Nano TiO2 Research Articles

Particle Formation Mechanism of TiCl4 Hydrolysis to Prepare Nano TiO2

This study utilizes Aspen Plus chemical process simulation software (V11), applies uniform nucleation theory and growth kinetics equations, and explores the particle formation mechanism of TiCl4 hydrolysis to prepare nano TiO2. In the water/ethanol system, the effects of the reaction time, reaction temperature, water addition, pH value, and ethanol amount on the crystal nucleation rate and TiO2 particle distribution (PSD) were studied in detail by adding triethanolamine dropwise and using the Aspen Plus chemical process software simulation calculation method. The calculation results indicate that at room temperature, the formation of TiO2 crystal nuclei mainly occurs in the first 300 s and then enters the growth stage. The reaction was carried out under neutral conditions at room temperature for 4 h in 1 mL TiCl4, 6 mL C6H15NO3, 15 mL H2O, and 30 mL C2H5OH. The maximum number of particles reached 195 mesh per cubic micrometer, and the particle size after crystal nucleus growth was smaller, with a D50 of 6.15 nm. The distribution curve shows a normal distribution, which is basically consistent with the experimental results. When studying various factors, it was found that controlling the reaction time within 60 min and maintaining the reaction temperature at room temperature can reduce the particle size D50 to 2.44 nm. Continuing to adjust the amount of water added, it was found that at 1 mL, D50 decreased again to 0.19 nm. Adjusting the pH value found that maintaining the neutrality did not change the particle size. Continuing to adjust ethanol, it was found that adding an appropriate amount of ethanol promoted nucleation and growth. At 4 mL, the maximum number of particles reached 199 mesh per cubic micrometer, but D50 slightly increased to 0.24 nm.

Novel technique of vibration minimization during hard machining

AbstractThis research paper explores the performance of electrorheological fluids, widely known as smart fluids, which are popular because they experience immediate changes in their characteristics when applied to exterior magnetic or electric field. On application of high voltage, the ER fluid alters its form to semisolid from viscous liquid within a few milliseconds, which is reversible. The reversible nature of ER fluid was employed to absorb vibrations during hard machining. In this research, the consequence of the application of electric field to the ER characteristics of numerous non‐Newtonian fluids with an accumulation of TiO2 and Al2O3 nano elements are investigated. The purpose of this research is to discover the ER sample, which has the highest viscosity, highest breakdown voltage, but less sedimentation. So the selected sample can be used in ER dampers for the purpose of shock absorption. The ER fluid behaves as a mainspring with nonlinear vibration features that are managed by an arrangement of ER fluid, the structure of plunger, and the constraints of applied electric field. In this research, we have employed steel metallic specimens made from EN24T of 302BHN and the machining experiments are conducted to attain the shape parameters that can reduce the tool vibration and help improve the process of cutting at the time of machining with minimum application of fluid utilizing hard metal inserts. In this work, cutting tool parameters were analyzed like cutting force, tool wear, tool vibration amplitude, and surface roughness. It was observed that ER damper has shown its better performance at 5KV. At 5KV, cutting force was the least, tool wear was the least, tool vibration amplitude was the least, and surface roughness was the least. The use of an ER fluid damper decreases tool vibrations and successfully enhances machining performance. The machining industry will be benefited with commercialization of this technique.

Review of the sol–gel method in preparing nano TiO2 for advanced oxidation process

Abstract Application of nano titanium dioxide (TiO2) in various fields such as advanced oxidation process (AOP) has led to the development of its preparation technologies. The sol–gel process is a widely used chemical wet method for preparing nanoscale TiO2 gels. This technique offers numerous advantages, such as the potential to produce large quantities of homogeneous materials with high purity, surface area, porosity, and reactivity, as well as being cost-effective, simple to implement, and capable of controlling the size and shape of the resulting particles. This review provides a comprehensive overview of the chemicals, reaction conditions, and procedures required for preparing nano TiO2 using the sol–gel method. It covers the selection of necessary compounds, such as TiO2 precursors, solvents, hydrolysis agents, and additives, along with their composition and sequences of adding, reaction order, and impact on the final product. Additionally, it provides detailed information on the routes of gel formation and ambient conditions, including temperature, humidity, stirring speed, injection rates of compounds, aging process, and storage conditions. This information serves as a basic reference for understanding the sol–gel process and the relative contribution rates of the influencing factors, which is essential for controlling the size, morphology, crystallinity, and other physicochemical properties of the resulting TiO2 gel/powder for targeted applications.

