a nano coating on titanium implant with orthopedic functions to enhance the cell adhesion and acquire the highest proliferation rate which means faster bone graft and shorter convalescence.

Environmental pollution is one of the most serious and global problems for humans. Photocatalysis is a promising technology to control environmental pollution via the utilization of semiconductor materials as a photocatalyst. In this study, iron-doped TiO2 nanotubes (Fe/TiNTs) with an increased photocatalytic effect at longer wavelengths compared to undoped TiNTs were used, and the effect on the early hydration and mechanical properties of the main clinker phase tricalcium silicate (C3S) was investigated for the first time. Prior to the incorporation of nanotubes into C3S, it was treated with a supersaturated Ca(OH)2 solution. The addition of 1 and 2 wt.% of Fe/TiNTs into the C3S system significantly accelerated the course of hydration. The degree of hydration for the hydration products after 8 h, 1 d and 7 d have improved. The enhancement of compressive strength after 7 d, 14 d and 28 d were observed compared to normal TiO2 nanotubes (TiNTs). Treating Fe/TiNTs with a supersaturated Ca(OH)2 solution revealed a stronger interaction between Ca2+-ions and nanotubes. Fe/TNTs were synthesized via a modified hydrothermal process. The study shows that Fe/TiNTs can be used as a nanomaterial in cement-based building materials due to their enhanced interaction with the system.

A simple method of synthesis of TiO2 nanotubes (TiNT) loaded with hydroxyapatite (HAP) is described. Such nanotubes find wide applications in various fields, including biomedicine, solar cells, and drug delivery, due to their bioactivity and potential for osseointegration. The Cp-Ti substrate was anodized at a constant voltage of 40 V, with the subsequent heat treatment at 450 °C. The resulting TiNT had a diameter of 100.3 ± 2.8 nm and a length of 3.5 ± 0.04 μm. The best result of the growth rate of HAP in Hanks' balanced salt solution (Hanks' BSS) was obtained in calcium glycerophosphate (CG = 0.1 g/L) when precipitates formed on the bottom and walls of the nanotubes. Structural properties, surface wettability, corrosion resistance, and growth rate of HAP as an indicator of the bioactivity of the coating have been studied. X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), potentiodynamic polarization test (PPC), electrochemical impedance spectroscopy (EIS), and contact angle (CA) measurements were used to characterize HAP-loaded nanotubes (HAP-TiNT). The CA, also serving as an indirect indicator of bioactivity, was 30.4 ± 1.1° for the TiNT not containing HAP. The contact angle value for HAP-TiNT produced in 0.1 g/L CG was 18.2 ± 1.2°, and for HAP-TiNT exposed to Hanks' BSS for 7 days, the CA was 7.2 ± 0.5°. The corrosion studies and measurement of HAP growth rates after a 7-day exposure to Hanks' BSS confirmed the result that TiNT processed in 0.1 g/L of CG exhibited the most significant capacity for HAP formation compared to the other tested samples. [ABSTRACT FROM AUTHOR]

In this work, titanium oxide nanotubes (TNTs) were formed by anodic oxidation on the surface of a Ti–6Al–4V alloy. An electrolyte based on ethylene glycol (EG) and ammonium fluoride (NH4F) was used. Different anodizing periods (10, 20, 30, 40, 50, and 60 min) with a constant potential of 60 V were established. The morphology of the TNT array was observed by scanning electron microscopy (SEM). The adhesion strength of the TNTs to the Ti–6Al–4V surface was evaluated using nanoscratch tests. The critical load of the different TNT layers was determined from the analysis of the groove of the nanoindenter path. It ranged from 0 mN for the samples exposed to 10 min of anodization to 47.0 ± 3.0 mN for samples exposed to 50 min. These results indicate the TNT layers formed at 50 min presented the best substrate adhesion among the specimen tested. [ABSTRACT FROM AUTHOR]

Environmental pollution is one of the most serious and global problems for humans. Photocatalysis is a promising technology to control environmental pollution via the utilization of semiconductor materials as a photocatalyst. In this study, iron-doped TiO2 nanotubes (Fe/TiNTs) with an increased photocatalytic effect at longer wavelengths compared to undoped TiNTs were used, and the effect on the early hydration and mechanical properties of the main clinker phase tricalcium silicate (C3S) was investigated for the first time. Prior to the incorporation of nanotubes into C3S, it was treated with a supersaturated Ca(OH)2 solution. The addition of 1 and 2 wt.% of Fe/TiNTs into the C3S system significantly accelerated the course of hydration. The degree of hydration for the hydration products after 8 h, 1 d and 7 d have improved. The enhancement of compressive strength after 7 d, 14 d and 28 d were observed compared to normal TiO2 nanotubes (TiNTs). Treating Fe/TiNTs with a supersaturated Ca(OH)2 solution revealed a stronger interaction between Ca2+-ions and nanotubes. Fe/TNTs were synthesized via a modified hydrothermal process. The study shows that Fe/TiNTs can be used as a nanomaterial in cement-based building materials due to their enhanced interaction with the system. [ABSTRACT FROM AUTHOR]

Titanium implants are one of the most durable and conventional orthopedic and dental implants. The aim of this research was to improve the bio-compatibility of these implants by implementing nano-dimension coating of titanium oxide nanotubes (TNT). For this purpose, the effect of dimension and atomic structure of titanium oxide nanotubes on the surface properties and biological performance were examined. TNTs were synthesized by anodizing method on the surface of titanium sheets. Dimension of TNT was controlled by anodizing process parameters. Heat treatment affected the atomic structure of TNTs. Contact angle measurement as one of the important surface properties was conducted on different dimensions and structures of TNTs, to study human blood's physical interaction with the implant surface. In addition, the quality and quantity of bone material sediment on the surface were examined by SBF test and SEM analysis. Finally, cell culture provided informative data on bone cells' response to these nanotubular coatings by analyzing MTT results and SEM photography of cells. As a result, the optimum dimension and atomic structure of TNTs were defined and the required process parameters were introduced to obtain this state. This setup may be used as an optimum state of TNT as a nano-dimension coating on titanium implant with orthopedic functions to enhance the cell adhesion and acquire the highest proliferation rate. [ABSTRACT FROM AUTHOR]

