Addition Of TiO2 Research Articles

The in-situ spinel formation in a magnesia alumina castable and the effect of selected additives on the properties of the castable

Four additives (a sodium polyphosphate, microsilica, titania and zirconia) were tested in a magnesia alumina castable to investigate their influence on the spinel formation at high temperatures. The impact of the additives is studied with respect to both the amount of spinel formed in the burned castable and the microstructure established by the spinalization.Dilatometric measurements conducted on the castables allowed to determine the onset temperature of the spinel formation, which was indicated by a strong increase of the linear thermal expansion. For phosphate-containing samples, the expansion associated with the spinelization occurred already ∼100 °C below the temperature at which the corresponding expansion was observed for the additive-free reference sample.Furthermore, by a heat-treatment of the castables at 1200 °C or 1500 °C, the phosphate-containing samples developed notably higher amounts of spinel than the reference sample. The phosphate addition in these samples also results in a remarkably larger increase of the sample volume during the heat treatment and comparatively lower mechanical strengths of the burned samples. The SiO2, TiO2, or ZrO2 additions influenced the physical properties of the castable in a substantially smaller degree than the addition of sodium phosphate, and they also exerted a smaller effect on the spinelization in the castable than the latter one.

Effect of TiO2 addition on the microstructure and electrical properties of Al2O3 ceramics

The resistivity of the dielectric layer material of a Johnsen–Rahbek (J–R) electrostatic chuck is generally between E8 and E12 Ω⋅cm, while that of pure alumina ceramic is more than E15 Ω⋅cm. Therefore, it is necessary to regulate the resistivity of the alumina ceramic for use as a dielectric layer material for a J–R-type electrostatic chuck. An electrostatic chuck requires a uniform and controllable surface temperature on the silicon wafer. Therefore, there is a certain requirement for the thermal conductivity of the dielectric layer.In this experiment, Al2O3 ceramics with different TiO2 contents (ranging from 0.08 to 3.6 wt%) were used as the research system and sintered at 1550 °C in a reducing sintering atmosphere. The obtained samples showed electrical resistivity from E9 to E14 Ω⋅cm and thermal conductivity from 26 to 37 W/m·K. The effects of Al2O3 ceramics with TiO2 on the phase composition, microstructure, relative density, electrical conductivity, and thermal conductivity were systematically studied, along with the relationship between the temperature and electrostatic adsorption force J–R and the resistivity of the sample. The addition of 1.2 wt% TiO2 gave the Al2O3 sample better overall performance; its relative density was up to 97.88 %, resistivity was reduced to 7.09 × 109 Ω cm, thermal conductivity was 27.211 W/m·K, and the electrostatic adsorption forces at 300 and 500 V/mm were up to 119 and 331 gf/cm2, respectively. The samples were primarily used as dielectric layers of the electrostatic chuck. By simulating the electrostatic adsorption between the dielectric layer and silicon wafer under an external voltage, the J–R force of stable adsorption between the electrostatic chuck and the silicon wafer was realised.

Effect of The Composition of TiO2 Additives on The Physical and Magnetic Properties Crystal Structure and Microstructure of BaFe12O19 Magnetic Ceramics

<p>In this research, the manufacture of barium hexaferrite (BaFe<sub>12</sub>O<sub>19</sub>) magnetic ceramics and the addition of titanium dioxide (TiO<sub>2</sub>) additives with variations of 0%: 0.3%: 0.6% and 0.9% used the powder metallurgical method. The characterization used in this study is the measurement of density, porosity, X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Vibrating Sample Magnetometer (VSM), and Impulse Magnetizer K-Series. Based on the results of density and porosity measurements, the highest values were 4.95 g/cm3 and 5.45%, respectively. XRD results showed the formation of a BaFe<sub>12</sub>O<sub>19</sub> phase with some impurities at 0% (Fe<sub>2</sub>O<sub>3</sub>), 0.3% and 0.9% (Ti<sub>6</sub>O<sub>11</sub>), and 0.6% (Ti<sub>4</sub>O<sub>7</sub>). The SEM results showed that the morphology of TiO<sub>2</sub>-BaFe<sub>12</sub>O<sub>19</sub> was quite homogeneous, and the size and cavity ranged from 0.5 – 1.5 μm and 0.25 – 0.9 μm, respectively. VSM results show Mr, Ms, Hc, and Bhmax values of 1,489 kG, 3,235 kG, 1,758 kOe, and Bhmax of 0,867 MGOe, respectively. The results of the Impulse Magnetizer K-Series show the maximum and lowest magnetic flux values of 272.65 gauss and 218.10 gauss at 0.6% and 0% variation, respectively.</p>

