Addition Of nano-TiO2 Research Articles

Impact of nano-TiO2 on white Portland cement mortars: a combined XRD coupled rietveld, crystallographic and microstructural analysis

The present study investigated the structural, microstructural, and crystallographic changes associated with the addition of nano-TiO2 (NT) by intermixing and surface coating on freshly cast and hardened coatings on white Portland cement matrix samples at minimal dosages. Scanning electron microscopy (SEM) and VESTA were employed to analyze the microstructure morphology of the hydration products and the crystal structure parameters of the NT-modified white Portland cement mortar. Additionally, Rietveld refinement analysis was performed to quantify the crystal phases coupled with XRD using Xpert High Score Plus and Expo-2014 software. The Rietveld refinement analysis of the hardened coating surface followed by the fresh cast coating resulted in the most refined structural model compared with that of the intermixed and reference samples. The integration of NT also reduced the bond distances and polyhedral volumes, indicating denser atomic packing and enhanced interactions between the smaller NT particles and the white Portland cement matrix and enhancing the structural integrity within the matrix. Furthermore, SEM micrographs revealed a compact microstructure with enhanced CSH and reduced CH crystals in the NT-modified white cement mortar samples. The presence of hydration products and corresponding bonds were confirmed by Fourier Transform Infrared Spectroscopy.

Synergistic effects of nano titanium dioxide and waste glass powder on the mechanical and durability properties of concrete

This study investigates the combined use of waste glass powder and nano titanium dioxide (TiO2) on the mechanical and durability properties of the concrete. Waste glass being one of the major municipal wastes going into the landfill sites can be used as a pozzolanic material in the concrete, in this study cement is replaced with waste glass powder by 10% along with nano TiO2, it is used as an addition to cementitious material by 0.5%, 1% and 1.5%. Fresh and mechanical properties like setting time, workability, compressive strength and flexural strength is evaluated along with durability properties such as sorptivity, acid, sulphate and chloride attacks, elevated temperature test. Scanning electron microscope is done to understand the morphology of the blended concrete. Combined use of glass powder and nano TiO2 is found beneficial in mechanical and durability parameters whereas addition of nano TiO2 has resulted in decreased workability of the concrete.

A novel inorganic phosphate-based adhesive for bonding archaeological pottery: a preliminary exploration

Damage and fracture of archaeological potteries not only jeopardize the long-term preservation but also hinder their exhibition. To repair these pottery sherds effectively, this study introduces a novel inorganic phosphate-based adhesive and evaluates its effectiveness through a series of experiments. To determine the optimal base adhesive, the paper investigates the influence of varying weight ratios of the H2O–H3PO4 system and the Al(OH)3–H3PO4 system on properties including tensile lap-shear strength, microstructure, high-temperature resistance and phase composition. However, the original black color of the traditional CuO–phosphate adhesive limits its application. The innovation of this study lies in the addition of nano-TiO2 to the adhesive, which not only improves the bonding strength but also adjusts the color of the adhesive. This study has defined the optimal formulation (i.e., base adhesive = m[Al(OH)3]:m[H3PO4] = 7:100, filler = 10wt% nano-TiO2), and the final product shows no residual acid in adhesives. Additionally, the fracture surfaces are successfully bonded with a high strength of 3.56 MPa. Various ageing tests including dry-thermal ageing, hygrothermal ageing and UV irradiation ageing are conducted to assess the ageing resistance of the inorganic phosphate-based adhesive. The results indicate strong tolerance of adhesive to high temperature and high humidity environment. Preliminary applications in archaeological pottery restoration suggest that the inorganic phosphate-based adhesive offers considerable promise for repairing shattered pottery.Graphical

