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Experiments on specimen cooling dynamics and possible film boiling around a body are very important in various industrial applications, such as nucleate boiling, to decrease drag reduction or achieve better surface properties in coating technologies. The objective of this study was to investigate the interaction between the heat transfer processes and cooling dynamics of a sample in different boundary conditions. This article presents new experimental data on specimens coated with Al–TiO2 film and Leidenfrost phenomenon (LP) formation on the film's surface. Furthermore, this manuscript presents numerical heat and mass transfer parameter results. The comparative analysis of new experiments on Al–TiO2 film specimens and other coatings such as polished aluminium, Al–MgO, Al–MgH2 and Al–TiH2 provides further detail on oxide and hydride materials. In the experimental cooling dynamics experiments, specimens were heated up to 450 °C, while the sub-cooling water temperatures were 14*‒20 °C (room temperature), 40 °C and 60 °C. The specimens' cooling dynamics were calculated by applying Newton's cooling law, and heat transfer was estimated by calculating the heat flux q transferred from the specimens' surface and the Bi parameter. The metadata results from the performed experiments were used to numerically model the cooling dynamics curves for different material specimens. Approximated polynomial equations are proposed for the polished aluminium, Al–TiO2, Al–MgO, Al–MgH2 and Al–TiH2 materials. The provided comparative analysis makes it possible to see the differences between oxides and hydrides and to choose materials for practical application in the industrial sector. The presented results could also be used in software packages to model heat transfer processes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Titanium oxide (TiO2) coated polyimide has broad application prospects under extreme conditions. In order to obtain a high-quality ultra-thin TiO2 coating on polyimide by atomic layer deposition (ALD), the polyimide was activated by in situ oxygen plasma. It was found that a large number of polar oxygen functional groups, such as carboxyl, were generated on the surface of the activated polyimide, which can significantly promote the preparation of TiO2 coating by ALD. The nucleation and growth of TiO2 were studied by x-ray photoelectron spectroscopy monitoring and scanning electron microscopy observation. On the polyimide activated by oxygen plasma, the size of TiO2 nuclei decreased and the quantity of TiO2 nuclei increased, resulting in the growth of a highly uniform and dense TiO2 coating. This coating exhibited excellent resistance to atomic oxygen. When exposed to 3.5 × 1021 atom cm−2 atomic oxygen flux, the erosion yield of the polyimide coated with 100 ALD cycles of TiO2 was as low as 3.0 × 10−25 cm3/atom, which is one order less than that of the standard POLYIMIDE-ref Kapton® film. [ABSTRACT FROM AUTHOR]

Background: Infective endocarditis (IE) poses a significant health risk, especially in patients with prosthetic heart valves. Despite advances in treatment, mortality rates remain high. This study aims to investigate the antibacterial properties of a copper titanium dioxide (4× Cu‐TiO2) coating on cardiovascular implants against Staphylococcus aureus, a common causative agent of IE. Methods: Titanium oxide carriers functionalized with copper ions were employed as an antibacterial coating for heart and vascular prostheses. The coating's antibacterial efficacy was assessed using S. aureus ATCC 29213. Microscopic evaluations were conducted on both biological and artificial materials. Antibacterial activity was qualitatively assessed via a modified disc diffusion method and quantitatively measured through colony counts in NaCl suspensions. Results: The coating process was successfully applied to all tested cardiovascular prosthetic materials. Qualitative assessments of antibacterial effectiveness revealed an absence of bacterial growth in the area directly beneath the coated valve. Quantitative evaluations showed a significant reduction in bacterial colonization on coated mechanical valves, with 2.95 × 104 CFU per valve, compared to 1.91 × 105 CFU in control valves. Conclusions: The 4× Cu‐TiO2 coating demonstrated promising antibacterial properties against S. aureus, suggesting its potential as an effective strategy for reducing the risk of bacterial colonization of cardiovascular implants. Further studies are needed to assess the longevity of the coating and its efficacy against other pathogens. [ABSTRACT FROM AUTHOR]

TiO2 and TiO2–SiO2 composite coatings were electrophoretically deposited on anodized 316L stainless steel substrates and then sintered at 1100 °C. TiO2 coating showed a rutile phase composition involving a cracked surface with a wide diffusion region rich in chromium element near the substrate. While TiO2–SiO2 composite coating showed a crack-free surface with an anatase phase comprising a continuous interlayer. Formation of the dense interlayer prevented the diffusion of substrate elements toward the coating during the sintering and thus inhibited the formation of diffusion region. According to the EIS study after 1 day of immersion in PBS solution, the highest barrier performance belonged to TiO2–SiO2 composite coating where its total faradic resistance (84 MΩ cm2) was 1500 times higher than TiO2 coating and 5.6 times higher than the anodized substrate. This was related to the crack-free surface and the interlayer formed in the composite coating owing to the improving effects of silica. After 28 days of immersion, the total faradic resistance of the TiO2–SiO2 composite coating remained significantly higher (order of 106–107 Ω cm2) than TiO2 coating (∼104 Ω cm2). Furthermore, TiO2–SiO2 composite coating enhanced the apatite formation compared to TiO2 coating or anodized substrate during immersion in SBF solution.