Development and evaluation of biodegradable starch-based films containing cellulose nanocrystals/titanium dioxide nanoparticles as an alternative for food packaging

Biodegradable starch-based films are an environmentally friendly solution to reduce the use of petroleum-derived polymers. Thus, this work aims to obtain corn starch films by incorporating 5% w/w of cellulose nanocrystals (CNC), different concentrations of titanium dioxide nanoparticles (TiO2) (0, 0.25, 0.5, 1, and 2% w/w), and 40% w/w of glycerol and sorbitol (plasticizers), in a 1:1 ratio. The films showed a high potential for UV-light barrier, with an increase of 307% incorporating only 2 wt% of TiO2 in relation to the film without incorporation of TiO2. The use of TiO2 increased the white pigmentation capacity of the samples and decreased the lower water solubility – a reduction of approximately 28% using 0.5 wt% TiO2 compared to the CNC control sample was observed. The incorporation of TiO2 nanoparticles increased the tensile strength by adding 1 wt% of TiO2 nanoparticles with 34% increase in the tensile strength of the film without incorporation of TiO2. The thermal stability of the films with 1 wt% TiO2 and 5 wt% CNC increased by 85°C. Thus, the addition of CNC and TiO2 enabled an improvement in the physical/thermal/chemical properties of the films, making them possible alternatives for use in food packaging.

The Role of TiO2 on ZnAl2O4 Spinel Prepared by Direct Coagulation Casting Method: Physico-mechanical, Optical, Structural and Antimicrobial Properties

This work represents the shaping of alumina–zinc oxide (AZ) samples with the direct coagulation casting method. The effect of zinc oxide (0, 10, 20, 30, and 40 wt%) and the firing temperatures on the phase composition, microstructure, physical properties, and mechanical properties of the AZ samples were studied. The effect of titanium oxide (2, 5, and 7 wt%) and the firing temperatures on the phase composition, microstructure, physical properties, and mechanical properties of the AZ sample with 40 wt% of zinc oxide were studied. Furthermore, the optical properties, magnetic properties, and antimicrobial activity were measured. The results indicate that the increase in zinc oxide enhances the formation of zinc aluminate, which has a gahnite phase. Moreover, increasing the zinc oxide increases the apparent porosity and decreases the grain size and bulk density at various firing temperatures. On the other hand, the addition of 5 wt% titanium oxide increases the bulk density to 3.5 g/cm3 compared to 1.72 g/cm3 with no titania. The apparent porosity and compressive strength reached 5% and 69.2 MPa after 5 wt% TiO2 addition; respectively, compared to 59% and 27.2 MPa with no titania addition. The prepared samples show promising optical band gap of 2.98–3.97 eV, a mixed magnetic behavior, and favorable antibacterial activity against E. coli, S. aureus, B. cereus strains.

Tuning the temperature coefficient of the resonant frequency of the AlPO4–BPO4–SiO2 ternaries with TiO2 addition and sintering atmosphere control

