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Solutions with various concentrations of TiO2 were obtained and studied. The morphology of the carbon fiber with TiO2 coatings was investigated. The TiO2 concentration significantly effects on viscosity and coatings formed on carbon fibers. The relationship between TiO2 sol concentration and the mass oxide on the surface of carbon fibers was studied.

Nanoparticle growth during laser remelting was studied to provide references for optimizing technological parameters. The variations of nanoparticle sizes during laser remelting plasma-sprayed presetting of nanostructured Al2O3-13 wt%TiO2 coating were investigated on the basis of the classical theories of grain growth and by combining the temperature courses of nanoparticles at different positions, which were obtained from laser remelting finite element numerical simulation of the temperature field. Moreover, the effects of initial nanoparticle size and different remelting positions on grain growth were analyzed. A laser remelting test was conducted on the corresponding plasma-sprayed nanostructured coating. Results show that the overall trend of nanoparticle growth in the laser remelting test is consistent with theoretical calculation results, indicating that the classical theory of grain growth can offer some theoretical guidance to understanding nanoparticle growth during laser remelting.

To understand the effect of heat treatment of TiO2 modification for Ni-rich LiNi0.8Co0.1Mn0.1O2 cathode, the TiO2 coating layer is formed on the surface of LiNi0.8Co0.1Mn0.1O2 cathode by heat treat...

Surface modifications of metallic biomaterials can in great merit, improve the properties of the hard-tissue implants and in that way contribute to the success of the surgical implantation process. Coating deposition stands out as one of the many surface-modifying techniques that can be used to improve implant surface properties and, in turn, induce successful osseointegration. Deposition of the TiO2 layer on the surface of the metallic implants has a great potential to enhance not only their osseointegration ability but also their biocompatibility and corrosion resistance. In the present study, the possibility of successful deposition of the TiO2 layer on the surface of commercially pure titanium (CP-Ti), as the most commonly used metallic implant material, by spraying the colloidal nanoparticles aqueous solution in the electric discharge plasma at atmospheric pressure was investigated. To characterize the colloidal TiO2 nanoparticle solution, used for the coating deposition process, transmission electron microscopy (TEM) was utilized, while scanning electron microscopy (SEM) and optical profilometry were used to investigate the deposited surface layer morphology and quality. Estimation of the deposited film quality and texture was used to confirm that the arc plasma deposition technique can be successfully used as an advanced and easy-to-apply method for coating the metallic implant material surface with the bioactive TiO2 layer which favors the osseointegration process through the improvement of the implant surface properties. The TiO2 coating was successfully deposited using the arc plasma deposition technique and covered the entire surface of the CP-Ti substrate without any signs of coating cracking or detachment.

Ti and Ti alloys are bioinert materials and two frequent problems associated with them are bacterial infection and lack of osteogenic potential for rapid bone integration. To overcome the problems, the present study incorporated strontium (Sr) and silver (Ag) simultaneously into porous TiO2 coatings through a single-step technique, micro-arc oxidation (MAO). Incorporation of Sr and Ag brought no significant changes to coating micromorphology and physicochemical properties, but endowed TiO2 coatings with both strong antibacterial activity and osteogenic ability. Antibacterial activity increased with Ag contents in the coatings. When Ag content reached 0.58 wt%, the coating showed both excellent short-term (100.0%) and long-term (77.6%) antibacterial activities. Sr/Ag-containing coatings with 18.23 wt% Sr and 0.58 wt% Ag also presented good cytocompatibility for preosteoblast adhesion and proliferation, and promoted preosteoblast osteogenic differentiation both short-termly and long-termly. However, higher Ag content (1.29 wt%) showed toxic effects to preosteoblasts. In summary, MAO is a simple and effective way to incorporate Sr and Ag into porous TiO2 coatings and Sr/Ag-containing TiO2 coating with 18.5 wt% Sr and 0.58 wt% Ag has both good osteogenic activity and strong antibacterial capability short-termly and long-termly. Therefore, such coatings are valuable for clinical application to strengthen osseointegration and long-term high quality use of titanum implants.

A TiO2 coating was grown on a CdTe absorber by atomic layer deposition for stabilization against its photocorrosion during photoelectrochemical water splitting. Under simulated sunlight (AM 1.5G, 1...

In this study, functionally graded hydroxyapatite-titanium dioxide coating (FGC HA-TiO2), with bottom-up composition: 100% TiO2, 50% TiO2 -50% HA, 100% HA, was produced by sol-gel method on the Ti–6Al–4V alloy substrate. The XRD, FTIR and XRF results signified heat treatment of each coating's layer at 450 °C leads to desired phase achievement. The coherence, strength and scratch resistance of FGC HA-TiO2 in comparison with control samples namely; single-layer HA and double-layer HA-TiO2 coatings, were assessed by cross-sectional SEM images and nano-scratch test. According to the results, the insertion of the TiO2 layer improves the bonding strength of the coating to the substrate and grading the coating composition plays an essential role in upgrading the integrity and coherency of the coating. The contribution of the TiO2 intermediate layer and composition gradient on developing coating strength was 22% and 36%, respectively. The immersion test in the simulated body fluid (SBF) suggested bioactivity of the Ti–6Al–4V substrate enhances by coating.