Lithium-sulfur batteries (Li-S) are highly promising due to their high energy density and specific capacity; however, the poor conductivity of the active material leads to slow reaction kinetics, and the shuttle effect of the intermediate product lithium polysulfides leads to rapid capacity decay. Here, the effective encapsulation of Al-BDC by TiO2 particles is achieved by encapsulating an aluminum-based metal organic framework (Al-BDC) with terephthalic acid as the organic ligand and heat-treating at different temperatures. This method shows that the TiO2 particles can effectively encapsulate Al-BDC while maintaining the structural stability of Al-BDC after heat treatment at 400°C. The TiO2 crystallization is disordered after heat treatment at 300°C, and the TiO2 is exfoliated and the Al-BDC is collapsed after heat treatment at 500°C. In addition, TiO2 particles can be partially filled into the pores of Al-BDC. Therefore, Al-BDC@TiO2-400 can effectively inhibit the shuttle of polysulfides, and the corresponding Li-S batteries can achieve relatively high discharge specific capacity, rate performance and cycling stability. In particular, the Al-BDC@TiO2-400@S can achieve an initial discharge specific capacity of 907.6 mAh g−1 at 0.1C, and 686.5 mAh g−1 at 2C with remained capacity of 379.8 mAh g−1 after 400 cycles. [ABSTRACT FROM AUTHOR]

To enhance the mechanical properties of carbon fiber (CF) reinforced 7075 Al alloy material at high temperature conditions, TiO2 coating was prepared on the surface of CF by chemical vapor deposition. The composites were prepared by hot pressing sintering and hot extrusion methods. The evolution of the compositional components of the composite interface was investigated. The density, hardness, and tensile strength of the samples were measured, and the strength/density ratio of the samples was calculated at 150 °C. The results indicate that the tensile strength of coated CF reinforced composite (535 MPa) was increased by 21.3% and 5.7% compared to the tensile strength of 7075 Al alloy (441 MPa) and uncoated CF reinforced composite (506 MPa), respectively. Furthermore, the strength/density ratio of the composite also increased with the addition of TiO2 coating. The enhancement of coating on CF on tensile strength is attributed to the transformation of CF failure mode.

Electrolytic water splitting is a promising path for the production of clean hydrogen when combined with green electric power, such as photovoltaic and wind power; however, the high current water electrolysis is mainly dependent on the utilization of Pt, Ru, and other expensive materials, while the transition metal-based catalysts still need improvement in electrocatalytic activity and stability. Here, we present the preparation of economic and scalable electrode materials, Nickel-Iron phosphide/Nickel foam (NiFeP/NF), with a hierarchical porous structure for overall water splitting as both the anode and cathode. An overall potential of 1.85 V for the current density of 100 mA cm−2, and a long lifetime of 700 h, were achieved by using NiFeP/NF as both the anode and cathode. The nanostructures of the composite phosphides were investigated and the spent electrode after long-term electrolysis was characterized to investigate the long-term failure mechanism of the phosphides. Surface shedding and reconstruction theories were proposed for the failure of the NiFeP/NF cathode and anode in long-term electrolysis, respectively. Furthermore, TiO2 coating was proved to be an efficient strategy to elongate the lifetime of the phosphide electrodes, which shows a slow current decline rate of 0.49 mA·cm−2 h−1. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this research work, pool-boiling heat transfer is conducted with the consideration of T i O 2 hydrophilic nanoparticles as coating material using Electrospray Deposition (ESD) method. The study focused on the impact of spray parameters such as injection flow rate, solution concentration, and spray time on the formation of the coating structure, porosity, cavity characteristics, and thickness. Moreover, X-ray diffraction (XRD), Energy Dispersive X-ray spectroscopy (EDX), Profilometric Analysis, and Scanning Electronic Microscopy (SEM) images were utilized to analyze the surfaces. As a result, pool boiling was ameliorated by reaching the effective cavity size, rewetting the surface, and improving the bubble departure mechanism. Furthermore, the coating's stability and adhesion were examined in the boiling results, due to the existence of a small decrease in the curves. The optimal case increased the Maximum Heat Flux (MHF) and maximum Heat Transfer Coefficient (HTC) up to 90% and 118.3%, respectively. In addition, reduced the superheat temperature to 31.7% relative to the plain copper surface. [ABSTRACT FROM AUTHOR]

Lacking osseointegration and peri-implantitis induced by bacterial infiltration are the pivotal issues for the long-term clinical success of implants. In order to improve the bioactivity and antibacterial properties of implant materials, volcano-shaped microporous TiO2 coatings doped with Zinc (Zn) were fabricated via a micro-arc oxidation (MAO) method on pure titanium (Ti). The microstructure, morphology, and chemical composition of the Zn-doped coatings were systematically studied. In cell culture tests, the formed coatings promoted the adhesion and proliferation of bone mesenchymal stem cells (BMSCs), exhibiting good biocompatibility. The antibacterial experiments revealed that Zn-TiO2 coatings possess excellent antibacterial properties against Staphylococcus aureus (S. aureus) and Porphyromonas gingivalis (P. gingivalis). [ABSTRACT FROM AUTHOR]

In order to enhance osteogenic differentiation and antibacterial property of dental implants, volcano-shaped microporous TiO2 coatings doped with Cu were fabricated via micro-arc oxidation (MAO) on Ti. Cu-doped coating with different mass ratios of Cu were obtained by changing the concentration of copper acetate in the electrolyte. The structure of Cu-TiO2 coatings were systematically investigated. Element Copper was uniformly distributed throughout the coating. Compared with TiO2 coating, the Cu-doped can further improved proliferation of bone mesenchymal stem cells (BMSCs), facilitated osteogenic differentiation. The bacteriostasis experiments demonstrated that Cu-doped TiO2 coating possess excellent antibacterial property against Staphylococcus aureus (S. aureus) and Porphyromonas gingivalis (P. gingivalis).