Microwave ceramics with low relative dielectric permittivities (εr), high-quality factors (Q×f values), and near-zero temperature coefficients of resonant frequency (τf) are strongly required for the 5 G and forthcoming 6 G wireless communication system. Effects of the TiO2 addition and atmosphere control on the microstructures and microwave dielectric properties of 0.05AlPO4-0.05BPO4-0.90SiO2 (5A5B90S) and 0.45AlPO4-0.45BPO4-0.10SiO2 (45A45B10S) ternaries were investigated in this paper to achieve the above objective. Adding TiO2 produced the TiP2O7 and/or (TiO)2P2O7 secondary phases in the 5A5B90S, and TiP2O7 in the 45A45B10S sintered bodies, respectively, which improved their sinterabilities. Near zero-τf value (τf∼ −2.0(8) ppm/°C) whilst retaining low εr (∼4.97(7)) and high Q×f value (54,000 ± 1619 GHz) could be attained for the 5A5B90S with the addition of 15 wt% TiO2. In contrast, both the Q×f and τf values deteriorated with the addition of TiO2 for the 45A45B10S. Sintering in the B2O3 protection atmosphere helps suppress the formation of TiP2O7 and/or (TiO)2P2O7 secondary phases for both samples, specifically in the surface layer of the sample, which increased the tunability of τf to be near zero. Combined good microwave dielectric properties with εr∼4.47(6)，Q×f ∼ 48000 ± 950 GHz，τf∼ − 2.1(8) ppm/°C; εr∼ 5.05(8)，Q×f ∼ 45,326 ± 900 GHz，τf∼ − 7.6 ± 1.2 ppm/°C could be attained for the 5A5B90S + 10 wt% TiO2 and 45A45B10S + 15 wt% TiO2 ceramics, respectively by sintering in B2O3 protection atmosphere.

Influence of TiO2 and Al2O3 Nanoparticles Addition on Thermal, Wettability and IMC Growth of Sn-3.0Ag-0.5Cu Lead-Free Solder at Different Reflow Temperature

This study investigated the influence of adding 0.50 wt% and 1.0 wt% titanium dioxide (TiO2) and aluminium oxide (Al2O3) nanoparticles on the properties of Sn3.0Ag0.5Cu (SAC305) lead-free solder alloy. In terms of thermal properties, SAC305 lead-free solder with or without addition of TiO2 and Al2O3 nanoparticles, the melting temperature is very similar and comparable. The wetting performance of the SAC305 nanocomposite solder was determined by the contact angle. The best contact angle recorded is 31.65° at reflow temperature of 250°C for 0.50 wt% addition of TiO2 and Al2O3 nanoparticles. The thickness of the IMC layer was observed using an Optical Microscope and measured. Results show that the thickness of the IMC layer decreased when TiO2 and Al2O3 nanoparticles were reinforced into the SAC305 solder system, which shows significant decrease when 0.50wt% of TiO2 and Al2O3 nanoparticles were added. However, beyond 0.50 wt% the thickness of IMC layer increases along with increasing reflow temperature. The results reveal that the adsorption effect of TiO2 and Al2O3 nanoparticles will restrict the growth of the IMC layer under controlled concentration of the nanoparticles and reflow temperature. The optimal parameters to enhance the performance of SAC305 solder by reinforcing TiO2 and Al2O3 nanoparticles are reflowed at 250°C at 0.50 wt% concentration of TiO2 and Al2O3 nanoparticles.

Effect of additives on densification of tabular alumina: A case of single additive doping and co-doping

The effect of doping and co-doping of oxide additives on sintering properties and microstructural features of tabular alumina is investigated. To examine the effects of single doping, 2 wt % of each of CaO, Fe2O3, SiO2 and TiO2 were added to tabular alumina fines and the samples were sintered at 1550 °C, 1600 °C and 1650 °C. Single oxide doped batches showed improved density except the samples doped with CaO. The phase analysis and microstructural results of CaO doped samples revealed the formation of calcium hexa-aluminate phases which resulted in poor density. The abnormality in grain-growth on addition of TiO2 was found to have a deteriorating effect on the strength of samples at 1650 °C despite of maximum densification. To observe the effects of co-doping of oxides, 1 wt % of each of CaO, Fe2O3, SiO2 and TiO2 were added to tabular alumina in unique combinations under same sintering conditions. Co-doping of oxides was found to be effective in property development of samples at higher sintering temperatures. The characteristics of secondary phases so formed influenced the properties of tabular alumina through liquid phase sintering, abnormal grain growth or decreasing the bulk density of samples. The strength value increases with temperature, more prominently for samples with liquid phase formation, but decreases for samples with abnormal grain growth and hexagonal shaped secondary phase formation.