Titanium surface treated with titanium oxide nanotubes was used in many studies to quantify the effect of surface topography on cell fate. However, the predicted optimal diameter of nanotubes considerably differs among studies. We propose a model that explains cell adhesion to a nanostructured surface by considering the deformation energy of cell protrusions into titanium nanotubes and the adhesion to the surface. The optimal surface topology is defined as a geometry that gives the membrane a minimum energy shape. A dimensionless parameter, the cell interaction index, was proposed to describe the interplay between the cell membrane bending, the intrinsic curvature, and the strength of cell adhesion. Model simulation shows that an optimal nanotube diameter ranging from 20 nm to 100 nm (cell interaction index between 0.2 and 1, respectively) is feasible within a certain range of parameters describing cell membrane adhesion and bending. The results indicate a possibility to tune the topology of a nanostructural surface in order to enhance the proliferation and differentiation of cells mechanically compatible with the given surface geometry while suppressing the growth of other mechanically incompatible cells. [ABSTRACT FROM AUTHOR]

Atherosclerosis lesions are described as the formation of an occlusive wall-vessel plaque that can exacerbate infarctions, strokes, and even death. Furthermore, atherosclerosis damages the endothelium integrity, avoiding proper regeneration after stent implantation. Therefore, we investigate the beneficial effects of TiO2 nanotubes (NTs) in promoting the initial response of detrimental human atherosclerotic-derived endothelial cells (AThEC). We synthesized and characterized NTs on Ti6Al4V by anodization. We isolated AThEC and tested the adhesion long-lasting proliferation activity, and the modulation of focal adhesions conducted on the materials. Moreover, ultrastructural cell-surface contact at the nanoscale and membrane roughness were evaluated to explain the results. Our findings depicted improved filopodia and focal adhesions stimulated by the NTs. Similarly, the NTs harbored long-lasting proliferative metabolism after 5 days, explained by overcoming cell-contact interactions at the nanoscale. Furthermore, the senescent activity detected in the AThEC could be mitigated by the modified membrane roughness and cellular stretch orchestrated by the NTs. Importantly, the NTs stimulate the initial endothelial anchorage and metabolic recovery required to regenerate the endothelial monolayer. Despite the dysfunctional status of the AThEC, our study brings new evidence for the potential application of nano-configured biomaterials for innovation in stent technologies. [ABSTRACT FROM AUTHOR]

As a new sustainable energy utilization way, triboelectric nanogenerators (TENGs) have attracted increasing attention in recent years. Herein, a new TiO2 nanotube coating based TENG (TNC‐TENG) with corrosion resistance and self‐healable electrical output properties for energy harvesting is developed. The inorganic coating is prepared by anodic oxidation (AO) and fluoridation with titanium. The TiO2 nanotube coating based TENG has a current output of 17.4 µA and a voltage output of 220 V. The fluorinated titanium oxide nanotubes coating has good hydrophobicity. When the fluorine composition on the coating surface is damaged by plasma, the triboelectric current decreases to 7 µA. The self‐healable hydrophobicity and electrical output property are achieved by transferring loaded perfluorosilane to the damaged surface. In addition, the electric energy generated in the triboelectrification can improve the anticorrosion performance for metal matrix by cathodic protection. Based on the corrosion resistance and self‐healing properties, the TNC‐TENG has potential applications in the field of energy collection, energy supply, and corrosion protection. [ABSTRACT FROM AUTHOR]

Titanium has proven to be a game-changing biomaterial in biomedical engineering. Titanium and its alloys offer superior properties such as machinability, mechanical strength, biocompatibility, and corrosion resistance, making them indispensable for safer and more efficient biomedical treatments. While commercially pure titanium (Cp-Ti) is an exceptional material for medical applications, it has some limitations. Allergic reactions can manifest as localized inflammation around the implant, and corrosion compromises implant stability. Corrosion starts with cracking from the surface and disrupts the protective passive oxide layer when touching body fluids, and failure occurs. This study utilized a combination of techniques including grain refinement of Cp-Ti via equal channel angular pressing (ECAP), two-step anodization (for creating titanium oxide nanotubes coatings), annealing at 450°C and 570°C, and immersion in simulated body fluid (SBF) to create a Hydroxyapatite (HA) film coating. These methods addressed various challenges and provided a positive approach to improving corrosion behavior. The microstructure of Nano-Ti was evaluated by Transmission Electron Microscopy (TEM). The morphology of the as-anodized samples and corroded areas were investigated using field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The crystalline phases of titanium nanotubes (TNTs) were evaluated through X-ray diffraction (XRD). The presence of hydroxyapatite particles was analyzed and characterized by FESEM coupled with Energy Dispersive Spectroscopy (EDS) and Fourier Transform Infrared-Attenuated Total Reflection (FTIR-ATR). The corrosion behavior was evaluated using a potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS). Results indicated that grain refinement and successive surface modifications significantly impact corrosion performance. The nanostructured (Nano-Ti) sample, after the final modification stage, exhibited an approximately 11-fold decrease in corrosion rate and over a 450-fold rise in polarization resistance (7.4 MΩ) compared to as-anodized Cp-Ti sample and a 7-fold increase in its Cp-Ti counterpart, and showed excellent adhesion strength compared to other samples. [Display omitted] • The Nano-Ti samples reduce localized corrosion and prevent pit corrosion. • Surface modification in Nano-Ti increases the Rp and decreases the CR. • A defect-free HA-layer in Nano-Ti increases considerably overall resistance. • Hydroxyapatite coating increases total resistance in low frequencies. • The adhesion strength of the metal/TNT interface in Nano-Ti is significantly more than Cp-Ti. [ABSTRACT FROM AUTHOR]

