Incorporation Of TiO2 Particles Research Articles

The effect of positive and reverse current cycles on the wettability, morphology, and corrosion behaviour of electrodeposited nickel matrix layer

ABSTRACT In this study, Ni-TiO2 coatings were formed using a multi-step pulse method with positive and, in some cases, reverse current steps. All coatings were produced at a current density of 4 A dm−2 and a frequency and duty cycle of 10 Hz and 10%, respectively with a thickness of 30 µm. The results showed that by applying the reverse current cycle, the codeposition of TiO2 particles in the coating decreased and the morphology of the coating became irregular. It was found that the effect of the wetting angle of the coating is greater than the incorporation of TiO2 particles on the corrosion behaviour of the coating. Thus, a coating was created with a positive 4-step pulse current with the lowest amount of TiO2 particles (7.7 vol.%) having the highest resistance against corrosion. The sample had compact morphology and high wetting angle (82.61o֯).

Parametric studies on dry sliding wear behaviour of Al-7075 alloy matrix composite using S/N ratio and ANOVA analysis

Al7075/10 wt% TiO2 alloy composite has been fabricated by the stir casting method to investigate the influence of wear parameters. The microstructure of the produced composite was analyzed by scanning electronic microscopy. A pin-on-disc rig was used to carry out the wear test on produced composite under dry sliding conditions. The three wear control parameters such as load, sliding velocity and sliding distance were chosen to study the effects on the wear rate and coefficient of friction of composite. The experiments were planned as per L9 orthogonal array based on Taguchi’s design of experiments. The signal-to-noise ratio and analysis of variance techniques were employed to determine the optimum combination of parameters and the significant contribution of each parameter on the responses. The results exposed that the load was the most predominant factor affecting the wear rate and coefficient of friction followed by the sliding distance and sliding velocity. Finally, the regression equations were developed to predict the responses. The worn surface morphology of composite noticed that TiO2 reinforcement protects the matrix alloy from removal of material at all conditions. This investigation revealed that the wear resistance of the Al7075 alloy can be enhanced by the incorporation of TiO2 particles.

MHD Supported Electroreduction of Formate Nickel Complexes with Simultaneous Incorporation of TiO2 Particles

MHD Supported Electroreduction of Formate Nickel Complexes with Simultaneous Incorporation of TiO2 Particles

Synthesis, structural characterization, mechanical and wear behaviour of Cu-TiO2-Gr hybrid composite through stir casting technique

Manufacturing copper metal matrix composite (CMMCs) through stir casting method results in numerous desirable benefits. This research is dedicated on fabricating Cu with 0, 3, 6 and 9 wt% TiO2 and 1% Gr CMMCs. The reinforcement particles were added to Cu molten metal at 1200 °C. The cast CMMCs have been analysed using advanced characterization method viz. XRD, FESEM and EDAX. XRD peaks confirm the presence of hard ceramic TiO2 particles in the matrix. Grain refinement takes place in the composite due to TiO2 particles. Two kinds of distribution are observed in the micrographs. By increasing the content of TiO2 and Gr, agglomeration occurs within the grain boundaries and reduces the grain size. As a result, hardness and ultimate tensile strength are improved by the incorporation of TiO2 particles and the corresponding strengthening mechanisms involved have been discussed.

A multifunctional cotton fabric using TiO2 and PCMs: introducing thermal comfort and self-cleaning properties

The development of materials with multiple functionalities is a market imperative that places new challenges on textile processing. The purpose of this study was to establish the conditions to obtain a cotton material that is comfortable, with self-cleaning and antimicrobial properties. For this purpose, microcapsules of phase change materials (mPCM) and titanium dioxide nanoparticles (TiO2 NP) were applied. The resulting fabrics were characterized with resource to infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), contact angle and scanning electron microscopy (SEM). The self-cleaning properties of treated fabrics were also analysed based on the photocatalytic ability of coated fabrics. Therefore, the decomposition of methyl orange (MO) and the degradation of red wine and curry spots under the irradiation of a solar simulator were analysed. Thus, the incorporation of TiO2 particles into the cotton fabric promoted self-cleaning and antibacterial characteristics, but the presence of PCM combined with TiO2 increases the bioactivity of materials.