Zirconia is a superior implant material owing to its high mechanical strength, durable corrosion resistance, superior aesthetic effect and excellent biocompatibility. However, the bioactivity of zirconia surfaces remains a great challenge for implant osseointegration. A titania (TiO2) coating was innovatively synthesized on the surface of zirconia by infiltration in a suspension of zirconium oxychloride and titania for dense sintering. Subsequently, the coating was subjected to ultraviolet (UV) light to enhance the biological inertness of zirconia. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and contact angle analysis were conducted to confirm the surface characteristics. Afterwards, in vitro assessments of cell adhesion, proliferation and osteogenic differentiation of MC3T3-E1 cells were performed. Zirconia samples were implanted into rat femurs to assess biocompatibility and host tissue response in vivo. Micro-CT evaluation and histological testing were conducted. After UV irradiation, the content of hydroxyl groups and hydrophilicity of TiO2-modified zirconia were significantly increased. The results of in vitro experiments showed that TiO2-modified zirconia subjected to UV light could promote cell proliferation and spreading, enhance ALP activity and the degree of mineralization, and upregulate osteogenesis-related genes. Furthermore, in vivo assessments confirmed that UV-irradiated TiO2-modified zirconia implants maximized the promotion of osseointegration. TiO2-modified zirconia after UV treatment will have broad clinical application prospects in improving the osseointegration of zirconia implants.

• TiO 2 -coated glass hollow fiber membrane is prepared via dip-coating process. • Photocatalytic process is applied to improve methylene blue removal degree. • Methylene blue removal rate reaches 98% within 8 h photocatalytic reaction. • The membrane with the removal degree of 92.3–93.6% exhibits long-term stability. A glass hollow fiber membrane coated with TiO 2 was successfully synthesized by dip-coating and calcination. In addition, the effects of the calcination temperature, number of coating layers, and treatment method on the photocatalytic removal of methylene blue from wastewater by the membrane were investigated. The results showed that the TiO 2 -coated membrane calcined at 550 °C was uniform. It showed good photocatalytic and anti-fouling properties. As compared to the basement membrane, the TiO 2 -coated membrane showed significantly improved photocatalytic removal of methylene blue. It showed a methylene blue removal degree as high as 97.2% and could be recycled multiple times by a simple treatment. The methylene blue removal degree of the membrane remained 92.3-93.6% after five recycling operations. Therefore, the membrane prepared via the simple method proposed in this study could be used as an efficient photocatalyst to remove methylene blue from wastewater. [ABSTRACT FROM AUTHOR]

Austenitic stainless steels are commonly used as the base material for dry storage canisters in nuclear power plants because of their excellent corrosion resistance and mechanical properties. Dry storage canisters are often exposed to chloride-containing atmosphere near seashores that could induce localized stress corrosion cracking in these stainless steels near the welded regions. Titanium dioxide (TiO2) coatings applied on stainless steel substrates (i.e. Type 304 L stainless steels) along with ultraviolet irradiation have been proposed as a mitigation measure against corrosion in canister materials. In this study, TiO2 coatings were applied on stainless steel samples using a dip-coating method. The coated samples were then thermally treated under different annealing temperatures. Corrosion behavior and photocatalytic responses of the coated samples with and without UV illumination were evaluated by electrochemical polarization analyses and open circuit potential measurements. Surface morphologies of the samples and the crystal structures were studied by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). It was found that the TiO2 coating not only showed markedly enhanced photocathodic protection on Type 304 L stainless steels during UV illumination but also maintain more active open circuit potentials for several hours after the cutoff of UV illumination. Results from electrochemical polarization analyses further supported the superior corrosion resistance of the coated samples under UV illumination conditions. In addition, the specifically processed TiO2 coatings once irradiated with UV could lead to a prolonged corrosion resistance of the samples even hours without UV illumination.

In this study, unidirectional flax fabrics were used to reinforce poly(lactic acid) (PLA). Flax/PLA composites were produced by thermo-compression using as-received flax fibers and titanium dioxide (TiO2) coated flax fibers. The aim was to investigate the effect of annealing temperature and time, under quiescent or mechanical stress conditions, on the microstructure, interfacial adhesion, crystallization, and mechanical properties of composites. Results showed significant differences between oxidized-TiO2-coated flax fibers/PLA composites (oxi-TiO2-C) and as-received flax fibers/PLA composites (AR-C). Indeed, above the glass transition temperature (Tg) of PLA, the storage modulus (E') of both composites significantly increased due to PLA crystallization. However, once E' reached a maximum value, composites with treated flax fibers leveled off while the E' of composites with untreated flax fibers dropped drastically. This peculiar result was explained by a partial destruction or damage of AR-C interface during PLA crystal growth. This phenomenon was not observed with oxi-TiO2-C, suggesting a good interfacial adhesion. Despite the presence of a trans-crystalline layer for both samples, it was shown that TiO2 coating of flax fibers strengthened the adhesion between flax fibers and the trans-crystalline structure. Interlaminar shear strength measurements revealed a 15% increase in the interfacial strength. [ABSTRACT FROM AUTHOR]

