Effect Of TiO2 Research Articles

Physio-chemical study of traditional lubricant SAE 20 W40 and virgin coconut oil using TiO2 nano-additives

The present work is intended to investigate the effect of nanoparticle on the properties of traditional lubricant SAE 20 W40 and an eco-friendly oil - Virgin Coconut Oil (VCO). Over the decade, researchers have shown an interest in the use of nano-fluids because of its undue advantages such as reliability, durability, and increase in machinery life. Nanolubricants with varied concentrations of titanium dioxide (TiO 2 ) nanoparticles with base engine oil SAE 20 W40 and VCO have been developed. The effects of TiO 2 nanoparticles on physio-chemical properties of engine oil SAE 20 W40 and VCO have been determined. This work provides a thoughtful requirement for developing the new nanolubricant with better physio-chemical properties. The physio-chemical study has been done for both SAE20W40 and eco-friendly oil (VCO) using TiO 2 nanoadditives. Results obtained from the experiments are analyzed and compared with the physical properties of base Virgin Coconut Oil (VCO).

Processing and characterization of TiO2 filled polymer composites

This paper reports on the research dealing with the processing and characterization of TiO 2 filled polymer composites. It also presents the test results in regard to the physical, mechanical and micro-structural characteristics of the epoxy and polypropylene composites filled with micro-sized TiO 2 particles. The effective thermal conductivity of polymer composites with uniformly distributed micro-sized particulates are estimated using a theoretical heat conduction model proposed previously by the authors and the correlation is validated for TiO 2 filled polymers through numerical analysis and experimentation. Some other important thermal characteristics, such as glass transition temperature (T g ) and coefficient of thermal expansion (CTE) of epoxy and polypropylene composites are also estimated. The effects of TiO 2 content on these properties of epoxy and polypropylene have been studied experimentally. The estimation of effective thermal conductivity of the composites using finite element method (FEM) and the proposed theoretical model is done and the results are validated by corresponding experimental results. The findings of this research suggest that incorporation of TiO 2 into epoxy and polypropylene leads to substantial improvement in thermal conductivity and glass transition temperature of the resins. At the same time, TiO 2 helps in lowering the coefficient of thermal expansion of such composites. This work further shows that the FEM serves as a good predictive tool for assessment of thermal conductivity of these composites. The theoretical correlation proposed in this work can serve as a very good empirical model for spherical inclusions to estimate the effective thermal conductivity of the composites within the percolation limit. With light weight and improved heat conduction capability, the TiO 2 filled polymer composites can be used for applications such as electronic packaging, encapsulations, communication devices, thermal interface material, printed circuit board substrates etc.

Effect of TiO2 and 11 minor elements on the reactivity of ground‐granulated blast‐furnace slag in blended cements

AbstractGround‐granulated blast‐furnace slags (GGBS) are glasses (>99%) of the CaO‐Al2O3‐SiO2 compositional system and are widely used as supplementary cementitious materials. Differences in reactivity of GGBS were screened by modifying the content of 12 minor elements (namely Ba, Ce, Cs, Cr, K, Mn, P, Sn, Sr, Ti, V, and Zr). Scanning electron microscopy observations showed that most elements entered the silicate glass matrix, only Sn was reduced to its metallic form and P accumulated in minor minerals. Mortar strength tests showed that 2 day compressive strength was reduced by >50% for a TiO2 content of 2.5 wt% in the slag. At 28 days the loss in compressive strength was still >40%. Calorimetric tests on other element additions showed that the content of network modifiers (Ba, Cs, K and Sr) and GGBS reactivity are positively correlated, whereas Ce, Cr, V, and Zr significantly decreased reactivity. Finally, it is shown that these effects can be estimated by the concentration and the weighted field strength of the added element.