Electrochemical synthesis and properties of iron–titanium dioxide composite coatings

Deposition of Fe/TiO2 composite coatings from a colloidal methanesulfonate electrolyte containing titanium dioxide hydrosol was studied. The TiO2 content in the composite increases with increasing the dispersed phase content and decreasing the current density. Incorporation of TiO2 particles into the iron matrix resilts in an increase in the microhardness of the deposit. The electroplated Fe/TiO2 composite coating was used as a heterogeneous photocatalyst for the decomposition of an organic dye under the action of UV radiation.

Implementation of nanotechnology in improving the environmental compliance of construction projects in the United States

ABSTRACTNanotechnology, defined as the science of very small matter called nanomaterial, comprises the study of chemical and physical properties of particles which are structured in sizes ranging from 1 to 100 nm. At this size range, nanomaterial exhibits superior chemical and physical characteristics as compared to those displayed while existing in normal size. To date, multiple nanotechnology research centers within the United States are investigating the potential use of different types of nanoparticles as titanium dioxide (TiO2) in the construction industry to attain superior characteristics of building materials, improve their rating as environmentally friendly material, and improve the overall LEED rating of construction projects.The major impediments to the widespread implementation of nanotechnology include high nanomaterial cost, lack of industrial experience, and absence of standard specifications for building materials incorporating nanoparticles. This research article presents a research effort performed to improve the ability of construction material to attain self-cleaning properties through the incorporation of TiO2 particles in the concrete surface layers. Nanosized TiO2 particles were able to dissolve induced stains in the presence of sunlight. This chemical reaction, known as photocatalysis, can be successfully used in improving the environmental compliance of construction projects at the US market.

Formation of photocatalytic plasma electrolytic oxidation coatings on magnesium alloy by incorporation of TiO2 particles

Abstract Photocatalytically active plasma electrolytic oxidation coatings on AM50 Mg alloy are reported in the present work. The photocatalytic activity was achieved via introduction of anatase (TiO2 particles) to the treatment bath. The photocatalytic performance of the coating was evaluated by measuring the degradation rate of aqueous methylene blue solution and was primarily related to the anatase content on the coating surface. Lower treatment voltage and a higher amount of particles in the electrolyte can be used to incorporate more anatase into the layer and generate superior photocatalytic coatings. The tailored and functionalized surface provides new functionality for magnesium alloys.

Electrochemical Response of Al2O3-MoO2-TiO2 Oxide Films Formed on 6061 Al Alloy by Plasma Electrolytic Oxidation

The purpose of this study is to investigate the electrochemical response of Al2O3-MoO2-TiO2 oxide films fabricated on 6061 Al alloy by plasma electrolytic oxidation (PEO). The coatings were fabricated under alternating current conditions using an alkaline-silicate-molybdate electrolyte with TiO2, and the results were compared to those without TiO2. Microstructure observations revealed that when TiO2 was added to the electrolyte, the average size and area fraction of the micro-pores of the oxide layer coated in the electrolyte incorporating TiO2 were respectively smaller. The results of potentiodynamic polarization test in 3.5 wt% NaCl solution clearly indicated that the corrosion resistance of the oxide films was significantly improved by the incorporation of TiO2 particles. High corrosion resistance of the Al2O3-MoO2-TiO2 oxide films was also revealed by impedance tests and analyzed in relation to the equivalent circuit model.

Effect of surfactants on the coating properties and corrosion behaviour of Ni–P–nano-TiO2 coatings

In this paper, the effects of two different types of surfactants on the properties of Ni–P–TiO2 coating on low carbon steel substrate were investigated. Sodium dodecyl sulphate (SDS) — anionic surfactant and dodecyl trimethyl ammonium bromide (DTAB) — cationic surfactant were used for the deposition. Deposits were characterized by a high resolution scanning electron microscope (HR-SEM), an energy dispersive X-ray spectrometer (EDS), and X-ray diffraction (XRD) to study the surface morphology, composition and crystal structure of the coatings respectively. In addition, the influence of surfactants on the corrosion behaviour of Ni–P–TiO2 coatings was also examined using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 3.5wt.% sodium chloride solution. The results showed that at an optimum concentration of cationic surfactant DTAB, uniform distribution of TiO2 particles with no defects was observed. The corrosion properties were improved by the incorporation of TiO2 particles in the Ni–P matrix. The increase in corrosion resistance of the Ni–P-TiO2 coatings significantly depends on the surfactant and its concentration.