The present study proposes a protective TiO2 coating against chloride driven stress corrosion cracking problem of 316L austenitic stainless steel. To test the performance of the proposed coating, the severe chloride-based boiling magnesium chloride solution at 155 °C was chosen. For experimentation, the constant strain-based U-bend specimens were coated with TiO2 using atmospheric plasma spray method. The results indicated higher resistance by TiO2 coated specimens against stress corrosion cracking problem, while the bare specimens experienced severe damage in the boiling magnesium chloride solution under various strain loading configurations. The coating-electrolyte system of TiO2 coated sample demonstrated over seven times higher resistance, eventually led to reduction in corrosion rate over fifteen times compared to the bare 316L stainless steel in the boiling magnesium chloride solution. This improved performance of the coated 316L stainless steel is attributed to inhibition of outward diffusion of iron-chromium-nickel in the corrosive environment and the high chemical stability of TiO2. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Titanium dioxide (TiO 2) coatings are demanded in clinical applications due to their biocompatible, porosity, and semiconducting properties. Drug release studies take advantage of these unique aspects of TiO 2 for painless injection for those who have to take medicine through the injection frequently. In this study, TiO 2 was prepared via the sol-gel method with Titanium tetra isopropoxide (TTIP) precursor in alcohol solvent for pH 3, 4, and 5 values. The prepared solution was coated on stainless steel substrates and injectors via dip coating. Following these steps, samples were calcinated at various temperatures (100°C, 300°C, 500°C, 700°C). The structural, physical, and chemical composition, chemical bond, wettability, and drug-release properties of coated samples were researched. Contact angle values affirmed that high temperatures and ultraviolet (UV)-light irradiation made samples more hydrophilic (26°±5° at 700°C for pH 4). Procaine, a short-time period local anaesthetic, was chosen as a model drug. Increased calcination temperature and raised hydrophilicity led to improve the released drug amount. Drug release studies were carried out using Franz diffusion cells at 36.5°C. Samples at 500°C calcinated released the highest amount of drug (90%) for 45 sec injection time. This study shed light on how TiO 2 coating can be successfully utilized for clinical applications in the future. [Display omitted] • TiO 2 -coated injectors showed the anatase phase, and crystallinity was seen clearly at 500 °C and 700 °C. • After the UV-light hydrophilicity increased, the most hydrophilic surface was observed at 700 °C after UV-light exposure. • SEM results showed as the calcination temperature increases, pore formation on the surface occurs. • Samples calcinated at 300 °C and 500 °C released 52% and 90% amount of the drug, respectively. [ABSTRACT FROM AUTHOR]

Antifouling surfaces have been widely studied for their importance in medical devices and industry. Antifouling surfaces mostly achieved by methoxy-poly(ethylene glycol) (mPEG) have shown biomolecular adsorption less than 1 ng/cm(2) which was measured by surface analytical tools such as surface plasmon resonance (SPR) spectroscopy, quartz crystal microbalance (QCM), or optical waveguide lightmode (OWL) spectroscopy. Herein, we utilize a single-molecule imaging technique (i.e., an ultimate resolution) to study antifouling properties of functionalized surfaces. We found that about 600 immunoglobulin G (IgG) molecules are adsorbed. This result corresponds to ∼5 pg/cm(2) adsorption, which is far below amount for the detection limit of the conventional tools. Furthermore, we developed a new antifouling platform that exhibits improved antifouling performance that shows only 78 IgG molecules adsorbed (∼0.5 pg/cm(2)). The antifouling platform consists of forming 1 nm TiO2 thin layer, on which peptidomimetic antifouling polymer (PMAP) is robustly anchored. The unprecedented antifouling performance can potentially revolutionize a variety of research fields such as single-molecule imaging, medical devices, biosensors, and others.

Herein, the electrorheological (ER) performances of ER fluids were correlated with their colors to allow for the visual selection of the appropriate fluid for a specific application using naked eyes. A series of TiO2-coated synthetic mica materials colored white, yellow, red, violet, blue, and green (referred to as color mica/TiO2 materials) were fabricated via a facile sol–gel method. The colors were controlled by varying the thickness of the TiO2 coating layer, as the coatings with different thicknesses exhibited different light interference effects. The synthesized color mica/TiO2 materials were mixed with silicone oil to prepare colored ER fluids. The ER performances of the fluids decreased with increasing thickness of the TiO2 layer in the order of white, yellow, red, violet, blue, and green materials. The ER performance of differently colored ER fluids was also affected by the electrical conductivity, dispersion stability, and concentrations of Na+ and Ca2+ ions. This pioneering study may provide a practical strategy for developing new ER fluid systems in future.