Effect of TiO2 and TiN on the Viscosity, Fluidity, and Crystallization of Fluorine‐Free Mold Fluxes for Casting Ti‐Bearing Steels

TiN inclusions are known to exacerbate slag rimming and nozzle clogging during continuous casting of Ti‐bearing steels. Herein, the effect of TiO2 and TiN on the viscosity and fluidity of a fluorine‐free (F‐free) mold flux, as well as the corresponding precipitated crystalline phase is studied. Higher TiO2 is found to lower the viscosity and increase the strip length of the molten slag at TiO2 contents less than 10 wt%, whereas the viscosity increases suddenly and the strip length decreases rapidly at TiO2 contents above 10 wt%, due to the precipitation of CaTiO3 crystals, resulting in a solid–liquid coexisting melt. TiN has a low solubility in F‐free mold fluxes without MnO additions, and TiN is distributed in the molten slag as solid particles. TiN addition significantly increases the viscosity and shortens the strip length of the molten slag. On the other hand, F‐free mold fluxes containing MnO dissolves TiN into the molten slag through the oxidization of TiN to TiO2. However, beyond the solubility limit of TiN in fluorine‐free mold fluxes containing 5 wt% MnO, excess TiN is not completely dissolved. Then, the precipitation of Ca2Ti2O6 crystals is promoted.

Effects of TiO2 nanoparticles and electrodes surface-modified by low-temperature plasma on impulse breakdown voltage of propylene carbonate

Insulating and energy-storage materials, such as propylene carbonate, require high dielectric strength. To improve insulation performance of propylene carbonate, we surface treated a copper electrode with a low-temperature plasma based on liquid nanometer modification technology. Thus, a TiO 2 nano-modified liquid was prepared and the surface of the copper electrode was modified by sputtering a TiO 2 film. The surface morphologies of the electrode surface before and after modification and the impulse breakdown voltages and space charge distributions of pure and nano-modified propylene carbonate were studied. These results indicate that the TiO 2 film deposition on the surface of the copper electrode markedly reduced the surface roughness. Furthermore, after the surface modification, the breakdown voltage of pure propylene carbonate and nano-modified propylene carbonate increased by 9.4 and 14.3%, respectively. We analyzed the effects of the electrode surface modification and nanoparticles on the breakdown voltage of propylene carbonate from the perspective of space charge. The nanoparticles introduced shallow traps, which increased the rate of charge dissipation. Furthermore, surface modification of the electrodes inhibited charge injection into the liquid, which affected the generation and development of streamers in the liquid, thereby further improving the breakdown performance of the propylene carbonate.

Effect of TiO2-nanoparticles on copper toxicity to bacteria: role of bacterial surface.

The impact of titanium dioxide nanoparticles (nano-TiO2) on the aquatic environment is an important issue due to their increasing application. Although nano-TiO2 was reported to show an effect on heavy metal toxicity to aquatic organisms, the underlying mechanism is not well understood. In this study, two bacterial species (Bacillus thuringiensis (B. thuringiensis) and Bacillus megaterium (B. megaterium)) from sediment were selected to study the effects of nano-TiO2 on copper toxicity. Nano-TiO2 was found to inhibit the growth of B. thuringiensis and enhance the oxidative stress damage caused by copper, whereas these effects were not observed for B. megaterium. Transmission electron microscopy and flow cytometry showed that B. thuringiensis has stronger association ability to nano-TiO2 than B. megaterium. The existence of the S-layer on the surface of B. thuringiensis might be the possible reason, leading to the difference in copper toxicity. This indicates that the characteristics of bacterial surfaces might be important to the toxicity responses of nanoparticles.

Effect of TiO2 nanoparticles on DC breakdown performance of transformer oil-impregnated pressboard

Transformer oil-based nanofluid-impregnated pressboard (NIP) with TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanoparticles has been previously shown to exhibit substantially higher AC breakdown strength than that of pure oil-impregnated pressboard (OIP). In this study, OIP and NIP with TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanoparticles were prepared and experiments on DC breakdown strength of were performed. It was found that NIP possesses higher resistance to DC breakdown strength than that of OIP. To reveal the working mechanism, a pulsed electro acoustic (PEA) device was used to measure the space charge accumulation and dissipation characteristics in OIP and NIP. The results show that the density of deep level traps in NIP is visibly reduced owing to the addition of TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanoparticles and homopolar space charge accumulation on both sides of NIP is suppressed. Moreover, the charges injected from electrodes into NIP under DC voltage is also restrained owing to the increase of the Schottky potential barrier. Thus, the DC breakdown performance of NIP is considerably improved.