In this work, different surface treatments were investigated to improve the adhesion between grade 5 titanium alloy and carbon fibre-reinforced PEEK composites for aerospace applications. Three types of processes were compared: mechanical treatment (MT), carried out by sander with #80 grit sandpaper, chemical treatment, using a silane coupling agent (SIL) and electrochemical treatment, performed by anodic oxidation. The latter was performed by using an ethylene glycol solution composed of 0.5%wt of ammonium fluoride (NH 4 F) and variable volume content of deionized water: 5%v/v, 20 % v/v, 50 % v/v. The ammonium fluoride content was fixed, while the ethylene glycol percentage depend on the variation of water volume. Two values of electric potential were evaluated: 30V and 50V. Finally, for each potential and water content, three different anodizing times were studied: 10 min, 30 min, and 60 min. Morphology studies were performed through Scanning electron microscopy to evaluate how the anodizing parameters could affect the shape of the nanotubes (NTs) layers. Moreover, short beam shear tests were carried out to evaluate the achieved improvement given by the different surface treatments. [ABSTRACT FROM AUTHOR]

A simple method of synthesis of TiO2 nanotubes (TiNT) loaded with hydroxyapatite (HAP) is described. Such nanotubes find wide applications in various fields, including biomedicine, solar cells, and drug delivery, due to their bioactivity and potential for osseointegration. The Cp-Ti substrate was anodized at a constant voltage of 40 V, with the subsequent heat treatment at 450 °C. The resulting TiNT had a diameter of 100.3 ± 2.8 nm and a length of 3.5 ± 0.04 μm. The best result of the growth rate of HAP in Hanks’ balanced salt solution (Hanks’ BSS) was obtained in calcium glycerophosphate (CG = 0.1 g/L) when precipitates formed on the bottom and walls of the nanotubes. Structural properties, surface wettability, corrosion resistance, and growth rate of HAP as an indicator of the bioactivity of the coating have been studied. X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), potentiodynamic polarization test (PPC), electrochemical impedance spectroscopy (EIS), and contact angle (CA) measurements were used to characterize HAP-loaded nanotubes (HAP-TiNT). The CA, also serving as an indirect indicator of bioactivity, was 30.4 ± 1.1° for the TiNT not containing HAP. The contact angle value for HAP-TiNT produced in 0.1 g/L CG was 18.2 ± 1.2°, and for HAP-TiNT exposed to Hanks’ BSS for 7 days, the CA was 7.2 ± 0.5°. The corrosion studies and measurement of HAP growth rates after a 7-day exposure to Hanks’ BSS confirmed the result that TiNT processed in 0.1 g/L of CG exhibited the most significant capacity for HAP formation compared to the other tested samples.

Titanium and its alloys have been widely used for orthopedic and dental implants. However, implant failures often occur due to the implant-related bacterial infections. Herein, titanium oxide nanotubes (TNTs) with an average diameter of 75 nm were formed by anodizing on the surface of titanium, and subsequently gold (Au) nanoparticles were deposited on TNTs by magnetron sputtering (Au@TNTs). The antibacterial study shows that TNTs surface decorated with Au nanoparticles exhibits the preferable effect in restricting the growth of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) even under dark conditions, and the antibacterial rates reached 84% and 75%, respectively. In addition, the constructed film showed no cytotoxicity. Such a selective bactericidal effect of Au@TNTs samples might be attributed to the photocatalytic memory effect, which provides a new insight in the designing of antibacterial surfaces for biomedical application. [ABSTRACT FROM AUTHOR]

This work primarily focused on the design of electrochemical and modified analytical sensors by two highly conductive and powerful modifiers including titanium oxide nanotubes/single wall carbon nanotubes (TiO2-SWCNTs) and 1-hexyl 3-methyl imidazolium hexafluorophosphate (HMH) to detect bisphenol A (BPA) in the well water, municipal water, and soft drinks. In this regard, carbon paste electrode (CPE) was amplified with HMH and TiO2-SWCNTs, and then it was utilized for voltammetric sensing of bisphenol A in aqueous solution. The ability of sensor for determination of bisphenol A was assessed by chronoamperometric, cyclic voltammetric and differential pulse voltammetric (DPV) methods. At optimal condition of pH=5.0, TiO2-SWCNTs/HMH/CPE offered a powerful catalytic effect on oxidation signal of bisphenol A and enhanced its current about 7.77 times. Using DP voltammetric method, the TiO2-SWCNTs/HMH/CPE showed a linear dynamic range of 3.0 nM – 450 µM, and a good limit of detection of 1.0 nM. Moreover, TiO2-SWCNTs/HMH/CPE provided acceptable recovery data for determination of bisphenol A in real samples such as well water, Urban water and soft drink. [ABSTRACT FROM AUTHOR]

In the present work, an easy and scalable method to prepare lithium titanium oxide nanotubes with stable and reversible lithium storage properties is reported. This material could be an excellent candidate for lithium recovery from aqueous solutions or have a direct application as Li‐ion batteries electrodes in a circular economy perspective. Vertically oriented anatase nanotubes are grown by anodic oxidation in an ethylene glycol‐based electrolyte. Then, the nanotubes are hydrothermally converted into a mixed lithium titanate. Morphological and crystallographic characterizations confirm the successful shape‐preserving conversion after which the nanotubes are subjected to electrochemical cycling. XRD and XPS analyses confirm a significant lithium uptake after cycling, and its recovery is investigated by means of an acidic treatment. While allowing for an almost complete recovery of the lithium integrated in their structure, the nanotubes also showed excellent morphological and structural stability proving to be excellent candidates for lithium recovery purposes. [ABSTRACT FROM AUTHOR]

Pt nanoparticles exhibit good catalytic performance for the hydrogenation of phenol. However, the supported Pt nanoparticles often encounter leakage and growth in the reaction process. Herein, a confined Pt catalyst is elaborately designed and prepared by atomic layer deposition template-assisted method. The specific preparation process is as follows. ZnO single crystal nanowires are used as the sacrificed templates, and the sequential deposition of Pt nanoparticles (20 cycles) and TiO2 layer (300 cycles) on ZnO nanowires templates by atomic layer deposition (ALD) is conducted, followed by removal of ZnO nanowires using acetic acid. The characterization results demonstrate that Pt nanoparticles have been imbedded into the inter wall of titanium oxide nanotubes. Compared with the supported Pt nanoparticles, the confined Pt nanoparticles exhibit enhanced catalytic activity and stability for phenol hydrogenation. TEM, XPS and CO chemisorption characterization results confirm that the confined catalyst possesses stronger Pt-TiO2 interaction, resulting in the improved catalytic performance. Present here is the preparation of confined Pt catalyst by atomic layer deposition for the enhanced catalytic performance of the phenol hydrogenation. The high activity and good stability under the mild reaction conditions of this confined catalyst prepared by atomic layer deposition may have application prospect in industrialization. [ABSTRACT FROM AUTHOR]