In this paper, the sol-gel method was used first to obtain the layered cathode material Li1.2Mn0.54Ni0.13Co0.13O2, and then the nanoparticles of TiO2 were coated samples in via a wet chemical process. Finally, a systematic study of the different amounts of TiO2 materials coated was carried out. XRD and SEM analysis showed that these materials after TiO2 coating have a good layered structure and regular morphology, respectively. Experiments such as XPS and TEM showed that the TiO2 nanoparticles were evenly distributed on the surface of the particles, and no substantial changes were made to each transition metal elements. Through electrochemical testing, when the TiO2 coating amount is equal to 1.0%, the first discharge-specific capacity reaches 276.5 mAh/g at 0.1 C, and the Coulomb efficiency is also as high as 80.8%. Compared with the uncoated sample, when the coating amount is 1.0%, the TiO2 coating suppresses the lack of surface oxygen and makes the structure more stable. The electrochemical performance of the material has been significantly improved. [ABSTRACT FROM AUTHOR]

Background: Infective endocarditis (IE) poses a significant health risk, especially in patients with prosthetic heart valves. Despite advances in treatment, mortality rates remain high. This study aims to investigate the antibacterial properties of a copper titanium dioxide (4× Cu-TiO 2 ) coating on cardiovascular implants against Staphylococcus aureus, a common causative agent of IE., Methods: Titanium oxide carriers functionalized with copper ions were employed as an antibacterial coating for heart and vascular prostheses. The coating's antibacterial efficacy was assessed using S. aureus ATCC 29213. Microscopic evaluations were conducted on both biological and artificial materials. Antibacterial activity was qualitatively assessed via a modified disc diffusion method and quantitatively measured through colony counts in NaCl suspensions., Results: The coating process was successfully applied to all tested cardiovascular prosthetic materials. Qualitative assessments of antibacterial effectiveness revealed an absence of bacterial growth in the area directly beneath the coated valve. Quantitative evaluations showed a significant reduction in bacterial colonization on coated mechanical valves, with 2.95 × 10 4 CFU per valve, compared to 1.91 × 10 5 CFU in control valves., Conclusions: The 4× Cu-TiO 2 coating demonstrated promising antibacterial properties against S. aureus, suggesting its potential as an effective strategy for reducing the risk of bacterial colonization of cardiovascular implants. Further studies are needed to assess the longevity of the coating and its efficacy against other pathogens., (© 2023 The Authors. Artificial Organs published by International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

To improve the bioactivity and antibacterial properties of implant materials. In this study, the biomedical titanium alloy (Ti-6Al-4V) was covered by yttrium doped titanium dioxide (Y-TiO2) coating via a plasma electrolytic oxidation (PEO) method. By changing the concentration of yttrium acetate in the electrolyte, Y-TiO2 coating with different mass ratios of yttrium were obtained. The structure morphology and chemical composition of the Y-TiO2 coating were systematically characterized. The results indicated that the porous and micro-nanostructured Y-TiO2 coatings were constructed by the pores smaller than 4 μm. Definitely yttrium was not only distributed on the surface but also embedded in the coating. Yttrium mainly existed in form of Y2O3 and Y3+ state in prepared TiO2 coating. Element release profiles confirmed that yttrium release slowly from Y-TiO2 for 32 days. Cell culture tests demonstrated that Y-TiO2 coating exhibited good biocompatibility on osteoblastic precursor cells and fibroblasts cells with increasing doping concentration of yttrium. Bacteriostasis experiments revealed that Y-TiO2 coating possess excellent antibacterial property against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Thus, the prepared Y-TiO2 coating with outstanding biocompatibility and antibacterial capacity provided a preferred strategy for the repair and reconstruction of bone tissues in dentistry and orthopedics.

The effects of the process conditions (withdrawal rate and coating repetition) on the morphological characteristics of sol–gel TiO2 film during dip coating were studied. We carried out dip-coating experiments to observe the effect of the withdrawal rate, coating repetition, and heat treatment on morphological development (homogeneity, thickness, and defects) in coated film. Sol was prepared with acetic acid catalyst and ethyl acetoacetate chelating agent. Withdrawal rate varied between 0.4 and 3.2 mm/s. Multilayered coatings were prepared by conducting 1, 2, 3, 5, and 10 cycles of coating. Heat treatment was carried out for 30 min at 450°C in air. The properties of the TiO2 film were characterized by visual observation, SEM, FIB, FTIR, and electrochemical impedance spectroscopy (EIS). As the withdrawal rate increased, the homogeneity of the film decreased, while the thickness of the film increased to a certain limit without cracking. A homogeneous coating, without edge effect, formed at an intermediate withdrawal rate of 0.1–1 mm/s, conditions under which both viscous drag and capillarity feeding were active. As the number of coatings increased, the coating thickness increased and cracking increased. EIS tests were used to analyze internal defects in coatings. With repeated coating, defects in coatings increased. After a 30-min heat treatment at 450°C in air, pore resistance (Rpore) decreased approximately 20–30% compared to Rpore of specimens without heat treatment. This study confirmed that it is important to control the morphology to obtain optimum properties of TiO2 film as a coating for corrosion barriers, photocatalysts, and photoelectric and optical applications. [ABSTRACT FROM AUTHOR]