Viscoelastic and vibrational studies of nano hybrid fibre metal laminates

Employment of distinct fibres (glass/carbon etc.) in Fibre Metal Laminates (FMLs) is one way of enhancing the durable life of an FML and its performance under dynamic loads. In the present work, carbon fibre is employed in GLARE (Glass/Aluminium laminated epoxy) to enhance the vibration (natural frequency) and viscoelastic (storage modulus ( E′), loss modulus ( E″) and Tan δ) properties. Similarly, the influence of 1 wt% of Al2O3 (alumina), ZrO2 (zirconium oxide) and TiO2 (titanium oxide) nano particles are also studied in hybrid (carbon/glass) FML. The mean particle size of Al2O3 (5.1 nm), ZrO2 (25.3 nm) and TiO2 (63.2 nm) were estimated using the Scherer equation with the aid of X-ray diffractometer analysis. Hybridisation resulted in a 22%, 10% and 2% increase of natural frequencies from mode 1 to mode 3 and 36.3%, 15% and 13.2% of E′, E″ and Tanδ, respectively, when compared to GLARE (glass fibre reinforced aluminium laminated epoxy). TiO2-reinforced hybrid FML shows the highest natural frequencies among all nanohybrid FMLs. The results summarise that natural frequencies and viscoelastic properties of nanohybrid FMLs are sensitive to the type of fibre, nano particle reinforcement and its size. A stereo microscope and a scanning electron microscope (SEM) were used to analyse the defects at the interface and the nanoparticle dispersion in the matrix, respectively. Further, a numerical model was developed to perform free vibration analysis, and it was noticed that the results were similar to experimental values.

Preparation and Characterization of Nano TiO2–Hydroquinone-Doped Al Composites and Investigation of Theirs Wear Properties

Preparation and Characterization of Nano TiO2–Hydroquinone-Doped Al Composites and Investigation of Theirs Wear Properties

Oxygen vacancy boosting Fenton reaction in bone scaffold towards fighting bacterial infection

Bacterial infection is a major issue after artificial bone transplantation due to the absence of antibacterial function of bone scaffold, which seriously causes the transplant failure and even amputation in severe cases. In this study, oxygen vacancy (OV) defects Fe-doped TiO2 (OV-FeTiO2) nanoparticles were synthesized by nano TiO2 and Fe3O4 via high-energy ball milling, which was then incorporated into polycaprolactone/polyglycolic acid (PCLGA) biodegradable polymer matrix to construct composite bone scaffold with good antibacterial activities by selective laser sintering. The results indicated that OV defects were introduced into the core/shell-structured OV-FeTiO2 nanoparticles through multiple welding and breaking during the high-energy ball milling, which facilitated the adsorption of hydrogen peroxide (H2O2) in the bacterial infection microenvironment at the bone transplant site. The accumulated H2O2 could amplify the Fenton reaction efficiency to induce more hydroxyl radicals (·OH), thereby resulting in more bacterial deaths through ·OH-mediated oxidative damage. This antibacterial strategy had more effective broad-spectrum antibacterial properties against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). In addition, the PCLGA/OV-FeTiO2 scaffold possessed mechanical properties that match those of human cancellous bone and good biocompatibility including cell attachment, proliferation and osteogenic differentiation.

A Mini Review of Photocatalytic Effects of Nano TiO_2 and an Analysis of Their Effectiveness

A Mini Review of Photocatalytic Effects of Nano TiO_2 and an Analysis of Their Effectiveness

Comparative analysis of thermo-physical and mechanical properties of PALF/CF/epoxy resin with and without nano TiO2 filler