The surface of titanium oxide nanotubes (TiNTs) was chemically modified after synthesis to determine their influence on the non-isothermal crystallization of polypropylene nanocomposites compared to pristine titanium oxide nanotube-reinforced systems. Pimelic acid (PA) was used to carry out the chemical functionalization (TiNT-PA). The FTIR spectrum revealed that PA successfully bound to the TiNT surface due to the appearance of new vibrational bands at 29834, 2868, 1578, and 1407 cm−1. After the functionalization process, the morphology of TiNT remained unchanged according to TEM images. In addition, the new filler showed high thermal stability when subjected to TGA (between 320 and 450 °C). DSC studies were carried out to investigate the influence of this chemical functionalization on the crystallization behavior of the nanocomposites. The nanocomposites with the modified TiNTs showed more significant shifts of the crystallization temperature peaks with large heterogeneous nucleation. According to Jeziorny's analysis, the effect of fillers was only observed for the functionalized nanotubes with the lowest crystallization times, while the systems with pristine TiNT practically remained the same. This behavior is attributable to the fact that the acid's presence reduced agglomeration and improved the efficiency of the nucleation activity. Mo's model results confirmed that the heat flux requirements of the crystallization process were lower for the nanocomposites reinforced with TiNT-PA as they act better as heterogeneous nuclei. Then, they provide the surface area to serve as a nucleation center and help crystallize the polypropylene due to the aliphatic chain of the organic molecule. [ABSTRACT FROM AUTHOR]

Zinc ions (Zn2+) are a highly potent bioactive factor with a broad spectrum of physiological functions. In situ continuous and controllable release of Zn2+ from the biomaterials can effectively improve the biocompatibility and antibacterial activity. In the present study, inspired by the adhesion and protein cross-linking in the mussel byssus, with the aim of improving the biocompatibility of titanium, a cost-effective one-step metal–catecholamine assembly strategy was developed to prepare a biomimetic dopamine–Zn2+ (DA-Zn2+) coating by immersing the titanium oxide nanotube (TNT) arrays on the titanium surface prepared by anodic oxidation into an aqueous solution containing dopamine (DA) and zinc ions (Zn2+). The DA-Zn2+ coatings with the different zinc contents exhibited excellent hydrophilicity. Due to the continuous release of zinc ions from the DA-Zn2+ coating, the coated titanium oxide nanotubes displayed excellent hemocompatibility characterized by platelet adhesion and activation and hemolysis assay. Moreover, the DA-Zn2+-coated samples exhibited an excellent ability to enhance endothelial cell (EC) adhesion and proliferation. In addition, the DA-Zn2+ coating can also enhance the antibacterial activity of the nanotubes. Therefore, long-term in situ Zn2+-releasing coating of the present study could serve as the bio-surfaces for long-term prevention of thrombosis, improvement of cytocompatibility to endothelial cells, and antibacterial activity. Due to the easy operation and strong binding ability of the polydopamine on various complicated shapes, the method of the present study can be further applied to other blood contact biomaterials or implantable medical devices to improve the biocompatibility.

The relations and correlation between the physicochemical characteristics of a chemical compounds and the molecular structure connectivity of the same compound are used in quantitative structure activity and property relationship studies (QSAR/QSPR) by using the appropriate graph‐theoretical techniques. Szeged index has been extensively studied for modeling physicochemical properties of organic compounds acting as drugs or possess pharmacological activity. In this paper, we consider the two‐dimensional lattices of titanium oxide nanotubes TiO2. We compute several Szeged‐type indices such as vertex Szeged, edge Szeged, edge‐vertex Szeged, total Szeged, Padmaker–Ivan, revised Szeged and revised‐edge Szeged indices of these graphs. We define new types of cuts that are different from orthogonal cuts and can be used to obtain Szeged‐type results of titania nanotubes. [ABSTRACT FROM AUTHOR]

Successive ionic layer adsorption and reaction (SILAR) method has been used to decorate Prussian blue (PB) on tungsten-doped titanium oxide nanotubes (WTiO2). Scanning electron microscopy (SEM), X-ray diffraction (XRD), EDX, and UV-Vis-DRS methods have been used to characterize the morphology, phase composition, elemental composition, and optical properties of the samples prepared. The PB/WTiO2 samples prepared were then used as photoanodes in photoelectrochemical water splitting to yield hydrogen. The morphology, optical property, and photoelectrochemical performance of the prepared samples were highly affected by the SILAR deposition cycle, according to the results obtained. The sample with PB deposited in 9 SILAR cycles (sample S9) showed the highest photocurrent value (0.118 mA/cm2) under illumination. This enhancement is mostly due to visible light harvesting and reduced recombination of photo-generated electron-hole pairs, resulting from the synergistic effect of the heterojunction and the well-organized morphology of WTiO2. [ABSTRACT FROM AUTHOR]

The relations between the physico‐chemical properties of a chemical compounds its molecular structure properties are used in quantitative structure activity and property relationship studies by using graph‐theoretical techniques. The Wiener polarity index is the number of unordered pairs of vertices lying at distance 3 in a graph. This index is correlated to the cluster coefficient of chemical networks. The Wiener polarity index has been used to exhibit quantitative structure–property relationships in a series of acyclic and cycle‐containing hydrocarbons. In this paper, we consider three variants of the graph of titanium oxide TiO2, that is, two‐dimensional lattice, nanotubes and nanotorus. For all these graphs, we compute the number of pairs of vertices lying at distance one, two and three. Using this information, we compute the Wiener polarity index and leap Zagreb indices of these graphs. [ABSTRACT FROM AUTHOR]

Magnetic nanocomposite UIO-66-NH2-MnFe2O4-TiO2-TiNT was synthesized for synchronous and selective adsorption of Cd(II) heavy metal and Methyl orange (MO) dye pollutants in the textile wastewater. XRD, SEM, FT-IR, BET and VSM techniques were used. The best conditions were obtained for the independent variables in the synchronous adsorption of Cd(II) and methylene orange (MO) dye for the initial metal concentration, initial MO concentration, pH, adsorbent amount and acid-promoted molar ratio 500 (mg/l), 146.8 (mg/l), 5.5, 0.159 (gr) and 46 respectively. After the adsorption, the adsorbent was removed from the solution well with an external magnetic field. [ABSTRACT FROM AUTHOR]