Development of photocatalytic carbonation coating for concrete: Enhancement of air quality and sequestration of CO2

A new eco-friendly carbonation coating with a photocatalytic function was developed using dicalcium silicate (C2S) and nano TiO2, aiming to remove air pollution and enhance the durability of concrete at the same time. The photocatalytic performance, mechanical properties, and durability of the carbonated coatings incorporating different additions of TiO2 were evaluated, and the development of carbonation products and microstructure were investigated. The results show that the photocatalytic efficiency was increased linearly from 2518 μmol·m−2·h to 4392 μmol·m−2·h as the TiO2 doping amount was increased from 1% to 8%. In addition, the composition and microstructure analysis indicated that TiO2 not only improved the carbonation degree of C2S but also promoted the formation of metastable calcium carbonate, including aragonite, vaterite, and amorphous calcium carbonate, leading to a densified microstructure structure. At the same time, the improved carbonation process could capture up to 15.18% CO2 by mass. As a result, the bonding strength was improved from 3.29 MPa to 4.69 MPa after incorporating 8% TiO2, which is much higher than the conventional cement-based coating. Furthermore, the microhardness of the coating increased from 150 HV to 178 HV.

Influence of Titanium Dioxide (TiO2) Nanoparticles on Durability Properties of Lightweight Foamed Concrete

The worldwide construction industry has realized the need for lightweight building materials that are flexible, high-performance, and ecologically benign. Considering the need, it has been found that lightweight foamed concrete (LFC), a new revolutionary material, can be used to lower the overall weight of conventional concrete. In concrete, nanoparticles are used due to their beneficial effects, such as their tiny size of particles and high reactivity to improve concrete’s strength. Furthermore, LFC is quite porous due to which it becomes less effective. The LFC matrix can be made effective by including many nanoparticles to improve its strength. In the current body of information, the impact of nano titanium dioxide in LFC has not yet been studied. As a result, there is considerable confusion regarding the method by which the nano TiO2 might influence the LFC's durability properties. Therefore, the application of nano TiO2 in the LFC matrix is the main emphasis of this work. The goal was to determine how various nano TiO2 weight fractions (1%, 2%, 3%, 4%, and 5%) affect the durability characteristics of LFC, including setting time, drying shrinkage, porosity, and water absorption. The findings suggested that excellent water absorption, porosity, and drying shrinkage of LFC are made possible by the presence of a 3% weight fraction of nano TiO2 in LFC. The microstructural of LFC is changed by the addition of nano TiO2.

Dielectric properties of ZnNb2O6-ZnTiNb2O8 composites for microwave applications

In this study, the dielectric properties were evaluated in the microwave region for a ZnNb2O6 (ZNO) matrix with added TiO2. X-ray diffraction analysis demonstrated that the addition of TiO2 to ZNO led to formation of the ZnTiNb2O8 (ZTNO) phase. Evaluation of the dielectric properties in the microwave region for the ZNO-ZTNO ceramic composites showed that the permittivity (εr) ranged between 23.08 and 26.19 and the dielectric loss (tan δ) was 7.20 × 10−5 to 3.25 × 10−4. The temperature coefficient of resonant frequency (τf) ranged from −97.64 ppm °C−1 to −62.93 ppm °C−1, thereby demonstrating that adding TiO2 increased the τf value. The ZNO-ZTNO composites were evaluated as dielectric resonator antennas and their far-field parameters obtained based on numerical simulations indicated a gain between 4.69 and 5.60 dBi, bandwidth of 125.00–164.00 MHz, and efficiency above 98%. These results demonstrate that the ceramics investigated in this study have great potential for application in devices that operate in the C-band.

Tuning Redistribution of CuOx Nanoparticles on TiO2 Support.