The performance of an engineering material depends on its potentiality and characterization under different mechanical and thermal test environments. The present research study has revealed the performance of a new class of hybrid composites, focused specially on the general trends observed in their impact of fabrication and its properties. To investigate how the mechanical and thermal qualities of the epoxy matrix may be improved, pineapple leaf fibre and carbon fibre were particularly chosen. By embedding the selected filler into the Pineapple leaf Fiber/Carbon Fiber(PALF/CF) reinforced epoxy resin, coordination effects, impact of embedding were achieved in the form of modified mechanical and thermal properties. The present research work is focused to perform the thermal and mechanical properties of pineapple leaf fiber/carbon fiber reinforced epoxy resin(ER) composites with and without particulate nano TiO2 fillers. The comparison of hybrid fibre (carbon and pineapple leaf fibre) reinforced epoxy composites with and without particulate nano TiO2 fillers was done. The results of the mechanical tests demonstrated that, in comparison to all other composites, the inclusion of nano fillers improved the tensile, flexural, and impact strengths. Nano particle reinforced with hybrid composite has a score of 23.4, whereas clean epoxy only gets a score of 4.5. It follows from this example that the presence of nanoparticles raises the residual values.

Coupled effect of the freeze-thaw cycles and salt erosion on the performance of concretes modified with nanoparticles

In cold and saline soil regions, freeze-thaw (F-T) cycles and salt erosion are two major factors determining the durability of concrete structures. This paper aims to investigate the influential mechanism and deterioration of the mechanical and microstructural properties for the concretes modified with nano-TiO2 (NT) and nano-SiO2 (NS) exposed to the coupled environment conditions of the F-T cycles and salt erosion. 180 F-T cycles were conducted on the concretes immersed in five kinds of environment media, namely, water (WF), air (AF), solution with a concentration of 5% Na2SO4 (SSF), solution with a concentration of 5% NaCl (SCF), and a mixture solution with the concentration of 5% Na2SO4 and 5% NaCl (HSF). The results indicate that the added nanoparticles and media significantly influence the overall performance of concrete samples. The SCF has the greatest influence on the degradation of concretes, following by the HSF, SSF, WF, and AF. Meanwhile, the compressive strength of concretes modified with NT is lower than that modified with NS. There is an optimal nanoparticles ratio for the nano-concrete samples to resist coupled effect of the F-T actions and salt erosion, and the optimal nanoparticles ratios for the concretes modified with NS and NT are 1% and 2%, respectively. Moreover, the filling effect on pore structure for the concretes modified with NS is better than that with NT, more hydration products and corrosion products occur on the concrete surfaces, and the crystals on the surface of concretes modified with NS are larger than that modified with NT. Furthermore, for the concretes modified with nanoparticles in the first 90 F-T actions, the gel micro-pores (<10 nm) increase, while the macro-pores (>5000 nm) decrease. However, the gel micro-pores decrease and the macro-pores increase within the 90–150 F-T cycles. This research would provide significant instructions on the exploration of the anti-erosion and frost-resistance of nano-concretes in marine and cold region engineering.

Compressive and Shear Strength of Kevlar based Nano Composites

The Fibre Reinforced Composite (FRC) material consists of building materials in macroscopic level by having fibres and resin as reinforcement and matrix material respectively. It has different physical and chemical properties that were bonded together in order to get new material with different required characteristics from individual components. The properties of the composites are largely depending on the matrix and reinforcement materials. The matrix strengthening process by introduction of fine nano particles in composite laminate was done in this work. In order to study the effect of nano particles, the composite consists of Kevlar- 49 (K49) fibre in woven form with epoxy resin as matrix was considered. All the test specimens have been prepared with 12 layers of K49 to build 3mm thickness using vacuum bag moulding method. The K49 fibre in form of plain-woven type were chosen as reinforcement material. The nano fillers such as Titanium dioxide (TiO2), Calcium Carbonate (CaCO3) and Graphite powder (Gr) were used as nanomaterial added in the matrix and was compared with pure K49 reinforced composites for better performance. The TiO2, CaCO3 and GR nano fillers were constituted on various weight ratios in FRC. The structural properties like compression and shear strengths were determined as per ASTM standards. The fracture behaviour for all the categories of laminate has been detailed and reported using scanning electron microscope.

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.

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.

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.

Influence of Various Nanomaterials on the Rheology and Hydration Kinetics of Oil Well Cement.