Effect of nano-TiO2 on physical and rheological properties of asphalt cement

Abstract In recent years, nano-modified asphalt has gained significant attraction from researchers in the design of asphalt pavement fields. The recently discovered Titanium dioxide nanoparticles (TiO2) are among the most exciting and promising nanomaterials. This study examines the effect of 1, 3, 5, and 7% of nano-TiO2 by weight of asphalt on some of its rheological and hardened properties. The experimental study included physical and rheological properties. The asphalt penetration, softening point, ductility, and rotational viscometer tests indicate that 5% nano-TiO2 is the ideal amount to be added to bitumen as a modifier. The study of the rotating viscosity test showed that the addition of nano-TiO2 helped to increase viscosity and lessen bituminous sensitivity. Rutting factor in terms of G*/sin δ indicated the addition of 3 to 7% of nano-TiO2 increased the rutting resistance of asphalt against higher temperatures and promoted performance grade by about one grade at 3% and two grades at a range of 5–7% this suggests that nano-TiO2 increased the stiffness of the asphalt and leading to enhance the rutting performance of asphalt. While fatigue parameter, G*.sin δ shows that as nanocontent increases, higher stiffness at 5 and 7% of TiO2 content leads to an increase in complex modulus and a decrease in fatigue parameter. Higher creep stiffness and higher m-values were noted at low temperatures as nano increases in asphalt binder, increasing stiffness and decreasing the m-value at −6 and 12°C. As a result, using 5% nano-TiO2 will improve asphalt’s physical properties and enhance asphalt anit-rutting and fatigue resistance.

Fabrication of carbon pasta elektroda composition modified with nanobentonite and nano TiO2 for niacinamide detection sensor

Niacinamide is the amide form of vitamin B3, which is usually analyzed for concentration using UV-Vis Spectrophotometry, HPLC, and KLT. The development of niacinamide analysis methods using cyclic voltammetry has not been widely studied. The use of working electrodes in cyclic voltammetry is usually carbon paste electrodes. However, these electrodes have disadvantages, relatively low sensitivity and slower electron transfer kinetics, so it is necessary to research working electrode modification to increase electrode sensitivity. This study aims to determine the effect of the addition of nanobentonite and nano TiO2 on carbon paste electrodes in improving electron transfer and electrode sensitivity in the analysis of niacinamide by cyclic voltammetry. Variations in electrode composition were conducted to determine the optimum composition in measuring niacinamide solution and the optimum pH in measuring niacinamide. Nanobentonite obtained from the synthesis using the sonochemical method produces an average particle size of 46.9 nm, and the composition of carbon, paraffin, nanobentonite, and nano TiO2 electrodes with a variation of 3:2:3:2 b/v has the highest current peak. The better the conductivity of the working electrode, the greater the maximum current peak produced due to the easy transfer of electrons for the reduction and oxidation reaction process. Using a buffer solution to adjust the pH of the niacinamide solution affects the analysis process, as evidenced by the IpA value at pH 7. The effect of pH variation also affects the stability of existing ions. So that the resulting current is higher, the higher the peak current value produced indicates, the more sensitive the electrode is due to high electron transfer. It maximizes the analysis of the concentration of the test solution because the measured concentration is linear with the measured current.

Enhancing the carbonation and chloride resistance of concrete by nano-modified eco-friendly water-based organic coatings

To effectively improve the carbonation and chloride resistance of concrete with eco-friendly waterborne organic coatings, two nanomaterials (i.e., nano-SiO2 and nano-TiO2) were utilized to modify the water-based polyurethane and epoxy resin paints at dosages of 1 wt%, 2 wt%, and 3 wt%, and the coated concrete specimens were fabricated. Then, accelerated aging experiments of ultraviolet irradiation were conducted on the coated concrete specimens, followed by accelerated carbonation or Coulomb electric flux experiments. In addition, partial coating film samples were analyzed by scanning electron microscopy and Fourier transform infrared spectroscopy. Results show that the application of water-based organic coatings can substantially improve the carbonation and chloride resistance of concrete. The two-component water-based epoxy resin coating exhibited a higher quality than the one-component water-based polyurethane coating, thus resulting in better improvement of the carbonation and chloride resistance of concrete. However, the anti-aging capability of water-based epoxy resin coating is lower than that of water-based polyurethane coating, resulting in the rapid decline of the carbonation or chloride resistance of coated concrete after ultraviolet aging. The addition of nano-SiO2 or nano-TiO2 to the water-based organic coating can reduce the defects in the coating, effectively improve the density of the coating, and further improve the carbonation and chloride resistance of the coated concrete, with average improvement ranges of 51–74 % and 24–27 %, respectively. Meanwhile, the addition of nano-SiO2 or nano-TiO2 can help reduce the damage of water-based coatings caused by ultraviolet irradiation, thereby improving the long-term carbonation and chloride resistance of coated concrete, among which the improvement effect of nano-TiO2 is higher than that of nano-SiO2.