Photocatalysts are part of key strategies to enable green fuel. Photocatalysis and water splitting could be a promising solution to challenges associated with the intermittent nature of sunlight as a huge energy source on Earth. In this study, photo-electrochemical performance and behavior of mixed-phase titanium oxide and iron oxide heterojunction (Ti-TiO x (High-voltage)-FeO x electrode) are compared to the photo-electrochemical performance and behavior of titanium oxide nanotubes with the rutile phase and iron oxide heterojunction (TiO x -nanotubes (H 2 SO 4 /KF)-FeO x electrode). The results of photo-electrochemical experiments show that the application of stabilization potential and the presence/absence of dissolved oxygen could not be considered as significant factors affecting the photo-electrochemical properties of the Ti-TiO x (High-voltage)-FeO x and TiO x -nanotubes (H 2 SO 4 /KF)-FeO x electrodes. The Ti-TiO x (High-voltage)-FeO x electrode shows an anodic photo-electrochemical response in wavelengths shorter than 530 nm and cathodic photo-electrochemical response in wavelengths longer than 530 nm. However, the Ti-nanotubes (H 2 SO 4 /KF)-FeO x electrode consistently exhibits the anodic photo-electrochemical response. Both of the prepared heterojunctions are further characterized through Scanning Electron Microscopy, Energy-dispersive X-ray Spectroscopy, Diffuse Reflectance UV–Vis Spectroscopy, X-ray Diffraction, and Attenuated Total Reflectance Spectroscopy methods. These experiments show that despite different morphologies observed in SEM imaging data, the deposited iron oxide layers on both mixed-phase titanium oxide and titanium oxide nanotubes share the same hematite phase structure. However, only iron oxide electro-deposited on the surface of the mixed-phase titanium oxide, which contains both anatase and rutile phases, with vacant sites of oxygen, exhibits un-expected anodic and cathodic photo-electrochemical responses. Furthermore, according to the results of the characterization and photo-electrochemical investigations, the different chemical environment of mixed-phase titanium oxide, and the possible formation of different types of heterojunction structures in mixed-phase titanium oxide and iron oxide, in contrast to the titanium oxide nanotubes and iron oxide, might be considered the possible discernible reasons for the observed different photo-electrochemical responses. This paper sheds new light on photo-electrochemistry of iron oxide/mixed-phase titanium oxide heterojunction for possible solar energy conversion. In this study, photo-electrochemical performance and behavior of mixed-phase titanium oxide and iron oxide heterojunction were investigated. Image 1 • Photo-electrochemical studies conducted on mixed-phase titanium oxide and iron oxide. • The photocatalysts showed a cathodic response contrary to n-type nature of hematite. • Mixed-phase TiO 2 imposes different chemical conditions on iron oxide photocatalyst. • Photo-electrochemistry of the compound confirms the energy band level. [ABSTRACT FROM AUTHOR]

The use of titanium oxide nanotubes in the hydrogen evolution reaction (HER) was studied. Nanotubes were grown on titanium substrates through the anodizing process. Using the X-ray diffraction technique, the structure of the samples was determined. The surface roughness values of the samples after the anodizing process were determined by applying atomic force microscopy. The reaction kinetics were studied through electrochemical impedance spectroscopy and potentiodynamic polarization curves at repeated oxidation-reduction cycles, using a 0.5 M sulfuric acid solution as the electrolyte. Stability in contact with the solution and the establishment of a balance in the load transfer coefficients and the kinetics as a function of hydrogen production cycles were determined using electrochemical impedance spectroscopy and potentiodynamic curve techniques. [ABSTRACT FROM AUTHOR]

Featured Application: Water availability is imperative to the Maltese islands. The lack of natural freshwater bodies and a climate characterized by low annual rainfall and high temperatures increase the pressure on the available freshwater resources to the ever-increasing population. The treatment of greywater to be used as second-class water for WC flushing and agricultural purposes could alleviate the demand put on the desalination plants and groundwater resources of the islands. In recent years, the application of titanium-dioxide-based photocatalytic systems has sparked a great deal of interest within the scientific community, due to its potential in removing pollutants and bacteria from air and water systems. The study at hand aims to provide an insight on the efficacy of TiO2 nanostructures having different morphologies to be used for this purpose and thus identify the ideal TiO2 surface morphology for implementation in a microscale photocatalytic greywater treatment system. The application of titanium oxide nanotubes for the removal of contaminants from freshwater is a rapidly growing scientific interest, especially when it comes to water conservation strategies. In this study we employed four different titanium oxide nanotube surfaces, prepared by a two-electrode anodic oxidation. Two of the surfaces were synthesised in aqueous media, while the other two surfaces were synthesised in ethylene glycol. One of the arrays synthesised in the organic medium was impregnated with silver nanoparticles, while the remaining surfaces were not. The chemical reactivity of the various surfaces was assessed using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as free electron sensitive probe molecules, in parallel with tannic acid degradation and copper ion reducing capacity. The potential antimicrobial activity of the surfaces was assessed against a panel of microorganisms composed of yeast, fungi, Gram-positive and Gram-negative bacteria. Field emission scanning electron microscopy revealed that surfaces produced in the aqueous medium had a smaller tube length and a smaller tube diameter. It was noted that one of the materials using sodium sulfate as the supporting electrolyte had the most irregular nanostructure morphology with tubes growing to the side rather than vertically. The structural variation of the surfaces directly reflected both the chemical and biological activity, with the nanotubes formed in ethylene glycol showing the fastest rates in the stabilization of DPPH and ABTS radicals, the fastest tannic acid decomposition under various pH conditions and the fastest metal reducing activity. Furthermore, the surface containing silver and its bare counterpart showed the most effective antimicrobial activity, removing approximately 82% of Gram-negative bacteria, 50% of Gram-positive bacteria, 70% of yeast and 40% of fungi, with Gram-negative bacteria being the most susceptible to these surfaces. [ABSTRACT FROM AUTHOR]