Hydrophobic coatings are widely used in many areas from home to industry. However, the hydrophobicity can be easily degraded by adsorption of the atmospheric contaminations. In this study, a novel ...

Malzeme biliminin diğer alanlarda olduğu gibi tıp bilimine entegre olmasıyla biyomalzemelerin de çeşitliliği, gelişimi ve kullanım alanları artmaktadır. Bu çeşitlilik içerisinde yer bulan biyomalzemelerden biride NiTi alaşımlarıdır. Bu çalışma; şekil hafızalı NiTi alaşımının yüzey ve mekanik özelliklerinin iyileştirilmesi amacı ile Mikro Ark Oksidasyon (MAO) yöntemi kullanılarak TiO2 kaplamasının büyütülmesi üzerine odaklanmıştır. Büyütülen kaplamaların yapısal özellikleri SEM ve XRD cihazları kullanılarak analiz edilmiştir. Biyoaktivite özellikleri yapay vücut sıvısı (SBF) içerisinde bekletme testi analizi ile tespit edilmiştir. SBF içerisinde bekletme testleri sonrasında kaplanmış ve kaplanmamış şekil hafızalı NiTi altlıkların, bulundukları ortama Ni+2 salınımı kontrolü ise ICP-MS cihazı ile tespit edilmiştir. Büyütülen oksit tabakasıyla NiTi alaşımlarının kullanımını sınırlayan özellikleri önemli derece giderildiği gözlenmiştir. MAO yöntemiyle TiO2 kaplanmış NiTi altlıkların biyoaktif özelliklerinin arttığı ve 72. saatin sonunda hücre canlılığında NiTi altlığına kıyasla istatistik olarak herhangi bir sitotoksisiteye sahip olmadığı tespit edilmiştir. As material science is integrated into medical science as in other fields, the variety, development and usage areas of biomaterials increase. One of the biomaterials in this variety is NiTi alloys. This study was focused on the coating of TiO2 layer by using the method of Micro Ark Oxidation with the aim of the improvement of surface and mechanical properties of Shapedmemory and bio material NiTi alloy. Structural properties of the coatings were analysed by of SEM and XRD. In vitro ability was investigated by soaking the coated NiTi samples in simulated body fluid (SBF) at temperature 37 °C for various time periods. After soaking, Ni +2 release was applied to the media where coated and uncoated shape-memory NiTi samples are available, and its control was made by means of ICP-MS device. The results also show that Toxic and carcinogenic effects of Ni+2 release is significantly reduced by the TiO2 coating. Thus, it is observed that the properties that limit the use of NiTi alloys has been substantially fixed by MAO coating. It was found that the bioactive properties of the TiO2 coated NiTi substrate increased by MAO method and at the end of the 72 hour, there was no statistically any cytotoxicity in cell viability compared to the NiTi substrate. WOS:000661468600003

In this study, a nanostructured TiO2 coating was successfully prepared on a large-scale titanium plate by a simple one-step surface mechanical alloying (SMA) treatment. The coating was characterise...

The thermoplastic nylon denture base material is prone to discoloration because its amide bonds absorb water easily. Titanium dioxide (TiO2) nanoparticle have long been used as a denture base coating. Meanwhile, coffee contains chlorogenic and tanic acid, which can change the color of denture bases. The purpose of this study was to examine the effect TiO2 coating and duration of coffee immersion on discoloration of thermoplastic nylon denture base. Samples consisted of 24 thermoplastic nylon in square-shaped (30 x 30 x 2 mm), divided into 4 groups (n = 6). They were control (without TiO2 coating) and treatment (with TiO2 coating) groups, which then were immersed in coffee solution for 15 and 30 days. Discoloration test was conducted using spectrophotometer by measuring the delta absorbance of light before and after coffee immersion. The result showed that the lowest delta absorbance was in the 15-day treatment group (0.011 ± 0.005) and the highest was in the 30-day control group (0.077 ± 0.027). Two-way ANOVA test showed that TiO2 coating and coffee immersion had an effect on discoloration of thermoplastic nylon (p

Oxidation resistance of TiC–SKD11 composite has been improved through SiC/TiB2 based hybrid coating by a simple air spray process and subsequent transition to dense and stable phases in oxidation environment. As a result of the oxidation test at 700 °C for up to 50 h, the coated TiC–SKD11 composite exhibited excellent oxidation resistance characteristics compared with the uncoated TiC–SKD11 composite, and also compared to SUS431 and 17-4PH. The formation of a thermally stable, volume-expanded SiO2 and TiO2 coating layer with the aid of B2O3 by phase transition of TiB2/SiC based hybrid coating under oxidation atmosphere is the origin of the improved anti-oxidation ability of the TiC–SKD11 composite.