Nanoparticles exhibit unique catalytic performance, depending on their nanoscale size. However, controlling the particle size of the supported catalysts is still challenging. Here, we present a method for tunable redistribution of CuOx nanoparticles on rutile TiO2 support by physically adding pristine TiO2. The redistribution is driven by the work function difference (WFD) between the TiO2 support and the TiO2 additive, both of which exhibit distinct values, as determined through Kelvin probe force microscopy and electron binding energy analysis. Addition of TiO2 with lower work function (rutile) promotes electron transfer toward the CuOx/TiO2 composite, resulting in nanoparticle aggregation, while addition of TiO2 with higher work function (anatase) results in smaller CuOx on TiO2. The increase in particle size and electron density of CuOx, driven by the addition of rutile TiO2, promoted the complete conversion of nitrobenzene (100%) within 5 h. This is 2.7 times that of dispersed and degraded CuOx driven by mixing with anatase TiO2 (36.9%).

The Theoretical Ballistic Performance of Alumina Ceramics and the Effect of Nano Oxides Addition Using Finite Element Analysis

The present investigation has turned on the effect of nano CuO and TiO2 as a dopant on ballistic performance of sintered alumina armours and its results are simulated using finite element analysis. The model was constructed on armor-backing plate (Al6061-T6) assembly with a steel made core and copper made outer jacketed bullet at high velocity (820 m/s) by Ansys workbench. The depth of penetration of bullet drastically reduces to 36.17% due to addition of 2 wt% nano CuO with respect to pure alumina. The same optimized effect shown by 1 wt% nano TiO2 is about 40.42%. The residual velocity of bullet gradually decreases with time and there is more reduction of residual velocity of 38% and 56.82% at 140 μs by addition of 2 wt% nano CuO and 1 wt% nano TiO2 respectively with respect to pure alumina. The alumina armours with 1 wt% nano TiO2 addition showed the best ballistic performance as compared to nano CuO.

Optical Properties of TiO2 Doped ZnO-PVA Nanocomposites

One of the materials with the greatest potential for use in flexible devices is semiconductor nanocomposite material. In this paper, we report the synthesis of ZnO-PVA-TiO2 nanocomposite to be applied as a flexible optical sensor device. The optical property of ZnO-PVA nanocomposite is improved by the addition of TiO2 in this work. The optical characteristics of the ZnO-PVA nanocomposite depend on the concentration of TiO2. Spin coating method was successfully used to synthesize ZnO-PVA-TiO2 with various TiO2 concentrations of 1%, 2%, and 3% w/v, respectively. The absorbance spectrum of ZnO-PVA-TiO2 nanocomposite changes with the addition of TiO2. The absorbance peaks of ZnO-PVA-TiO2 nanocomposites were shifting to a lower wavelength, resulting in increasing the nanocomposite band gap energy. According to this result, future applications of the flexible optical sensor are one of the potential devices based on this study.

Polyimide/titanium dioxide self-cleaning nano-hybrid films with high photocatalytic properties

Self-cleaning films are considered an emerging paradigm of environmentally functional materials. Enhancing the photocatalytic activities of self-cleaning film is a viable strategy for improving its antifouling characteristics. In this work, a polyimide/titanium dioxide (TiO2) film (PI/TiO2) film was developed by casting a mixture of polyamic acid solution and TiO2 hydrosol with a subsequent thermal imidization. TiO2 with a concentration of 1, 3, and 5 ​wt% was successfully incorporated into the PI matrix and was equally distributed in nanometer size in the PI/TiO2 nano-hybrid films. The addition of TiO2 into the film significantly improved its catalytic performance as indicated by the photocatalytic degradation of methylene blue and resazurin solution, suggesting a good self-cleaning property for antifouling applications. In addition, the thermal and mechanical stability of the PI film were improved with the addition of TiO2. After eight cycles, the PI-TiO2 films also demonstrated excellent cycling stability. This study introduces a novel self-cleaning film family composed of PI/TiO2 nano-hybrid film and emphasizes the engineering potential of photocatalytic materials in the context of self-cleaning film.