Nanomaterials have great potential to influence the properties of cement-based materials due to their small particle size and large specific surface area. The influences of Nano-SiO2 (NS), gamma-nano-Al2O3 (GNA), alpha-nano-Al2O3 (ANA), and nano-TiO2 (NT) on the rheology and hydration kinetics of class G cement at 30 °C were investigated in this study. The nanomaterials were added in dry powder form at dosages of 1, 2, 3, 5, and 7% by weight of cement (bwoc), and their dispersion was accomplished using polycarboxylate superplasticizer (PCE) at a dosage of 1.6% bwoc. PCE provides a uniform dispersion of nanoparticles in the cement matrix, enhancing the efficiency of nanomaterials. The w/c ratio varied between 0.718 and 0.78 to form a constant-density slurry of 1.65 g/cm3. Our test results showed that NS and GNA caused significant increases in the rheology of the cement slurry, with this effect increasing with dosage, while ANA and NT tended to reduce the rheology of the slurry. Compared to a well-suspended and well-dispersed cement slurry generated by the use of PCE and diutan gum, all nanomaterials can accelerate early hydration by reducing the induction time, with GNA having the strongest influence, while NS was the only nanomaterial that further increased the long-term hydration heat release at 7 days. The stronger effect of NS and GNA on the cement slurry properties can be attributed to their higher chemical reactivity. The dosage effect on total hydration extent was relatively strong for ANA, NT, and NS from 3% to 5% but weak for GNA in the range from 3% to 7%.

Green synthesis of a broad-spectrum UV-blocking bitumen modifier: Investigation of anti-aging performance and mechanism in bitumen

The popularization of inorganic nanomaterials doping, which serves as an effective method to improve the aging resistance of bitumen, is constrained by suboptimal lipophilicity and limited broad-spectrum UV absorption. To overcome this, we synthesized an environmentally-friendly, broad-spectrum UV-blocking nanocomposite by coating nano TiO2–ZnO (Nano-TZ) with sustainable lignin. TEM, T-IR, and photocatalytic activity test results indicate successful lignin coating on the Nano-TZ surface, with the optimal concentration being 15% (Nano-15L@TZ). Rheological test results demonstrated improved UV- and thermal-oxidative aging resistance of the Nano-15L@TZ-modified bitumen compared to those treated with uncoated nanomaterials. The synergistic modification mechanism of the Nano-15L@TZ composite was elucidated by combining the contact angle with UV–Vis and XPS VB tests. Nano-TZ exhibited broad-spectrum UV blocking properties that mitigated the UV aging of bitumen and lignin, while lignin effectively improved its compatibility with bitumen and captured radicals generated by Nano-TZ and aged bitumen.

Influence of Nano Additives on Performance, Combustion, and Emission Characteristics of Diesel Engine using Tamarind Oil Methyl Ester-Diesel Fuel Blends

Hazardous emissions majorly NOx and the poor performance of alternative fuels (biodiesel/its blends) are global concerns, as fossil fuel depletion and rising energy prices encourage researchers to rely on alternative energy sources with the addition of nano additives in the recent decade. The current experimental study investigates the performance, combustion, and emission characteristics of biodiesel-diesel mixtures dispersed with titanium dioxide (TiO2) as a fuel additive on a 1-cylinder diesel engine. TiO2 was dispersed in a Tamarind Oil Methyl Ester (TOME)-diesel blend (B20) in three concentrations of 40, 80, and 120 ppm via ultrasonication in the presence of QPAN80 surfactant to enhance the stability of the prepared fuel sample. A ratio of 1:4 TiO2:QPAN80 was found to produce the highest stability and homogeneity which is evidenced by the characterization of TiO2. The engine tests revealed that the greatest decrement in BSFC, CO, HC, and NOx was observed as 15.2%, 15.2%, 11.10%, and 9.06%, and the maximum BTE, HRR,and CP were improved by 9.76%, 50.32 J/degree, and 50.32 bar for the B20T80 blend correlated with B20 blend. Thus, the inclusion of TiO2 nano additives improved overall engine performance and decreased emissions of CI engines significantly.