Titania (TiO2) based coatings are ceramic products with unique properties that make them widely applicable (e.g. in automotive industry, optoelectronics, chemical processing or medicine). Atmospheric plasma spray process enables to deposit TiO2 with addition of NiAl feedstock material which has an influence on coating cohesion and adhesion to substrate. However, the literature and technical notes give little information about parameters of spraying of TiO2-10 wt.% NiAl feedstock powders enables producing coating without nonuniformities including cracks and delamination form substrate. The aim of the work was to verify the parameters of plasma spraying by evaluation of the morphology and properties of manufactured the TiO2-10 wt.% NiAl coatings. Titania based coatings were deposited by means of atmospheric plasma sprayed on steel substrate using TiO2-10 wt.% NiAl feedstock powders. Morphology and microstructure were examined using light optical microscope (LOM) and scanning electron microscope (SEM). Coating chemical composition were analysed by means of SEM-EDS method. Coating surface topography and Knoop microhardness were determined. Porosity and thickness were evaluated by using quantities image analysis programme. Plasma spraying parameters used in our research allow to obtain uniform coating without cracks and delamination at coating-substrate interface. It acknowledges that uniformity of coating technological properties as well manufactured coatings can be put to wear tests, such as high temperature oxidation, corrosion, erosion or cavitation erosion resistance evaluation.

Kitchen cutting boards are one common source of microbial cross-contamination in foods. In this study, a method was developed to create an antimicrobial coating on HDPE cutting board using UV-activated TiO2 nanoparticles (NPs). The antimicrobial efficacy of the developed coatings was tested against E. coli O157: H7 for 3 h at 0.5 ± 0.05 mW/cm2 UVA light intensity. In addition, the effect of NP loading (0.0125, 0.0625, and 0.125 mg/cm2), and surface treatment of coatings by oxygen plasma for 1–15 min on the bactericidal efficacy was investigated. Further, the bactericidal efficacy of the TiO2 coated cutting board on repeated use (i.e. 1, 2, 3 and 5 times) was also evaluated. The results showed that by increasing the NP loading from 0 to 0.125 mg/cm2 has increased the log reduction from 0.37 to 1.18 CFU/cm2. However, no significant difference (P > 0.05) in the reduction was observed between NP loadings at 0.0625 and 0.125 mg/cm2. Oxygen plasma treatment of the coated surfaces for 5–15 min significantly increased (P ≤ 0.05) the log reduction compared to control sample without plasma treatment. Under the tested conditions, TiO2 coating with 0.0625 mg/cm2 NP loading followed by oxygen plasma treatment for 5 min was found to achieve the greatest reduction up to 2.67 log CFU/cm2. Also, the coated-surfaces were found to retain the original bactericidal property even after up to 5 times washing treatment. The developed TiO2 coating on cutting board showed promise to mitigate the risk of microbial cross-contamination by providing a stable antimicrobial activity for extended use. Plasma treatment further enhanced the bactericidal property of the developed coatings without affecting physical stability.

PurposeNanostructured titanium dioxide (TiO2) coatings can potentially address the current surge in façade cleaning cost, maintenance and labour problems. The purpose of this paper is to investigate potential maintainability issues and design challenges concerning the effective performance of TiO2façade coatings’ hydrophilic properties, especially in tropical environments such as Singapore. This paper aims to establish a list of green maintainability design criteria to help minimise future TiO2façade coating issues when this coating is applied on commercial buildings with concrete and stonemasonry façade materials.Design/methodology/approachA mixed-mode approach that includes a literature review, site investigation, instrumental case studies and expert interviews is used in this study.FindingsTiO2coatings help improve façade performance whilst offering environmental benefits to society. This study reports that green maintainability design criteria are vital requirements in designing sustainable buildings at the outset. The identified defects and issues will aid in ensuring the effectiveness of TiO2application in building façades.Originality/valueThis study acts as a foundation for future researchers to strengthen this little researched area, serves as a useful guide in preventing possible TiO2coating issues and promotes industry awareness of the use of TiO2façade coatings.

Various strategies are being developed for the prevention of implant-related infections. One of them is the encapsulation of antimicrobial drugs in inorganic containers that can be released at the site of the implant. However, the attachment of such containers onto implant surfaces may be a challenge. In this study, it is demonstrated that CeO2 nanocontainers can be added to a TiO2 coating on glass surfaces. The structure, crystal phase and surface properties of the nanocontainers were characterized by transmission electron microscopy, scanning electron microscopy (SEM), powder X-ray diffraction, infrared spectroscopy, Raman spectroscopy and a zetasizer. The coatings were analyzed by SEM and energy-dispersive X-ray spectroscopy to determine their homogeneity and ensure CeO2 encapsulation. The coatings were stable in air over prolonged time periods (> 6 months) and therefore hold promise for pursuing in biomedical applications.