Dye-Sensitized Solar Cells Based on Porous Hollow Tin Oxide Nanofibers

Porous hollow tin oxide (SnO2) nanofibers and their composite with titanium dioxide (TiO2) particles (Degussa P25) were investigated as a photoanode for dye-sensitized solar cells. Incorporation of TiO2 particles in porous hollow SnO2 fibers enhanced the power conversion efficiency ( $\eta )$ from 4.06% to 5.72% under 100-mW/cm $^{2}$ light intensity. The enhancement of efficiency was mainly attributed to increase in current density ( $J_{\rm sc}$ ) and improvement in fill factor (FF). Increase in $J_{\rm sc}$ was caused by higher dye loading as indicated by UV–Vis absorption spectra and the improvement in FF was attributed to faster charge transport time as obtained from transient analysis. The microstructure of SnO2 fibers was studied using transmission electron microscope, scanning electron microscope, and X-ray diffraction. The electron transfer and recombination life times were studied using transient analysis, whereas interfacial charge transfer was studied using electrochemical impedance spectroscopy.

Nanocomposite Ni–TiO2 coatings produced by pulsed electroplating

Nanocomposite Ni–TiO2 coatings were prepared on mild steel substrate by pulse electroplating with controlled duty cycle and frequency. A systematic study of Ni–xTiO2 coatings with different TiO2 concentrations (x = 0–20 g L−1) has been conducted. The coatings were characterised using SEM, XRD, microhardness and wear tests. It was found that incorporation of TiO2 particles decreased the grain size and improved the mechanical property of Ni coatings. The mechanical properties of Ni–TiO2 coatings increased to the optimum value when the concentration of TiO2 powder was 10 g L−1. The effect of TiO2 nanoparticle concentration on the surface morphology, microstructure and mechanical property of pulse electroplated coatings was discussed.

The Continuous Plating of Ni-Cr Composite Coatings and TiO<sub>2</sub> Nano-Modify

Ni-Cr films were electrodeposited from a nickel sulfate, chromium chloride and chromium sulfate bath. To avoid the poor adhesion and bad surface morphology of the secondary-co-deposition of Ni-Cr alloy films, H2O and DMF (volume ratio as 1:1) is used as solvent. Along with the alloy films growing thick, their surface apertures become larger correspondingly, which causes the hardness and corrosion resistance of the films becoming poor. For comparison, nanocrystalline Ni-Cr films with TiO2 nanoparticles were obtained on the same condition. TiO2 nanoparticles have an average size of 40 nm. The corrosion resistance of the Ni-Cr composite coatings were comparatively evaluated by salt spray test. It is found that the incorporation of TiO2 particles enhances the microhardness and corrosion resistance of the coatings. The reason is that the nano-TiO2 particles in the deposit effectively reduce the size of Ni and Cr crystals through grain refinement-strengthening and dispersion-strengthening effect. The observation results of scanning electron microscopy (SEM) indicated that the Ni-Cr films without dispersions of TiO2 nanoparticles exhibited numerous large and deep crackles, however, the crackles of nano-TiO2 Ni-Cr film distinctly became less.

Crystallization of titania ultra-fine particles from peroxotitanic acid in aqueous solution in the present of polymer and incorporation into poly(methyl methacylate) via dispersion in organic solvent

We report a novel strategy for incorporation of titanium dioxide (TiO2) particles, which were crystallized from peroxotitanic acid in the presence of hydrophilic polymer by hydrothermal treatment in aqueous solution, into poly(methyl methacrylate) (PMMA) via dispersion into chloroform. Dispersion of TiO2 particles into chloroform was achieved by solvent change from water to chloroform in aid of amphiphilic polymer dispersant, poly(N-vinyl pyrrolidone) (PVP), poly(N-vinyl pyrrolidone-co-methyl methacrylate) (PVP-co-PMMA), poly(N-vinyl pyrrolidone-block-methyl methacrylate) (PVP-b-PMMA) through azeotropical removal of water. Incorporation of TiO2 particles into PMMA was carried out by a casting process of a mixture of TiO2 particles dispersed with PVP154-b-PMMA156 in chloroform and PMMA on a glass substrate. Resultant hybrid film containing TiO2 less than 10 wt.% showed high transparency in visible region attributable to homogeneous dispersion into PMMA matrix. The refractive index of the hybrid films increased with TiO2 content and agreed with the calculated values.