The presence of Magnéli phases in titanium oxide nanotubes (NTs) can open up frontiers in many applications owing to their electrical and optical properties. Synthesis of NTs with Magnéli phases have posed a challenge due to the degradation and loss of morphology in NTs upon high-temperature treatments (>600 °C) in a reducing environment. This study reports on the synthesis of anodically formed NTs containing Magnéli phases through a double annealing route: oxygen (O2) annealing followed by annealing in 2% hydrogen with a nitrogen balance (2%H2-N2). The nucleation, growth, and transformation of anodized amorphous NTs into crystalline phases was investigated. The NTs obtained through this route were highly ordered and composed of mixed phases of anatase, rutile, and the Magnéli phase (Ti4O7). Experimental results from scanning electron microscopy (SEM), X-ray diffraction (XRD), scanning transmission electron microscopy (S/TEM), and Raman spectroscopy were combined with first principle calculations to develop an understanding of the sequential phase transformations during annealing. A predictive model was developed using density functional theory (DFT) to potentially predict the titanium oxides formed and their stability with reference to the mole fraction of oxygen. The change in the density of states (DOS), band structure, optical properties, and stability of phases are also discussed using DFT simulations. The combination of experimental characterization and modelling helped to understand the nucleation of anatase and rutile and the reorganization of these phases to form Magnéli phases on the anodized amorphous NTs through annealing treatment. [ABSTRACT FROM AUTHOR]

In the present work, we have investigated the influence of temperature on the morphology of anodically produced self-organized titanium oxide nanotubes (TiNTs). TiNTs are synthesized by two-step anodization in ethylene glycol-based electrolytes containing ammonium fluoride and deionized water. Experiments are performed at constant anodization voltage of 50 V for 2 h. An investigation by the SEM images reveals that if the temperature is kept constant during the anodizing experiment, variation in the average tube diameter is significantly reduced. Degree of pore arrangement, pore size and oxide thickness increased with the increase in temperature as observed at a range of electrolyte temperatures fixed between 5°C and 40°C. However, if the temperature is not controlled during the anodization experiment, then due to the exothermic nature of the reactions to the formation of TiNTs, the temperature of the electrolyte continues to increase. This variation in electrolyte bath temperature introduces strong variations in tube diameter (10–160 nm) along the length of the tubes. Current profiles, recorded during the anodization experiments, predict the effect of constant and varying experimental temperatures as well. In both cases, XRD results show the complete anatase crystal structure of nanotubes upon annealing at 450°C. The present work highlights the importance of fixed processing temperature during the anodization experiments in order to develop an ordered array of nanotubes with a uniform tube diameter. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the photoelectrochemical performance and behavior of mixed-phase titanium oxide, which was prepared through a high voltage method, and a manganese oxide heterojunction (Ti–TiOx–MnOx). In addition, the obtained results for Ti–TiOx–MnOx have been compared to the photoelectrochemical performance and behavior of titanium oxide nanotubes with a rutile phase, which is widely accepted as a reference due to the well-known photoelectrochemical performance, and manganese oxide heterojunction (Ti-nanotube–MnOx). The photoelectrochemical experiments showed that the application of stabilization potential and the presence and absence of dissolved oxygen significantly affected the photoelectrochemical properties of the Ti–TiOx–MnOx electrode. Exposing the Ti–TiOx–MnOx electrode to a stabilization potential of 1200 mV in the presence or absence of dissolved oxygen altered its oxidative photoelectrochemical response to a reductive photoelectrochemical response. However, the Ti-nanotube–MnOx electrode was not sensitive to the aforementioned conditions and always exhibited the same oxidative photoelectrochemical response. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, diffuse reflectance UV-Vis spectroscopy, X-ray diffraction, and attenuated total reflectance spectroscopy were exploited to characterize the prepared electrodes. These experiments showed that the deposited manganese oxide layer on both electrodes has a layered structure without long-range order. However, only the manganese oxide on the surface of the mixed-phase titanium oxide exhibited the expected photoelectrochemical response according to previous studies conducted on manganese oxide. Furthermore, according to the characterization experiments, it can be concluded that the different chemical environments of mixed-phase titanium oxide, containing both anatase and rutile phases, with oxygen vacancy sites may be one discernible reason for the observed different photoelectrochemical response of manganese oxide compared to titanium oxide nanotubes with a rutile phase. [ABSTRACT FROM AUTHOR]

• TiNT-TEPA was synthesized as filler particles for blended Pebax/PEG600 nanocomposite membrane based on DOE and RSM methods. • Adsorption capacity of as-synthesized and functionalized nanotubes investigated. • Nanocomposite membranes' CO 2 permeability and CO 2 /CH 4 selectivity considerably increased compared with neat membrane. • Effect of operating temperature and transmembrane pressure were studied for single and mixed gases. Raw and tetraethylene pentamine (TEPA) functionalized titanium oxide nanotubes (TiNTs) were used as filler particles to prepare nanocomposite membranes. Polyethylene glycol (PEG) was blended with the Pebax-1657 as matrix and incorporated by TiNT-TEPA to prepare Pebax-1657/PEG/TiNT-TEPA nanocomposite membranes based on Response Surface and Central Composite Design methods of experimental design. The TiNT-TEPA and the Pebax/PEG/TiNT-TEPA were characterized using TEM, FESEM, SEM, FTIR or ATR-FTIR, XRD (EDS) and mechanical strength analysis. CO 2 adsorption capacity of TiNTs and TiNT-TEPA-70% were found as 0.71 and 4.2 mmol/g, respectively. CO 2 permeability and ideal selectivity of optimum (in term of separation performance) membrane, as Pebax (7 wt.%) /PEG (7.5 wt.%)/TiNT-TEPA (3 wt.%), were increased by 67.7 and 11.7%, respectively, compared with the neat Pebax membrane. The optimum membrane's CO 2 permeability and CO 2 /CH 4 ideal selectivity were investigated at operating temperatures of 20–45 °C and reveled 18.5 and −9% changes, respectively. Its transmembrane pressures increment form 4 to 10 bar for single and CO 2 (50)/CH 4 (50) mixed gas resulted in CO 2 permeability and CO 2 /CH 4 ideal selectivity enhancements by 19 and 20%, respectively. The optimum membranes' mixed gas separation performance were found lower than that of single pure gases at the same operating condition. [ABSTRACT FROM AUTHOR]