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.

The coronary artery stent has been widely used in clinic. In-stent restenosis was mainly caused by the excessive proliferation of smooth muscle cell and the inflammation due to the metal ion released from stent scaffold of the drug-eluting stent. Thus, to reduce the in-stent restenosis and promote the vascular endothelialization have become a hot research point in this area. In this paper, a nano-TiO2ceramic coating was deposited on 316L stainless steel to reduce the metal ion release and to inhibit the inflammation reaction. An endothelia cell selective adhesion peptide Arg-Glu-Asp-Val (REDV) coating was prepared on the ceramic coating by a polydopamine technology to promote the endothelialization. The corrosion test indicated that nano-TiO2ceramic film could effectively decrease the nickel ion released from 316L stainless steel. REDV/TiO2coating could promote the endothelial cell adhesion and proliferation, meanwhile REDV/TiO2coating could also increase the nitric oxide concentration. Bare metal stent, TiO2-coated stent and REDV/TiO2-coated stent were implanted in the iliac arteries of rabbit model. In-stent restenosis and re-endothelialization were evaluated at 28 days post-implantation of the stents. The results showed that REDV/TiO2-coated stents could effectively reduce in-stent restenosis and promote re-endothelialization in comparison with TiO2-coated drug-eluting stent and bare metal stent. These results suggest that REDV/TiO2-coated drug-eluting stent maybe a good choice of the application for coronary artery disease.

Sol-gel dip-coating technique was utilized to prepare Ag-TiO2 coating with additive (Degussa P25) on unglazed ceramic tiles. Three different numbers of coating layers (5, 7 and 10 layers) were deposited on unglazed ceramic tiles made of waste glass. The coatings were sintered at 500 °C with the heating rate of 2 °C/min. The crystalline phase and cross sectional areas of the coatings were evaluated using GAXRD and SEM analysis, respectively. Results showed that the average thickness of the coating increased from 7 µm to 9 µm and to 12 µm for 5, 7 and 10 coating layers, correspondingly. Coating of 10 layers exhibited a high crystallinity of anatase phase, a good surface morphology without significant cracks, and a homogeneous coating compared to the 5 and 7 layers of coating, which suggested a better performance in Ag-TiO2 coating.

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.

Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode particles were coated with anatase TiO2 layer to improve its cycle stability. The TiO2 coating was synthesized by the hydrolyzation method and subsequent annealing treatment ranging from 500 ℃ to 600 ℃. The well-ordered layered α-NaFeO2-type structure survives in the TiO2 coating process. The nanothick anatase TiO2 layer coveres on the surface of NCM811. The annealing temperature of coating was controlled to improve the electrochemical performances. The TiO2-coated NCM811 cathode annealed at 600 ℃ demonstrates the optimal capacity retention of 104.9% after 100 cycles at the current rate of 0.1 C, in contrast to 64.1% of pristine NCM811 and 96.7% of the coated sample annealed at 500 ℃.

In the present work, a Cu-incorporated TiO2 coating was successfully fabricated through a one-step micro-arc oxidation (MAO) of Ti in a solution containing 10 g/L ethylene diamine tetraacetic acid cupric disodium (Na2Cu-EDTA). Interestingly, different colour appearances of the resultant Cu-incorporated TiO2 coating were noticed with the presence of black area at the edge and brown area in the centre. Further, microstructural characterization reveals that, unlike the central brown area with high amount of Cu+, the peripheral black area is mainly enriched in Cu2+, which exhibits a two-layered structure consisting of TiO2 inner layer and porous Ca, P-rich outer layer containing nano-sized hydroxyapatite (HA) crystals. Finally, biological examination reveals that the peripheral black area exhibits both improved bone formability and enhanced antibacterial capability in comparison to the central brown area. Based on the observation, the coating formation mechanism is proposed, which provides valuable guidance for the utilization of MAO method in the field of bio-medical materials.

Use of silicon dioxide (SiO2) and titanium dioxide (TiO2) have been widely investigated individually in coatings technology, but their combined properties promote compatibility for different innovative applications. For example, the photocatalytic properties of TiO2 coatings, when exposed to UV light, have interesting environmental applications, such as air purification, self-cleaning and antibacterial properties. However, as reported in different pilot projects, serious durability problems, associated with the adhesion between the substrate and TiO2, have been evidenced. Thus, the aim of this work is to synthesize SiO2 together with TiO2 to increase the durability of the photocatalytic coating without affecting its photocatalytic potential. Therefore, synthesis using sonochemistry, synthesis without sonochemistry, physical characterization, photocatalytic evaluation, and durability of the SiO2, SiO2@TiO2 and TiO2 coatings are presented. Results indicate that using SiO2 improved the durability of the TiO2 coating without affecting its photocatalytic properties. Thus, this novel SiO2@TiO2 coating shows potential for developing long-lasting, self-cleaning and air-purifying construction materials.