Exploration of coating alternatives for the protection of bare steel and brass in scientific-technical artefacts

The development of new alternatives for the protection of metallic heritage aims to improve the performance of the coatings used in recent decades. For this purpose, the performance of three novel or poorly explored coatings in this field of study has been evaluated: Owatrol Oil, TiO2-modified Paraloid B-72 and a hybrid of poly(2-ethyl-2-oxazoline), PEOX and poly(4-hydroxy styrene), PHS as a self-healing coating. These have been compared with coatings widely used in conservation such as: Paraloid B-72, Incralac and microcrystalline wax C80. The coatings were evaluated after accelerated ageing in terms of aesthetic changes (visual observation under stereomicroscope and colour measurements), protective ability (electrochemical impedance spectroscopy) and chemical stability (FTIR). After 500 h of exposure to Xenon-arc lamp, it was observed how the addition of TiO2 to Paraloid B-72 partially reduces photo-oxidation of the polymer, but at the same time harms the protective ability due to the appearance of defects. The self-healing coating is quite stable and can also regenerates superficial scratches of about 100 µm if subjected to 90% RH. On the other side, Owatrol demonstrated a very poor performance. These advantages and disadvantages in their use have been compared with those of B-72, Incralac and C80 microcrystalline wax, identifying in which cases their application for protection on scientific-technical artefacts may be feasible.

Enhanced Microwave Dielectric Properties of the Ba2TiSi2O8 Ceramic by the Addition of TiO2

Enhanced Microwave Dielectric Properties of the Ba2TiSi2O8 Ceramic by the Addition of TiO2

Effect of oxide additives on densification of terracotta

In this study, the effect of the addition of a few oxides (TiO2, Cr2O3, Fe2O3 CaCO3, and MnO2) on the sintering behaviour and sintered properties of a raw clay are reported. Static sintering study revealed that, except CaCO3, all remaining compositions showed similar values of firing shrinkage, which is greater than the control batch. Both TiO2 and MnO2 addition leads to lower open porosity at 1000 °C. Dynamic sintering studies at a heating rate of 5 °C.min−1 reveal that the onset of vitrification is in the following order: MnO2 > CaCO3 > control, TiO2 > Cr2O3, Fe2O3 and few oxides (TiO2, Cr2O3 and Fe2O3) improve the firing range and sintering compared to control composition. The terracotta body's flexural strength was influenced by porosity and chemistry. An overall negative linear correlation between flexural strength and open porosity was evident. The beneficial role of Cr2O3 and TiO2 over other oxides can also be clearly discerned. The lightness value (L*) of the terracotta body did increase only with TiO2 addition. A clear trend of change in chromacity components (a* and b*) was affected by oxide addition and firing temperature. The incorporation of Fe2O3 improved the characteristic red colour of the terracotta, along with other positive effects on the sintering of the terracotta body.

PAN/TiO2 Ultrafiltration Membrane for Enhanced BSA Removal and Antifouling Performance

Membrane separation has been widely utilized to eliminate pollutants from wastewater. Among them, a polyacrylonitrile (PAN) ultrafiltration (UF) membrane has presented outstanding stability, and distinguished chemical and thermal properties. However, UF membranes inevitably incur fouling issues during their operation procedure caused by contaminant adhesion on the membrane surface, which would restrict the operational efficiency and increase the maintenance cost. The conventional physical and chemical cleaning is not an effective technique to reduce the fouling due to the additional chemical addition and inevitable structure damage. Recently, UF membranes combined with photocatalytic materials are suggested to be a useful approach to conquer the membrane fouling issues. Herein, TiO2 nanoparticles were utilized to blend with a PAN casting solution for fabricating a composite UF membrane via a phase inversion method. With a certain TiO2 addition, the obtained membranes presented an enhancement of hydrophilicity, which could promote the water permeability and antifouling performance. The optimized M3 membrane prepared with 15.0 wt% PAN and 0.6 wt% TiO2 exhibited an excellent water permeability up to 207.0 L m−2 h−1 bar−1 with an outstanding 99.0% BSA rejection and superior antifouling property. In addition, the photocatalytic TiO2 nanoparticles endowed the M3 membrane with a remarkable self-cleaning ability under the UV irradiation. This facile construction method offered new insight to enhance the UF membrane separation performance with an enhanced antifouling ability.

Effect of TiO2 Additions on the Properties of Bioactive Granulated Materials of the TiO2–SiO2–P2O5/СаO(ZnO) System

Effect of TiO2 Additions on the Properties of Bioactive Granulated Materials of the TiO2–SiO2–P2O5/СаO(ZnO) System