Conductive Ti-oxide thin films are produced using a reactive sputtering and post-annealing process. The lowest resistivity of Ti-oxide thin films (2.30 × 10-2 Ω-cm) can be achieved after annealing for 1 h at 400 °C in ambient O2. Additionally, the Hall measurement results indicate that the carrier concentration increases during the initial 1-h annealing process before decreasing during subsequent annealing. By curve fitting the Ols core-level peaks in the x ray photoelectron spectroscopy (XPS) spectrum of the annealed Ti-oxide thin films, we found that the oxygen (O) vacancy concentration monotonically increases with annealing time, which differs from the behavior of the carrier concentration regarding annealing time. This means that the O-vacancy mechanism alone cannot explain the formation of carriers in Ti-oxide thin films. By curve-fitting core-level Ti peaks in the XPS spectrum of annealed Ti-oxide thin films, a Ti3+-to-Ti4+ substitution reaction in the TiO2 phase of the Ti-oxide thin film after annealing plays the dominant role in the formation of conduction carriers. Instead of the O-vacancy mechanism, the Ti3+-to-Ti4+ substitution mechanism can explain the concentration of carriers in Ti-oxide thin films following annealing. [ABSTRACT FROM AUTHOR]

In this study, apatite formation ability on TiO 2 nanotubes (TNTs) synthesized by anodizing process were compared with TNTs decorated by MnO nanoparticles. The MnO nanoparticles used for decoration process were fabricated via thermal decomposition method. At first, it was strived to find the optimal condition of anodizing process and the effect of applied voltages (15 V, 20 V, and 25 V) and process times (15 min, 20 min, and 25 min) on the diameter of the synthesized TNTs was investigated. Results of microscopic characterizations showed that the completely uniform structure of nanotubes with a diameter in the range of about 100–130 nm was achieved after 20 min of anodizing process at an applied voltage of 25 V. In the next step, MnO nanoparticles were synthesized by thermal decomposition method. The effect of heating rate of 2 °C/min and 20 °C/min on the size and morphology of nanoparticles was investigated. The results showed that higher heating rate of the synthesis process has led to a decrease in MnO particle size with a more uniform morphology. After that, the TNTs surfaces were decorated with MnO nanoparticles using solvothermal process and the effect of MnO concentration was investigated in the solvothermal process. The bioactivity results of the specimens in simulated body fluid (SBF) showed that the decorated TNTs with higher amounts of MnO nanoparticles exhibited the highest ability to form apatite compared to the decorated TNTs with lower amounts of MnO nanoparticles and un-decorated TNTs. [ABSTRACT FROM AUTHOR]

This study aimed to fabricate a novel TiNT-RuO2 electrocatalyst to produce active chlorine with the capacity to oxidize recalcitrant organic matter. Titanium oxide nanotubes (TiNTs) were first grown via Ti foil anodization in potentiostatic mode in an ethylene glycol solution containing H2O and NH4F and then annealed at 450°C in air. RuO2 nanoparticles were deposited on the TiNTs using a hybrid strategy that included pulsed electrodeposition of the Ru nanoparticles, followed by thermal treatment. X-ray diffraction (XRD) only revealed peaks related to metallic Ti and anatase (TiO2) for the TiNTs, whereas additional peaks associated with the tetragonal RuO2 structure were shown for TiNT-RuO2. Scanning electron microscopy showed a well-organized structure for the TiNTs with an average inner diameter of approximately 185 nm for the NTs, while RuO2 nanoparticles (size <10 nm) were homogenously deposited on the walls and around the openings of the TiNTs. TiNT-RuO2 preferred the active chlorine formation over oxygen evolution owing to the presence of the RuO2 nanoparticles. Rapid degradation testing revealed complete elimination of picloram (PCL) in 2 h when 10 mA cm−2 was imposed on the TiNT-RuO2, whereas 48% of the 2,4-dichlorophenoxyacetic acid (2,4-D) was removed under the same conditions using the electro-generated active chlorine on the TiNTs. [ABSTRACT FROM AUTHOR]

We fabricated a humidity responsive film comprising a bundle of titanium oxide tubes, which changes its curvature corresponding to the relative humidity. The mechanism of changing the curvature of the film can be explained by adsorption, condensation, and evaporation of water molecules within the film. During adsorption, a liquid bridge is formed because of the growth of a water layer between tubes, thus contracting the tubes. When vapor pressure exceeds the equilibrium vapor pressure, condensation occurs at the meniscus of the liquid bridge, thus expanding the gap between tubes. We obtained the adsorption and desorption isotherms for the humidity responsive film by determining physical adsorption. Additionally, we demonstrated the varying motions of the humidity sensing film when a water droplet was applied on the surface. The sensor could distinguish between saturated and oversaturated humidity conditions, such as fog and rain, respectively, which is not possible using resistive humidity sensors. This humidity responsive film can be applied to environmental monitoring systems and possibly even to energy harvesting systems. [ABSTRACT FROM AUTHOR]

Rapid fabrication of anodic titanium oxide nanotubes is limited to its growth mechanism, because the growth mechanism is still dominated by the dissolution reaction of fluoride ions. Here, the growth rates of the nanotubes anodized at 50 V in four electrolytes of NH 4 F (0.2, 0.3, 0.4 and 0.5 wt%) increased slowly with the increasing concentration of NH 4 F. This phenomenon seems to be consistent with the dissolution reaction of fluoride ions. However, when titanium was anodized at the critical breakdown voltages, the growth rates of nanotubes obtained in 0.2, 0.3, 0.4 and 0.5 wt% NH 4 F electrolytes were 2.191, 0.869, 0.538 and 0.497 μm min−1, respectively. Therefore, the growth rates of nanotubes decreased with the increasing concentration of NH 4 F. Compared with the growth rate (0.140 μm min−1) under non-breakdown conditions (50 V), the growth rate (2.191 μm min−1) of nanotubes under the critical breakdown voltage was greatly increased. Obviously, the phenomenon of rapid growth of nanotubes in low concentration of NH 4 F electrolyte is contrary evidence of the dissolution reaction of fluoride ions and the dissolution equilibrium theory. • Rapid growth rate of anodic TiO 2 nanotubes can reach 2.19 μm min−1. • Equilibrium state appears in the process of anodization at low voltage. • Non-equilibrium state appears in anodization at critical breakdown voltage. • Growth rate is related to anodizing current rather than NH 4 F concentration. • Evidences against dissolution reaction of fluoride ion and equilibrium are proposed. [ABSTRACT FROM AUTHOR]