Symmetric electric double‐layer capacitor containing imidazolium ionic liquid‐based solid polymer electrolyte: Effect of TiO2 and ZnO nanoparticles on electrochemical behavior

ABSTRACTPoly(vinylidene fluoride‐co‐hexafluoropropene) (PVDF–HFP)‐based polymer electrolytes embedded with 1‐ethyl‐3‐methylimidazolium tetrafluoroborate ioniliquid have been synthesized to improve the ionic conductivity. Electric double‐layer capacitors (EDLC) have been prepared using the synthesized polymer electrolytes. Inorganic oxide fillers (5 wt %) such as titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles have been added to polymer electrolytes to compare the electrochemical behavior of the fabricated EDLC. The intrinsic dielectric constant of nanoparticles contributes in ionic dissociation which enhances ionic conductivity of electrolytes and also controls the specific capacitance of the EDLC fabricated with these electrolytes. Physicochemical properties of polymer nanocomposites have been investigated using X‐ray diffraction, differential scanning calorimetry, and Fourier transform infrared analysis, which confirms decrease of crystalline phase in host polymer PVDF–HFP. The maximum voltage stability is obtained for TiO2‐based polymer electrolyte. The high specific capacitance as well as high energy density is obtained for the EDLC cell with TiO2‐based polymer electrolyte compared to EDLC with ZnO nanoparticles‐based electrolyte. EDLC cells show specific capacitance of 76.4 and 44.51% of initial specific capacitance value at 2000th cycle for ZnO and TiO2‐based polymer electrolytes, respectively. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48757.

Features of the production and study of electrophysical characteristics (BeO + TiO2)-ceramics by impedance spectroscopy

The resulting electrically conductive two-component BeO ceramics with the addition of micro and nanocrystalline TiO 2 powder, which can be used as a material absorber of scattered microwave radiation in high-power electronic devices. The nature of the appearance of electrical conductivity and absorption of the microwave field in (BeO + TiO 2 )-ceramics has not been completely established. The impedance spectroscopy method was the first to investigate the electrical and dielectric characteristics of this ceramics in the frequency range from 100 Hz to 100 MHz, depending on the presence of a micro- and nanosized TiO 2 phase in the composition of BeO ceramics. It has been established that the static resistance of ceramics with the addition of a TiO 2 nanopowder is significantly reduced compared with the resistance of the original ceramics with TiO 2 micropowder. It is shown that the real and imaginary components of the dielectric constant of the studied ceramics increase to abnormally large values as the frequency of the effective electric field decreases, and in the high frequency range f ≥ 10 8 Hz, the process of dielectric relaxation begins, leading to an increase in the dielectric loss angle. The dielectric characteristics of ceramic samples are determined under blocking conditions for through conduction. The effect of TiO 2 micropowder additives on dielectric polarization processes with increasing frequency up to 12·10 9 Hz is considered. Ill. 8. Ref. 26.

Effect of TiO2addition on microstructure and mechanical properties of alumina‐based cores prepared by sol‐gel method

AbstractAlumina‐based ceramic cores have widespread applications especially in the investment casting of turbine blades due to chemical inertness with most of the superalloys, capability of machining in the green state, and their mechanical stability at high temperatures. The present work studied the effects of TiO2addition to the alumina‐based cores. These cores were prepared via the sol‐gel method process by mixing alumina powders with NH4Cl and silica sol. The effects of adding different amounts of titania from 5 to 30 wt% and different sintering procedures on mechanical, physical, thermal, chemical, and microstructural features of the bodies were investigated. According to the results of rheology measurements of the slurries and flexural strength of the green bodies, the suitable amount of solid loading was 45 vol. %. The results showed that there is an optimum content for TiO2addition. The specimen contained 15 wt. % titania and sintered at 1400°C for 2 hours had the thermal expansion coefficient as low as 4.8 × 10−6/°C (25‐900°C), suitable mechanical properties as a result of tialite formation, and apparent porosity of 28 vol. %, respectively. The result of creep deformation test showed that this specimen had near zero deformation at 1650°C.