Group III–V compound semiconductors are a promising group of materials for photoelectrochemical (PEC) applications. In this work, a metal assisted wet etching approach is adapted to acquiring a large‐area patterned microdome structure on p‐GaAs surface. In addition, atomic layer deposition is used to deposit a TiO2 protection layer with controlled thickness and crystallinity. Based on a PEC photocathode design, the optimal configuration achieves a photocurrent of −5 mA cm−2 under −0.8 V versus Ag/AgCl in a neutral pH electrolyte. The TiO2 coating with a particular degree of crystallization deposited via controlled temperature demonstrates a superior stability over amorphous coating, enabling a remarkably stable operation, for as long as 60 h. The enhanced charge separation induced by favorable band alignment between GaAs and TiO2 contributes simultaneously to the elevated solar conversion efficiency. This approach provides a promising solution to further development of group III–V compounds and other photoelectrodes with high efficiency and excellent durability for solar fuel generation. [ABSTRACT FROM AUTHOR]

This study was conducted to measure the inactivation characteristics of UVs and TiO2 against Salmonella. Typhimurium and Escherichia coli O157:H7 on black pepper powder. The sample was irradiated by UV-A and UV-C combined with TiO2 coating. After treatment, microbial and physicochemical analysis was carried out. Among various sterilization conditions, the largest number of pathogen in black pepper powder was inactivated by UV-A and UV-C combined with TiO2 coating. The microbial count of black pepper powder treated simultaneously with UV-A and UV-C was less than that of black pepper powder treated with alone. The inactivation effect of UV-A and UV-C was increased when TiO2 coating was combined. Moisture content was decreased with increasing treatment time, but color did not change. In this study, it was indicated that the combined treatment of UV-C, UV-A and TiO2 coating was effective for reducing S. Typhimurium and E. coli O157:H7 on black pepper powder. [ABSTRACT FROM AUTHOR]

[Display omitted] • TiO 2 acts as an electron additive to change the electronic state of the Pt. • Ti3+-Ptδ− site enables hydrogen heterolytic cleavage to produce protons. • Ti3+-Ptδ− sites change the reactant adsorption and bond cleavage energy barriers. • The mechanism of C-N bond breaking is first protonation and then β-elimination. • Four-fold increase in durability of deposited TiO 2 catalysts. C–N bond breaking is a difficult but crucial step in the quinoline removal of coal-based liquids. Noble metal catalysts have higher C–N bond breaking activity, but their surface bond breaking mechanism is unclear. Atomic layer deposition creates more metal-oxide sites and generates different active species, which facilitates the mechanism study. For this reason, we used atomic layer deposition to deposit TiO 2 on the catalyst surface and suggested a more complete C–N bond breaking mechanism in this study. The particle size and pore structure of the catalyst did not change significantly after the deposition, and the hydrogen adsorption was reduced when there were too many layers deposited and the surface Pt sites were occupied to a high degree. TiO 2 is extremely susceptible to reduction to Ti3+ under hydrogen, and can change the nature of the electron density of Pt through oxygen vacancies, creating Ti3+-Ptδ− sites that are prone to protonation reactions. That means, the occurrence of these protonation reactions not only easily breaks the C–N bond, but also accelerates the rate of C–N bond cleavage due to the increased H coverage on the surface of the xcTi-PtAl catalysts. And the Ti3+-Ptδ− sites in catalyst had a stronger adsorption effect on the nitrogen-containing compounds, which in turn lowered the energy barriers of bond cleavage. It is concluded that protonation is a necessary step before the C–N bond can be broken. The subsequent steps were showed by the DFT calculations that the nitrogen-containing compounds adsorbed on the Ti3+-Ptδ− sites undergo β-H fracture after the protonation reaction, with the elimination reaction cleaving the C–N bond. The xcTi-PtAl catalysts by atomic layer deposition of Ti not only improve the C–N bond breaking performance, but also improve bond breaking stability by a factor of four compared to the Pt/Al 2 O 3 catalysts. [ABSTRACT FROM AUTHOR]

The surface texture of a stone represents a sensitive parameter in evaluating its conservation state. In monuments and sculptures, in fact, external agents continuously alter the appearance of stones, determining peculiar weathering patterns and modifying properties such as retention of water and particles, interaction with light, color, and finishing. The application of protective coatings also determines changes in surface appearance of a stone, usually evaluated and monitored by color change tests. Surface metrology methods offer the possibility to quantify these changes, evaluating the impact of external agents (natural, i.e. weathering, and artificially, i.e. protective coatings) on natural stones. In this research, we demonstrate the potential of surface areal measurements in describing the evolution of weathering processes and the effects of protective treatments on porous stone materials. The obtained results suggest that the extent of the modifications is related to the scale of observation (small- vs. large-scale undulations, i.e. roughness and waviness, respectively), with an overall increase of surface roughness as the weathering proceeds. Unexpectedly, coatings based on nanoparticle dispersions increase the topographic height parameters, due to the absence of a homogeneous film. [ABSTRACT FROM AUTHOR]

In the present study, the hard TiO 2 coating was plasma sprayed on the Al/SiC composite substrate. The coating was characterised for microstructure, mechanical and tribological properties and compared with the substrate. The key findings from the present study are: (1) The lamellae structure of the coating contains semi and fully melted particles, round porosity without any evidence of spallation or delamination or un-melted particles and non-stoichiometric and oxygen deficient phases and shorter stand-off distance would be a probable reason for the occurrence of partial melted regions and porosity in the coating, (2) The coating has improved significantly scratch resistance, hardness, fracture roughness, friction coefficient and wear resistance of the substrate, and (3) mild abrasive wear is responsible for low wear loss in the coated sample whereas the combination of severe delamination wear and abrasive wear causes the considerable wear loss in the uncoated sample. [ABSTRACT FROM AUTHOR]