Abstract The aim of this paper was to present a parallel investigation of the poly(dopamine) (DP) and nitrodopamine (NDP) structures deposited on titanium surface (Ti) and titanium oxide nanotubes (NT-TiO 2 /Ti) and to highlight their advantages and drawbacks to serve as an intermediary layer for bone regeneration applications. This study outlines some hypotheses regarding the manner in which these compounds are able to form a stable film that could serve as bioadhesive. The paper is also a study of structuring and evolution of film architecture for two coatings, polydopamine and nitrodopamine in terms of surface structure, stability, wettability, morphology, adhesion and ability to protect the titanium surface. All investigations are based on the data provided by surface characterization techniques: SEM, RAMAN, XRD, XPS, wettability and flexural strength. The impact of polydopamine and nitrodopamine coatings on the biocompatibility of titanium nanotubes was investigated in vitro. Cell morphology, viability, proliferation and pre-osteoblast differentiation were examined in detail. It was highlighted that both DP and NDP functionalized TiO 2 nanotubes display good cell response in terms of cell spreading, formation of focal adhesions, cell viability and proliferation, suggesting their suitability for applications in bone regeneration field. However, NDP coated TiO 2 nanotubes demonstrated an enhanced osteogenic potential compared to DP coated substrates. Highlights • TiO 2 nanotubes were suitable for uniform depositions of polydopamine and nitrodopamine. • None of the deposits obstructed the nanotubes. • The better adhesive properties were obtained for polydopamine films. • The stability in time of nitrodopamine was superior to polydopamine. • NDP demonstrated an enhanced osteogenic potential compared to DP. [ABSTRACT FROM AUTHOR]

• Model to predict the average outer diameter of TONTs was linear. • Most relevant measurements in the modeling stage were Δ , I and θ = 75 °. • SVM achieved a very low prediction error of the average outer diameter. • Correlation coefficient R between real and predicted measurements was 0.99992. Nowadays, the development of new technology is strongly based on nanomaterials studies, such as vertically aligned TiO 2 nanotubes (TONTs), which are widely used in different fields of industry. Physical properties of these materials depend on their size (inner and outer diameters) and shape, for this reason they must be measured accurately. Inner and outer diameter measurement is performed manually on images obtained by means of scanning electron microscopy. Time-consuming image analysis, subjective and low-representative readings are some disadvantages found in this process. This paper proposes a model to predict the average outer diameter of TONTs using Data Mining and Ellipsometry, because they have the potential to overcome disadvantages mentioned above. The diameter with measurements of light reflection intensity and ellipsometric parameters is modelled using different techniques. A model that shows a very low prediction error using linear support vector machines for regression is reported. [ABSTRACT FROM AUTHOR]

A novel catalyst, TiO2 nanotubes ( TiO2 NTs) composite decorated by CuO and CeO2 particles, was prepared by a simple and cost-effective method. The TiO2 NTs were fabricated by the hydrothermal method, and CuO and CeO2 particles loaded onto TiO2 NTs (CuO/CeO2 @ TiO2 NTs) were prepared by the water bath heating method. The CuO/CeO2 @ TiO2 NTs were investigated and characterized by transmission electron microscope ( TEM), energy dispersive spectrometer ( EDS), photoluminescence (PL), X-ray diffractometer ( XRD) and ultraviolet-visible light diifuse reflectance spectrum (UV-Vis DRS). Both the p-n heterojunction formed at the p-CuO and n-TiO2 interfaces and the highly induced electron transfer of CeO2 can greatly promote the separation of elections-holes. Therefore, CuO/CeO2 @ TiO2 NTs show enhanced absorption and have potential applications in photocatalysis. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Recovery of Alexandrium tamarense was shown after chronic exposure to n TiO 2. • n TiO 2 aggregation and algal defense might contribute to the recovery. • PSTs content and toxicity increased upon chronic n TiO 2 exposure. • Highly-toxic analogue proportions of PSTs increased. • Ecological risks of A. tamarense might be enhanced upon chronic n TiO 2 exposure. Abstract Harmful algal blooms (HAB), heavily influenced by human activities, pose serious hazard to aquatic ecology and human health. In this study, we monitored the physiological responses and paralytic shellfish poisoning toxins (PSTs) of the toxin-producing HAB species Alexandrium tamarense under titanium dioxide nanoparticles (n TiO 2) exposure in the concentration range of 2–320 mg L−1 over a period of 13 days. The results showed the acute inhibition of n TiO 2 on the algal growth, photosynthetic efficiency and esterase activity at all concentrations except 2 mg L−1. Nonetheless, they recovered after 13 days n TiO 2 exposure from 20 to 80 mg L−1. The EC 50 value increased from 85.1 mg L−1 in Day 4 to 140.9 mg L−1 in Day 13. The physiological recovery after prolonged exposure may result from the elimination of excess reactive oxygen species (ROS), a combined outcome of increased n TiO 2 aggregation and algal antioxidant defense mechanisms. This observation is supported by the immediately increased antioxidant enzyme activities, including the superoxide dismutase (SOD) and catalase (CAT) activities upon n TiO 2 exposure. Moreover, the production of PSTs in A. tamarense significantly increased by 1.41–1.76 folds after chronic n TiO 2 exposure at all tested concentrations (p < 0.05), which might also be an adaptive response for the microalgae to overcome the stresses. In particular, the proportions of highly-toxic PSTs analogues GTX2/3, STX and dcSTX were significantly increased upon n TiO 2 exposure (p < 0.05). Hence, the chronic n TiO 2 exposure might aggravate the ecological impact of HABs. Furthermore investigations on different HAB species, especially those toxin-producing ones, and detail physiological responses are obviously needed. [ABSTRACT FROM AUTHOR]