Effect of TiO2 on Altering Direction of Interfacial Charge Transfer in a TiO2 -Ag-MPY-FePc System by SERS.

Interfacial charge transfer (CT) is of interest owing to its effect on the performance of molecular photovoltaic (PV) devices. The characteristics and structures of interfacial materials, such as TiO2 nanoparticles (NPs) in some solar cells, are employed to adjust the CT process. In this study, three kinds of interfacial systems, including a solar cell-like TiO2 -Ag- p-mercaptopyridine (MPY)- iron phthalocyanine (FePc) system, are compared to investigate the interfacial CT process using surface-enhanced Raman scattering (SERS) spectroscopy. The SERS results show the significance of TiO2 NPs in the system on altering the direction and path of the interfacial CT, which is closely associated with the CT enhancement contribution to SERS in such an interfacial system. SERS spectroscopy is expected to be a promising technique for the exploration and estimation of the interfacial CT behavior in PV devices, which may further extend the applications of SERS in the field of solar cells.

Effect of TiO2 on Altering Direction of Interfacial Charge Transfer in a TiO2‐Ag‐MPY‐FePc System by SERS

AbstractInterfacial charge transfer (CT) is of interest owing to its effect on the performance of molecular photovoltaic (PV) devices. The characteristics and structures of interfacial materials, such as TiO2 nanoparticles (NPs) in some solar cells, are employed to adjust the CT process. In this study, three kinds of interfacial systems, including a solar cell‐like TiO2‐Ag‐ p‐mercaptopyridine (MPY)‐ iron phthalocyanine (FePc) system, are compared to investigate the interfacial CT process using surface‐enhanced Raman scattering (SERS) spectroscopy. The SERS results show the significance of TiO2 NPs in the system on altering the direction and path of the interfacial CT, which is closely associated with the CT enhancement contribution to SERS in such an interfacial system. SERS spectroscopy is expected to be a promising technique for the exploration and estimation of the interfacial CT behavior in PV devices, which may further extend the applications of SERS in the field of solar cells.

Effect of TiO2 Surface Engineering on the Performance of Cobalt-Based Catalysts for Fischer–Tropsch Synthesis

A series of surface-modified TiO2 samples (Al-TiO2, Si-TiO2, and C-TiO2) with similar physical properties were synthesized. Comparison of the profound effect of different interfaces of the Co catalyst on the activity and stability in Fischer–Tropsch synthesis was investigated. Al2O3 or SiO2 nanoshell-modified TiO2 enhances the cobalt dispersion (Co/Al-TiO2) or reducibility (Co/Si-TiO2), which results in an increased cobalt-time-yield (CTY) of the catalysts. Hydrothermal carbon (HTC) shell modified TiO2 can simultaneously promote cobalt nanoparticle dispersion and reducibility. Accordingly, compared with the reference Co/TiO2 catalyst, the CTY and C5+ selectivity of Co/C-TiO2 is remarkably improved. Furthermore, the Co/C-TiO2 catalyst shows more stabilized activity under harsh FTS reaction conditions (230 °C, 1.0 MPa, CO conversion over 60%). This stable catalysis is attributed to the interfacial site (Co-TiO2), with the strength of the metal–support interaction resulting from the autoconsumption of the HTC layer during the reduction and reaction processes.

The effect of TiO2 nanotubes reinforcement on the mechanical properties and wear resistance of silica micro-filled dental composites

One of the most important aspects of dental resin composites is the ability to improve mechanical properties by adding reinforcing filler particles. TiO2 nanotubes are expected to improve the physical and mechanical properties of silica micro-filled dental composite. Therefore, TiO2 nanotubes were synthesized using an alkaline hydrothermal process and then functionalized with 3-methacryloxypropyl-trimethoxysilane. TiO2 nanotubes were characterized by scanning and transmission electron microscopies, X-ray diffraction and Fourier transform infrared spectroscopy. Different quantities of TiO2 nanotubes and silica microparticles were reinforced in bisphenol A-glycidyl methacrylate (Bis-GMA) and tri-ethylene glycol dimethacrylate to prepare dental composite samples. Thereafter, the flexural strength and modulus, compressive strength, degree of conversion of monomers, wear resistance and water sorption were utlized to examine the prepared composites. The flexural strength and wear resistance of composites with 3 wt% TiO2 nanotubes significantly increased in comparison with other composites. On the other hand, due to the stability of composite, the water sorption was decreased. Therefore, TiO2 nanotubes reinforcement could be a promising solution for the improvement of mechanical properties in dental composites.