Porous silicon (pSi) is a sponge-like material obtained by electrochemical etching of a crystalline silicon wafer. Due to quantum confinement effects, this material is photoluminescent and this is a fundamental property from the perspective of bioimaging applications. Limitations in nanomedicine to the use of photoluminescent pSi structures are mainly due to optical quenching in an aqueous environment and to the adverse effects of reactive groups introduced by etching procedures. In this work, we exploited an inorganic TiO2 coating of pSi microparticles by Atomic Layer Deposition (ALD) that resulted in optical stability of pSi particles in a biological buffer (e.g. PBS). The use of a rotary reactor allows deposition of a uniform coating on the particles and enables a fine tuning of its thickness. The ALD parameters were optimized and the photoluminescence (PL) of pSi–TiO2 microparticles was stabilized for more than three months without any significant effect on their morphology. The biocompatibility of the coated microparticles was evaluated by analyzing the release of cytokines and superoxide anion (O2−) by human dendritic cells, which play an essential role in the regulation of inflammatory and immune responses. We demonstrated that the microparticles per se are unable to significantly damage or stimulate human dendritic cells and therefore are suitable candidates for nanomedicine applications. However, a synergistic effect of the microparticles with bacterial products, which are known to stimulate immune-response, was observed, indicating that a condition unfavorable to the use of inorganic nanomaterials in biological systems is the presence of infection diseases. These results, combined with the proved PL stability in biological buffers, open the way for the use of pSi–TiO2 microparticles as promising materials in nanomedicine, but their ability to increase immune cell activation by other agonists should be considered and even exploited.

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.

Often Glass products achieve their component functionality only by a specific surface finishing, such as coating or patterning. Compared to vacuum based CVD and PVD coating techniques, the equipment for wet-chemical deposition of sol-gels is less expensive. Heat is needed for a chemical reaction to cure gels and form solid functional layers. In this study, sols with titanium and zirconium were applied on glass substrates by dip coating. The investigated layer thicknesses were in the range between 320 nm and 650 nm. The gel layers were annealed with CO2 laser radiation. Different scanning speeds and laser powers were investigated. Microscope images were used to compare the laser-annealed layers with oven-annealed layers. To conclude, the oven-process can be substituted by laser annealing and additionally enables local patterning. This allows gradient coating solutions for architecture applications.

Al2O3–40% TiO2 coating is deposited on Superni 601 and Superco 605 superalloys by low-velocity oxy-fuel (LVOF) process. LVOF sprayed coating is characterized for surface roughness, microhardness, scanning electron microscopy and X-ray diffraction analysis. Hot corrosion of the coated and uncoated superalloys have been evaluated in an aggressive environment of Na2SO4–82% Fe2(SO4)3 under cyclic conditions at temperatures of 800 and 900°C. The microhardness and surface roughness values of the as-sprayed coatings are found to be in the range of 742–946 Hv and 14.40–14.80 μm, respectively. Al2O3–40% TiO2 coating on both the superalloys has indicated protective behaviour during hot corrosion studies.

TiO2-coated Co/C catalysts prepared by atomic layer deposition (ALD) were used to study the effect of TiO2 overcoating on a Co/C catalyst for electrochemical water oxidation. The Co/C catalyst with a thin-layer overcoating of TiO2 (ALD(TiO2)-Co/C) demonstrated 2.5 times higher turnover frequency (TOF) than the Co/C catalyst for the reaction. The TOF of the ALD(TiO2)-Co/C catalyst increased when the ALD(TiO2) coating cycle number was increased from 5 to 60. In addition, the stability of the 60 cycle ALD(TiO2)-Co/C catalyst was enhanced compared to the Co/C catalyst. This work shows how the ALD synthesis technique can be used to improve the catalytic activity and stability of nonprecious-metal-based catalysts like Co/C for electrochemical water oxidation.

In the paper UHMWPE coating with different materials is analysed. Such coatings are made using magnetron sputtering method. The friction tests of these coatings are accomplished. SPM surface morphology images of coatings are analysed before and after the friction test. It was determined that Co+TiO2 coating altered the least after the friction tests. For this reason, its durability and wear resistance is the highest in comparison with all the analysed coatings.

Titanium based implant materials are confronting poor osteointergtation and bacterial infection issues when giving full play its desirable mechanical properties to hard tissue replacement applications. On the basis of plasma electrolytic oxidation (PEO) synthesised porous CaP–TiO2 coatings, which possess favourable biological performance but poor antimicrobial potential, in this work, surface nanofunctionalisation was performed using hydrothermal treatment in order to endow these coatings with antimicrobial ability. After surface nanofunctionalisation, the coatings were decorated with numerous nanoscale petal-like topography without obviously changing the original PEO synthesised porous structure and anatase titania predominant phase composition. The effects of antibacterial evaluation suggest that the nanofuntionalised CaP–TiO2 coating possessed excellent antimicrobial activity against both Escherichia coli and Staphylococcus aureus species. The antimicrobial efficacies were all close to 100% com...