Surface properties of nano‐TiO2 synthesized from two different TiO2 precursor sources by an alkaline hydrothermal process followed with a H2O2 treatment: Experiments combined with statistical analysis

AbstractOur research aimed to improve the surface properties of TiO2 for application in dye‐sensitized solar cells (DSC) by an alkaline hydrothermal process combined with H2O2 treatment. The effect of the TiO2 sources on the product quality was evaluated further by statistical analysis of the experimental data. The two commercial TiO2 precursors from Supelco (Merck – Germany) and BA‐100 (China) were used to produce nano TiO2 by the hydrothermal process in NaOH solution with two different concentrations of 5 M and 8 M at 150oC. The final products were characterized by XRD, FT‐IR, FE‐SEM, and chemical bonds on the TiO2 surface were particularly identified by XPS. The XPS data were then analyzed statistically by the K‐Means Clustering algorithm based on R software. The results showed that NaOH concentrations were directly involved with the formation of Ti─O; Ti─OH bonds and TiO2 morphology. The H2O2 treatment showed similar effects on TiO2 surface bonding but with less significant impacts than those of NaOH. In particular, the TiO2 reactant sources did not influence the structures, morphologies, and especially the surface properties of the products. Hence, a low‐cost TiO2 reactant should be selected in terms of economically effective products. The final TiO2 products were suitable for applications in DSC.

Adsorption of Azo Dye Onto TiO2 Nanoparticles Prepared by a Novel Green Method: Isotherm and Thermodynamic Study

The current study examined the use of Sansevieria plant leaves extract as an environmentally acceptable, inexpensive, and safe green approach for creating titanium dioxide nanoparticles (NPs). Batch studies have been used to test the particles' capacity to bind to the azo dye congo red (CR), which has been adsorbed from its aqueous solution. The effects of many factors, including the weight of TiO2 NPs, the contact duration to reach equilibrium, the concentration of CR, temperature, and pH, have been investigated. Both the Freundlich and Langmuir models were used to analyze experimental results. According to the high values of the Freundlich model's correlation coefficient R2, it is discovered that the adsorption of CR dye onto nano TiO2 is well-suited. The kinetics analysis for the adsorption trials proposed the pseudo-second-order. Thermodynamic data showed that the CR dye adsorption onto nano TiO2 is a physical process that happens spontaneously and endothermically with increasing unpredictability.

Characteristic studies on sustainable upgraded bio-oil produced using green TiO2/AlSBA-15 nano composite

The march towards electric vehicles have commenced, but still, this would be deadly to already existing vehicles. The research in bioliquid fuels is yet to be uncompromised and a proper fuel would be a head turner. This work focuses on the in-situ synthesis of composite material TiO2/AlSBA-15 (10%-60%) where nano TiO2 is made using organic reducing agent; lemon peel extract. The catalyst was characterized using XRD, BET, N2 sorption studies, SEM, EDX, and TEM analysis. SEM pictures displayed the uniform coating of TiO2 over SBA-15 and hence the catalyst is termed as core–shell model. Pyrolyzed used cooking oil (UCO) was further reformed by upgrading by prepared catalysts. TiO2/SBA-15––30% exhibited best activity than the precursor materials by converting 97.7% of UCO into 89.9% of condensable liquids, and the GC MS analysis of the fuel revealed the presence of 91.3% of gasoline range hydrocarbons. The NMR spectra showed the presence of alkyl groups, aromatic alkanes, iso & n-paraffins. The characteristics of the prepared bioliquid light fuel was studied to understand its features such as calorific value, flash & fire point, pour & cloud point. The biofuel produced showed remarkably high calorific value (48.7 MJ/Kg) and least viscosity (1.9 Cst).

Assesing the behaviour of particulate/nanoparticulate form of E171 (TiO2) food additive in colored chocolate candies before and after in vitro oral ingestion by spICP-MS, TEM and cellular in vitro models

Potential risk of nanoparticles present in food additives should be assessed. Although food-grade additive E171 (TiO2) has been banned by European Union due to the potential occurrence of nanometric TiO2, it is still present in stock products and permitted in other countries. TiO2 (nano)particles from the outer coating of colored chocolate candies were determined by TEM (Transmission Electron Microscopy), ICP-MS (Inductively Coupled Plasma Mass Spectrometry) and spICP-MS (Single-Particle-ICP-MS). Total titanium content was in the range of 1219 ± 83 µg g−1, except for brown and white candies. Percentage of TiO2 particles bellow 100 nm was under 25% regardless the color, with most frequent size between 120 and 160 nm. In vitro gastrointestinal assays reveal differences in bioaccessibility percentages between whole candy (14%) or aqueous extracts of the coating of candy (37%). More than 90% of bioaccessible titanium was found in particulate form. Caco-2 cells viability decreased around 65% after 24 h exposed to intestinal fraction.