Effect of TiO&lt;sub&gt;2&lt;/sub&gt; and MnO on Viscosity of Blast Furnace Slag and Thermodynamic Analysis

The effect of TiO and MnO on the viscous behavior and structure of CaO–SiO–MgO–AlO–TiO–MnO slags were studied using rotating cylinder method and FTIR spectroscopic analysis. Furthermore, the heat capacity and enthalpy change of the slag were calculated to clarify the influence of TiO and MnO on the heat quantity of the slag at elevated temperatures, and then the equilibrium temperatures and corresponding viscosities of the slag under various fixed heat quantities were also analyzed. The higher TiO and MnO contents resulted in lower viscosity. The FTIR results revealed that TiO and MnO depolymerized the slag by modifying the silicate network structure and breaking the linkage between the silicate and aluminate structure, while have little effect on aluminate structure of the slag. In the temperature range of interest, the enthalpy change of the slag increased with increasing TiO content, but remained basically unchanged with MnO additions. The fluctuations of the slag heat quantity had a significant influence on the slag temperature and viscosity. With the increase of TiO content, the equilibrium temperature of the slag at fixed heat quantity decreased and the corresponding viscosity increased. However, as the MnO content increased, the equilibrium temperature of the slag at fixed heat quantity was almost constant and the corresponding viscosity decreased.

The effect of TiO2 nanopigment on the optical properties of polyester fabric in UV–VIS–NIR regions

AbstractThe particle size parameter is a key factor that affects radiative properties of nanopigments, and consequently, pigments of the same type but different sizes represent different spectral performance. Therefore, current study dealt with a systematic experimental investigation on the effect of TiO2 pigmented coatings on spectral reflectance and color performance of white and colored polyester fabrics in UV, VIS, and NIR region of electromagnetic spectrum, with a special emphasis on VIS region. In order to accomplish this target, polyester fabrics were coated with TiO2 nanopigment with various concentrations and different diameters, and their reflectance spectra were measured using spectrophotometric method. Two‐way analysis of variance (ANOVA) was utilized to investigate the significance of the effect of TiO2 nanopigment on the color performance of coated fabrics. According to experimental observations, an organized color shift appears in color coordinate of fabrics coated with TiO2 nanopigment of various sizes. Moreover, although TiO2 nanopigment with 35 nm diameter has the most significant impact on short wavelength region (UV region), the effect of pigment with 250 nm diameter is more noticeable on NIR region as long wavelength region.

Effects of TiO2 crystallinity and oxygen composition on forming characteristics in Pt/TiO2/Pt resistive switching cells

“Forming” is a stage in resistive switching (RS) devices that occurs before switching and represents an important physical phenomenon in the universal operating mechanism of such devices. Forming in a resistance change material appears to be a kind of dielectric breakdown. In this study, we performed time-dependent forming (TDF) characterization of Pt/TiO2/Pt resistive switching cells with TiO2 layers of different crystallinities and oxygen compositions. We prepared two samples in which the grain boundary density and the density of oxygen vacancies differ, while both the TiO2 layers exhibited the similar crystal structures. Our results reveal that the Weibull slope and variation of time to forming are determined by the deposition method of the Pt bottom electrode (BE) films. Moreover, the initial cell resistance and distribution of the TDF characteristics depend not only on the crystallinity but also on the oxygen composition of the TiO2 layers. The variation of time to forming increases as the distribution of initial resistance is reduced in Pt/NiO/Pt resistive switching cells with different NiO crystallinities. Conversely, the variation of time to forming decreases as the distribution of the initial resistance is reduced in the case of the Pt/TiO2/Pt cells. These results reflect differences in both the grain boundary density (crystallinity) and the density of oxygen vacancies (oxygen composition) of resistance change materials used in the resistive switching cells. The clear difference of crystallinities and oxygen compositions might originate from differences in the oxide deposition mode during reactive sputtering.