Failure of components due to high temperature oxidation is the major degradation mechanism in boiler and gas turbine industries. Superalloys having superior mechanical properties and creep resistance are used in these applications but lack resistance to oxidation under aggressive environments. Protective coatings are used to improve their oxidation resistance in such applications. In the present investigation, Al2O3–40%TiO2 coating was deposited on superni 718 and superni 601 superalloys by low velocity oxy fuel process. The as sprayed coating was characterised for microhardness, surface roughness, scanning electron microscopy and X-ray diffraction analysis. High temperature oxidation behaviour of Al2O3–40%TiO2 coated and uncoated superni 718 and superni 601 superalloys has been evaluated at the elevated temperatures of 800 and 900°C for total duration of 50 cycles under cyclic conditions. Each cycle consisted of keeping the samples for 1 h at the elevated temperature followed by 20 min cooling in...

Infection associated with titanium implants remains the most common serious complication after surgery. In this work, Cu-doped antibacterial TiO2 coating was synthesized by micro-arc oxidation of titanium in an electrolyte bearing Cu nanoparticles. Surface morphology and structure of the coating were characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results indicated that Cu nanoparticles were not only distributed on the surface and inside the pores but also embedded in the coating. Cu mainly exists in the Cu2+ state in the TiO2 coating. The Cu-doped coating exhibited excellent antibacterial activities against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus).

PBO fiber is the most excellent high performance fiber. But it is a kind of photosensitive material and is prone to degrade under ultraviolet (UV) radiation, which results in the changes of the fiber mechanical properties, finally affects the using of the material. In present paper, Titanium tetrabutoxide was used as solgel precursor of a nanosized TiO2coating to improve the photostability of PBO fibers. The nanosized TiO2coating was characterized by XRD. The influence of the coating on UV-durability of PBO was investigated by an accelerated UV-ageing method. Results of mechanical measurement showed that after exposing to UV light for 160 h, the fibers without TiO2coating degraded sharply, 7.01% of strength and 11.42% of break extension only remained, whereas 45.61% of strength and 68.56% of break extension still remained for the TiO2coated fibers. SEM analysis showed no significant surface morphological change on the coated fibers after the exposure, while some latitudinal crack fractures appeared on the uncoated PBO fibers.

Using plasma spraying equipment to prepare Al2O3-13wt%TiO2 coating on Q235 substrate. Study of its organization and performance, test the performance of coating microhardness and the resistance of friction and wear resistance then optimize the spraying process parameters. The surface of the coating performance was studied by SEM. The results show that, Coating microhardness can be as high as 1132HV, Far more than the matrix microhardness. The minimum average wear weightlessness of Sample surface is 0.95mg. Greatly improve the wear resistance

Porous TiO 2 coatings were produced on commercially pure Ti substrates by micro-arc oxidation (MAO) in 1.0 M H 2 SO 4 electrolyte for different anodizing times. Their mechanical properties were assessed by means of instrumented indentation, XRD residual stress measurements and scratch resistance tests. The rutile/anatase ratio increased from ~ 0 up to 84% in the 10–360 s anodizing time range, with further increase of coating thickness, porosity and roughness. Titania coatings produced for 180 and 360 s had poor adhesion and uneven surfaces with spontaneous detachment from the substrate. Coating hardness ranged from 3.5 up to 4.0 GPa (close to Ti), whereas the effective elastic modulus varied from 110 up to 120 GPa (19% lower than Ti), regardless of the substrate effects. Coatings exhibited tensile residual stresses, while the substrate compressive stress increased forming a plateau at about − 110 MPa for anodizing time longer than 60 s. The presence of such hardened layer beneath the interface improved the coating integrity in the scratch tests under the severe tribological condition, thereby increasing about tenfold the detachment critical load for the samples prepared in the 10–60 s MAO time range. Therefore, the 60 s anodizing time can be a useful reference line for producing mechanically resistant porous titania coatings.

Nano-structured Al2O3-13%TiO2 coating was deposited by air plasma spraying. Wear properties of the coatings under different load trough SRV friction and wear testing machine were studied, the results showed that wear mass loss of Al2O3-13%TiO2 coating by plasma spraying slide with ZrO2 and Si3N4 increase with load increasing, but the difference is that wear loss of coaing slide with Si3N4 ¬is lower than the coating slide with ZrO2 when load is less than 40N. Opposite phenomenon will occur when load is higher than 40N.The wear surface morphology was analyzed trough scanning electron microscopic, the results showed that coating slided with Si3N4 ball when matching at low loads, with a shallow furrow shape grinding. There were wide and deep furrows while at higher loads. Coating slide with ZrO2 ball has no obvious cracks, no layer spalling.Wear was occurred by micro cutting.