Abstract Microwave diathermy treatment has been successfully applied to such patients as for it can induce clinical hyperthermia to healing muscle skeletal injuries. However, as a contraindication, patients implanted with metallic implants for internal fixation of bone fracture could not take the microwave diathermy treatment. This is mainly due to microwave induced sudden temperature rise in metal implants, which will lead to heat damages in local tissues. The aim of this study is to improve the heat-resisting effect of titanium implants by modifying its surface. A uniform TiO 2 coating has been designed and fabricated on the surface of Ti (TA3) substrate by the method of anodic oxidation to inhibit the excessive heat generation of metallic implants. In vitro microwave irradiation experiment, the temperature of Ti substrate increased 2.5 °C, TiO 2 coated substrate increased only 1.4 °C, decreasing almost 50% under the same testing condition. The results indicate that the anodized TiO 2 coating may be an effective method to reducing the temperature rise of the metal implants during microwave diathermy treatment, which will provide a potential rehabilitation solution to internal fixation of bone fracture. Highlights • Microwave diathermy treatment has been applied to such patients as for it can induce clinical hyperthermia to healing muscle skeletal injuries. • Patients implanted with metal orthopedic implants are not allowed to take microwave diathermy treatment due to the hyperthermal induced heat damages in local tissues. • The aim of the work is to use TiO 2 coating to reduce the hyperthermal induced temperature rise in metal implants under microwave diathermy treatment. • The results indicate that the anodized TiO 2 coating may be an effective method to reducing the temperature rise of the metal implants during microwave diathermy treatment. [ABSTRACT FROM AUTHOR]

Abstract Aluminum and aluminum alloys have been very useful in the industry, mainly in the transport sector. So, is important to improve their mechanical properties to increase their applications. Carbon nanotubes (CNTs) could be an excellent reinforcing phase for metal matrix composites, specifically for composites with aluminum or aluminum alloy matrix. However, CNTs dispersion, wettability, and interaction with the matrix must be improved, without damaging their structure. In this work, multi-walled CNTs (MWCNTs) were coated by the sol-gel process with a titanium oxide (TiO 2) layer with three different thickness and calcined at two different temperatures: 500 °C and 750 °C. The resultant powder was mixed by electrostatic adsorption method with aluminum powder and cold compacted. To simulate high temperature processing, the compacted disks were pressureless heated at 850 °C, aiming to check the effect of TiO 2 in protecting the MWCNT when in contact with melted Al. The TiO 2 coated MWCNT samples were characterized by a range of analytical techniques including Field-Emission Gun Scanning Electron Microscopy (FEG-SEM), X-ray diffraction (XRD), Z-Potential, Brunauer–Emmett–Teller (BET), Energy Dispersive X-Ray Spectroscopy (EDS) and Raman Spectroscopy (RS). The effect of the TiO 2 layer as a protective barrier on the MWCNT against the Al 4 C 3 formation during the heating process and the hardness of the Al/MWCNT (coated and uncoated) composite were studied. The results show that the MWCNT were successful coverage by a uniform amorphous TiO 2 layer. After calcination at 500 °C and 750 °C, the layer was completely crystallized into a TiO 2 film, with reduced surface area and pore volume. Electrostatic adsorption between TiO 2 covered MWCNT and Al powders in aqueous suspension was found to disperse the reinforcing phase prior to consolidation. On the heat-treated discs, the formation of Al 4 C 3 phase was observed to occur only for uncoated MWCNT samples, showing that the TiO 2 layer effectively protected the nanotubes in presence of melted Al. The microhardness of the heated samples was increased up to 26% when reinforced with MWCNT and up to 46% when reinforced with TiO 2 coated MWCNT, compared with pure aluminum. Highlights • A TiO 2 coating was successfully obtained over the MWCNT. • The influence of calcination temperature in the TiO 2 coating was characterized. • A mixed Al/TiO 2 /MWCNT powder was obtained by electrostatic attraction. • The effect of TiO 2 in protecting the MWCNT when in contact with melted Al is investigated. • The influence of the reinforcing phase dispersion in the composite performance is discussed. [ABSTRACT FROM AUTHOR]

Cotton fabrics have been used in a variety of applications due to its attractive properties of softness, comfort, warmth, biodegradability and breathability. Coating cotton fabrics with photocatalytic materials can extend their use as self-cleaning and other practical applications. In this study, coating of cotton fabrics with dye sensitized/TiO2 for self-cleaning and UV blocking properties has been reported. Phthalocyanine based reactive dye, Reactive Blue-25 (RB-25), has been used as a visible light scavenger for TiO2. RB-25/TiO2 hybrid sol was prepared by sol-gel method and coated on the cotton fabrics via dip-pad-dry-cure method. The coated cotton fabric was characterized by FTIR-ATR, UV-Visible absorption, XRD, SEM and reflectance measurements. The surface studies confirmed the stable attachment of RB-25/TiO2 on the cotton fabric while photocatalytic and UV absorption studies shown that the RB-25/TiO2 coated cotton fabric exhibit substantial visible light driven self-cleaning and UV blocking properties. Rhodamine B (RhB) dye was used as to examine the photocatalytic efficiency of the coated cotton fabric. 91% RhB was degraded in 180 min when exposed to visible light in the presence of RB-25/TiO2 coated cotton fabric. [ABSTRACT FROM AUTHOR]