Hybrid Effect of TiO&lt;sub&gt;2&lt;/sub&gt;/Reduced Graphene Oxide Based Composite for Photo-Catalytic Water Splitting and Strain Sensing

Solar Energy is an everlasting source of energy with minimal carbon footprint. However, due to lack of reliability and consistency it needs to be converted into more reliable and effective means that can be used to provide energy on demand. Hydrogen is a promising carrier and is thus an efficient mean of energy to be converted in, stored and transported. A more direct approach towards harnessing Solar Energy is by photo-aided generation of hydrogen via splitting of water using photolysis. Photocatalytic water splitting is therefore a promising method for future energy security. On the other hand strain sensing is a useful technique to measure medium range loads in trusses or tension rods &amp; can easily replace the existing fragile &amp; expensive semiconductor based sensors. This was done by using a composite of TiO2 /Reduced Graphene Oxide (RGO); TiO2 (anatase) was synthesized via sol-gel process and the main precursor was titanium tetrapropoxide (Ttip). Titania (anatase) characterized by XRD and photo spectrometry while Graphene oxide was synthesized via modified Hummer’s Method. The obtained Reduce Graphene Oxide was dispersed using Sodium Dodecyl Benzene (SDB) and Hydrazine Hydrate. A drastic synergetic effect was found by simply mixing RGO with TiO2 Solution. This not only broadened the photoactivity spectrum of TiO2 from UV region to the more available visible light radiation but also exhibit strain sensing properties and considerable tunable gauge factor. The photocatalytic effect of our composite was tested by coating it over Polycarbonate &amp; then analyzing emitted gas bubbles in a UV radiation chamber while strain sensing was done by coating it on an elastic substrate &amp; applying loads against values of resistance which were measured. This study will also include the reduction of recombination and band gap of TiO2 in order to synchronize it with the available Solar Spectrum thus maximizing solar-to-hydrogen efficiency.

Photocatalytic Properties and Graphene Oxide Additional Effects in TiO&lt;sub&gt;2&lt;/sub&gt;

Photocatalytic activity in TiO2 attract great attention because it promising application in contaminations on degradation and energy conversation. However there is a need on TiO2 band gap modification to be equivalent with the visible light. Thus, inviting several method of addition certain elements including in this study, the additional of graphene oxide (GO) was investigated. GO were prepared by Hummer method before it was added into TiO2. The formation of GO from it graphite precursor had been confirmed by Raman spectroscopy. The existence of D-band at wavelength of 1328 cm-1 and G-band at 1573 cm-1 shows the formation of GO. The GO was then added in different concentration; 0.0 - 1.0 wt% into TiO2. The photocatalytic activity was determined using calculating the photodegradation efficiencies of methylene blue under UV light irradiation. The experimental results showed that the photodegradation of MB were increased with higher dopants concentration due to reduction of band gap energy of TiO2 from 3.2 eV to 3.0 eV for 1.0 wt% GO-with the photodegradation efficiency of GO doped TiO2 was 61.38%.

Effect of TiO2 Nanoadditives on the Combustion Performance and Emission Characteristics of a DI Diesel Engine

Development of environmental friendly fuels is the ever constant endeavor in the field of engine technology. Owing to the merits of Diesel fuel, number of vehicles operated with Diesel are increased to meet the needs of multiplied population. However, depletion of fossil fuels and environmental pollution are the main concerns with the diesel engines. Usage of bio-fuel is found to be the prominent technology in compensating fossil fuels depletion, whereas emission control is a major setback. Suspension of nano particles in the conventional fuels termed as Nanofuel is the prominent technology in emission control. Hence, the present work is aimed to investigate the influence of TiO2 nano particulate in Diesel on the performance and emission characteristic of single cylinder Diesel engine. From the experimental results it is observed that the performance of the engine is marginally increased with the suspension of TiO2 nano particles whereas the reduction emissions are considerable.