Influences of the TiO2 coating and thermal annealing on the photoluminescence (PL) properties of ZnS nanowires were investigated. ZnS nanowires were synthesized by thermal evaporation of ZnS powder and then coated with TiO2 by using the sputtering technique. The PL emission of ZnS nanowires can be significantly enhanced without nearly changing the wavelength of the emission by coating them with a TiO2 layer with an appropriate thickness and then annealing them in an Ar atmosphere. The optimum TiO2 coating layer thickness for the highest PL emission enhancement was found to be about 6.5 nm. The PL emission of the ZnS-core/TiO2-shell coaxial nanowires is degraded by annealing in an oxygen atmosphere whereas it is enhanced by annealing in an argon atmosphere.

The Al2O3-TiO2 coating for turbine blades is being used since long. During the last decades,a large number of papers have been published, but work on property assessment of Al2O3-TiO2coating on rotating component from tribological point of view is very less. This paper assessesthe wear behaviour of Al2O3-TiO2 coating on inconel 601. The Al2O3-TiO2 coating on inconel 601is deposited by plasma spray process. The SEM results show that above 300 oC, the frictioncoefficient decreases due to softening of coating material. The wear rate increases with increasein temperature. The coating showed brittle fracture at higher temperature. Other test results haveshown the drastic changes in property due to load and temperature.Defence Science Journal, 2008, 58(4), pp.582-587, DOI:http://dx.doi.org/10.14429/dsj.58.1680

This article presents results from a pilot study comparing condensation patterns on small glass samples with different surface properties. Experiments were carried out on three commercial glass samples (clear float, TiO2-coated and SnO2-coated) to see how water condensed on the different surfaces. The experiments were carried out under a clear night sky in Uppsala, Sweden. It was found that the pane with the low-emittance coating stayed clean of condensation longer than the other two. In the morning, the water layer on the TiO2-coated sample was smeared out so that it was possible to see through that pane, while the view through the other two was still blurred. The TiO2 coating does not prevent condensation, but makes it easier to see through the water layer. These simple tests indicate noticeable differences between different surface materials and also that these effects can be studied by exposing small samples to a clear night sky without having to perform full scale tests.

The precursor solution of titanium oxide coating was prepared by using titanium-oxygen sulfide. Solution with PH value of 8.5 was used to for coating on the surface of glass through dipping. The coatings were analyzed with DSC, AFM and XRD. The hydrophilic results of titanium oxide coating were obtained according the water contact angle measurement in the sunlight irradiation condition. The experimental results demonstrate that this solution is a good precursor for coating of titanium oxide, and the coatings treated at a higher temperature have shown good hydrophilic property.

The present paper presents a short overview of the TiO2 coating technologies that have been applied for a variety of applications, including the formation of photocatalysts for the decomposition of water and the fabrication of antipollution building materials through functional coatings. Several coating processing procedures are outlined, including sol–gel technique, screen printing, roll on method and spraying procedure.

In this work, nano-TiO2 powders were deposited onto Ti-6Al-4V substrates to produce coating using plasma spraying. The TiO2 coatings were respectively by acid, alkali and heat treatment to produce the bioactive surface. The bioactivity of TiO2 coating was examined by simulated body fluids test. The results obtained indicated apatite was formed on the surfaces of nano-TiO2 coatings treated by H2SO4, HCl and HF solutions, while it could not be formed on the surface of the nano-TiO2 coating treated by NaOH solution at low concentration. After alkali attack and heat treatment at 600°C, the bioactivity of nano-TiO2 coating disappeared.

Nanostructured and conventional Al2O3-3 wt% TiO2 coatings were deposited by atmospheric plasma spraying. The wear and friction properties of both coatings against a steel ball under dry friction conditions were examined. It was found that the wear resistance of the nanostructured Al2O3-3 wt% TiO2 coating was superior to that of the corresponding conventional counterpart. The improvement in wear resistance of the nanostructured coating was attributed to its higher toughness and cohesion strength between splats. As for the nanostructured coating, the wear mechanism was mainly adhesion with micro-abrasion at low loads (20 N). At high loads (80 N), the wear of the nanostructured coating was controlled by plastic deformation and associated delamination along the splat boundaries, which was similar to that of the conventional coating at low loads. However, the failure of the conventional coating was predominantly brittle fracture within the splats and delamination between splats at high loads.

Nanostructured and conventional Al2O3–3 wt.% TiO2 coatings were deposited by atmosphere plasma spraying. The tribological properties of both coatings against a silicon nitride ball were examined in the temperature range from room temperature to 600 °C. The friction coefficients of both coatings were similar and ranged from 0.85 to 0.10. The wear rates of both coatings increased with the increase in temperature. At room temperature, a protective layer consisting of silicon oxide existed on the worn surface of both coatings and led to the lower wear rate. At high temperature, brittle fracture occurred on the worn surfaces of both coatings, which was enhanced with the increase of temperature. But, the wear resistance of the nanostructured coating was superior to that of the conventional coating except at room temperature. The improvement in wear resistance of the nanostructured Al2O3–3 wt.% TiO2 coating was discussed in the terms of its microstructural characteristics.