In this study, the effects of gamma and electron radiation on reflectivity of silver mirrors coated by TiO2 and Ta2O5, in the wavelength range 250 to 1100 (nm) has been investigated. The coatings are considered for space applications in LEO orbit at 500 (km) from the earth surface for three-year mission in space. Electron and gamma dose absorbed within the three-year are respectively about 7.5 (KGy) and 0.4 (KGy) in this orbit. To measure the resistance of TiO2, gamma radiation with CO60 irradiation source was applied on the sample in the range from 0.2 to 20 (KGy) including dose 400 (Gy) at the desired height. At the highest dose, 20 (KGy), radiation effects on both samples were compared with each other. The atomic force microscopy was used to investigate the effect of radiation on the quality of samples surface after radiation, and an spectrophotometer was used to measure the samples reflection before and after radiation. The results showed that in spite of very minor surface changes, and color change of the mirror substrate, its reflection remains unchanged with TiO2 and Ta2O5 coatings.

Orthorhombic MoO 3 (α-MoO 3 ) with multivalent redox couple of Mo 6+ /Mo 4+ and layered structure is a promising cathode for rechargeable aqueous Zn-ion batteries (AZIBs). However, pure α-MoO 3 suffers rapid capacity decay due to the serious dissolution and structural collapse. Meanwhile, the growth of byproduct and dendrite on the anode also lead to the deterioration of cyclic stability. This article establishes the mechanism of proton intercalation into MoO 3 and proposes a joint strategy combining structural modification with electrolyte regulation to enhance the cyclic stability of MoO 3 without sacrificing the capacity. In ZnSO 4 electrolyte with Al 2 (SO 4 ) 3 additive, TiO 2 coated oxygen-deficient α-MoO 3 (MoO 3-x @TiO 2 ) delivers a reversible capacity of 93.2 mA h g -1 at 30 A g -1 after 5000 cycles. The TiO 2 coating together with the oxygen deficiency avoids structural damage while facilitating proton diffusion. Besides, the additive of Al 2 (SO 4 ) 3 , acting as a pump, continuously supplements protons through dynamic hydrolysis, avoiding the formation of Zn 4 SO 4 (OH) 6 ·xH 2 O byproducts at both MoO 3-x @TiO 2 and Zn anode. In addition, Al 2 (SO 4 ) 3 additive facilitates uniform deposition of Zn owing to the tip-blocking effect of Al 3+ ion. The study demonstrates that the joint strategy is beneficial for both cathode and anode, which may shed some light on the development of AZIBs., (© 2023 Wiley-VCH GmbH.)

The properties of cold-sprayed ceramic coatings depend not only on the process parameters but also on the feedstock powder characteristics. To clarify the effect of feedstock powder on cold spraying, two titanium oxide powders were used in this study: (1) nanopowder and (2) agglomerated powder prepared with nanoparticles and polyvinyl alcohol. The cross sections of the deposited coatings were observed by scanning electron microscopy (SEM). The results showed that the agglomerated powder with micrometer particles made of nano-sized particles passes successfully through the bow shock layer and reached the substrate, thus forming a coating. These particles are embedded into the substrate and form a strong interfacial coating/substrate bond. SEM images revealed that the metallic substrate undergoes plastic deformation, providing interlocking with the particles of the powder, and hence, reasonable bonding to the substrate. [ABSTRACT FROM AUTHOR]

Abstract A unique double core-shell structure of Si@PANI@TiO 2 nanocomposite is synthesized by a simple in-situ growth method. The two shells of polyaniline (PANI) and TiO 2 , hand in hand, play a key role to improve the electrochemical performance: First, the flexible properties of polyaniline (PANI) effectively accommodate the volume change of Si during the cycling. Second, the good mechanical feature of TiO 2 can maintain the structural integrity and attenuate the volume expansion of Si cores. Finally, both of polyaniline and the lithiated TiO 2 enhance the conductivity of Si, which promotes the electrons transport. Resulting in the Si@PANI@TiO 2 double core-shell nanocomposite exhibits remarkable synergy in large, reversible lithium storage, delivering a reversible capacity as high as 1027 mAh g−1 after 500 cycles and a superior rate capacity of 640 mAh g−1, at a current of 500 and 4000 mA g−1, respectively. This excellent cycling and high-rate capability can be ascribed to the unique and well-designed double core-shell structure with the synergistic effect between polyaniline (PANI) and TiO 2. Graphical abstract Image 1 Highlights • Double core-shell of Si@PANI@TiO 2 was prepared by a simple in-situ growth method. • PANI and TiO 2 shell played the important role for buffering the volume expansion of SiO 2. • TiO 2 shell maintain the integrity of the material structure. • PANI and the Lithiated TiO 2 improved the conductivity of Si. • Excellent cycling stability and superior rate capacity were demonstrated. [ABSTRACT FROM AUTHOR]