To inhibit the metal catalytic coking and improve the oxidation resistance of TiN coating, rutile TiO2 coating has been directly designed as an efficient anticoking coating for n-hexane pyrolysis. TiO2 coatings were prepared on the inner surface of SS304 tubes by a thermal CVD method under varied temperatures from 650 to 900 °C. The rutile TiO2 coating was obtained by annealing the as-deposited TiO2 coating, which is an alternative route for the deposition of rutile TiO2 coating. The morphology, elemental and phase composition of TiO2 coatings were characterized by SEM, EDX and XRD, respectively. The results show that deposition temperature of TiO2 coatings has a strong effect on the morphology and thickness of as-deposited TiO2 coatings. Fe, Cr and Ni at.% of the substrate gradually changes to 0 when the temperature is increased to 800 °C. The thickness of TiO2 coating is more than 6 μm and uniform by metalloscopy, and the films have a nonstoichiometric composition of Ti3O8 when the deposition temperature is above 800 °C. The anticoking tests show that the TiO2 coating at a deposition temperature of 800 °C is sufficiently thick to cover the cracks and gaps on the surface of blank substrate and cut off the catalytic coke growth effect of the metal substrate. The anticoking ratio of TiO2 coating corresponding to each 5 cm segments is above 65% and the average anticoking ratio of TiO2 coating is up to 76%. Thus, the TiO2 coating can provide a very good protective layer to prevent the substrate from severe coking efficiently.

TiO2 coatings are known to protect some metals, including type 304 stainless steel, from corrosion on the basis of its reductive energy generated under UV irradiation. A TiO2 coating is coupled with a WO3 coating as an electron pool, in which the reductive energy can be stored. A WO3 film on a type 304 stainless steel plate can be charged by a UV-irradiated TiO2 coating on the same plate, in a 3 wt % NaCl aqueous solution, pH 5. The charged WO3 coating can protect the stainless steel plate from the corrosion for a while even after the UV light is turned off. Thus, the TiO2 coating protects the plate and charges the WO3 coating during the day, and the charged WO3 coating protects the plate during the night. The charge−discharge cycles are repeatable. A TiO2−WO3 composite coating also has the same effects.

The aim of this study was the investigation of a copper-filled TiO2 coating, that in vitro showed good antibacterial properties combined with good tissue tolerance in an animal model. To better understand the antibacterial mechanism of the bioactive coating the release of copper (Cu) ions over time was monitored to be able to detect possible threats as well as possible fields of application. 30 New Zealand White rabbits were divided into two groups with 15 animals per group. In group 1 (control group) Ti6Al4 V bolts were implanted into the distal femur, in group 2 the Ti6Al4 V bolts were coated with four TiO2-coatings with integrated Cu(2+)-ions (4 × Cu-TiO2). Blood tests were performed weekly until the animals were sacrificed 4 weeks postoperative. The maximum peak of Cu and ceruloplasmin concentration could be seen in both groups one week postoperative, whereas the Cu values in group II were significantly higher. The Cu concentration in both groups approximated the initial basic values 4 weeks postoperative. The 4 × Cu-TiO2 coating tested in our rabbit model for total knee arthroplasty is an active coating that releases potentially antibacterial Cu(2+) for 4 weeks with a peak 1 week postoperative. The bioactive coating could be a promising approach for a use in the field of implant related infection, orthopaedic revision and tumor surgery in the future.

Wear of plasma-sprayed TiO 2 coating against stainless steel was tested with a block-on-ring arrangement at different loads and sliding speeds. It was found that wear mass loss of TiO 2 coating increased with increase in loads but decreased with increase in sliding speeds. The mechanism was explained in terms of grinding wear, adhesive wear, micromechanical delamination wear, plastic deformation wear, melting wear and formation of Fe 2 O 3 Fe 3 O 4 thin film.

In order to improve the surface characteristics of polymethylmethacrylate (PMMA), oxide thin-film coatings were applied using the sol-gel dip-coating technique. The Si(OC2H5)4 (TEOS), CH3Si(OC2H5)3 (MTES) or Ti(O-i-C3H7)4 (TIP) was used as a starting material for SiO2 or TiO2 coating. The hardness of the alkoxy-derived oxide-coated PMMA was increased from 200 MPa for non-coated PMMA with increasing film thickness. By optimizing the heating conditions and the hydrolysis conditions, and by repeating the dip-coating/heating processes, a hardness as high as 325 MPa was achieved in the PMMA triply coated with the TEOS-derived SiO2 film using the withdrawal velocity of 0.30 mms−1 and heat treatment at 80°C. The increase in hardness with the thickness of coating film was saturated before reaching that of bulk silica-dried gel (ca. 500 MPa), which may be due to the increased porous nature of the thick films.