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.

Nano-gelcoat application of glass fiber reinforced polymer composites for marine application: Structural, mechanical, and thermal analysis

To address the critical issue of environmental sustainability, the application of nano-gelcoat has emerged as a promising approach to extend the service life and enhance the durability of glass fiber-reinforced polymer composites (GFRPs), thereby protecting the marine environment. Despite the extensive use of GFRPs in marine structures, their performance is significantly influenced by marine environmental factors. However, despite its potential, there is a lack of research on the experimental application of nano-gelcoat. To fully understand the underlying mechanisms and optimize the performance of nano-gelcoat application, more experimental investigations are required. In the present study, the hydrothermal aging of nano-gelcoat-coated glass fiber-reinforced polymer composites was investigated. Nano TiO2 and nanoclay were used to enhance the performance of gelcoat. A three-month hydrothermal aging experiment was carried out in artificial seawater heated to 80 °C. Mechanical and water absorption properties of GFRPs and thermal, morphological and FTIR (Fourier transform infrared spectroscopy) properties of nano-gelcoat were investigated. An ANOVA analysis was performed to establish if the experimental results were statistically significant. The long-term aging tests showed that the addition of nano-TiO2 improved water resistance and maintained the mechanical properties of the composite. It also improved the melting point.

Effect of nano TiO2 and SiO2 on gelation performance of HPAM/PEI gels for high-temperature reservoir conformance improvement

Nanoparticles have been widely used in polymer gel systems in recent years to improve gelation performance under high-temperature reservoir conditions. However, different types of nanoparticles have different effects on their gelation performance, which has been little researched. In this study, the high-temperature gelation performance, chemical structure, and microstructure of polymer gels prepared from two nanomaterials (i.e., nano-SiO2 and nano-TiO2) were measured. The conventional HPAM/PEI polymer gel system was employed as the control sample. Results showed that the addition of nano-TiO2 could significantly enhance the gel strength of HPAM/PEI gel at 80 °C. The gel strength of the enhanced HPAM/PEI gel with 0.1 wt% nano-TiO2 could reach grade I. The system also had excellent high-temperature stability at 150 °C. The enhanced HPAM/PEI gel with 0.02 wt% nano-TiO2 reached the maximum gel strength at 150 °C with a storage modulus (G′) of 15 Pa, which can meet the need for efficient plugging. However, the nano-SiO2 enhanced HPAM/PEI polymer gel system showed weaker gel strength than that with nano-TiO2 at both 80 and 150 °C with G′ lower than 5 Pa. Microstructures showed that the nano-TiO2 enhanced HPAM/PEI gel had denser three-dimensional (3D) mesh structures, which makes the nano-TiO2 enhanced HPAM/PEI gel more firmly bound to water. The FT-IR results also confirmed that the chemical structure of the nano-TiO2 enhanced HPAM/PEI gel was more thermally stable than nano-SiO2 since there was a large amount of –OH groups on the structure surface. Therefore, nano-TiO2 was more suitable as the reinforcing material for HPAM/PEI gels for high-temperature petroleum reservoir conformance improvement.

Preparation and Application of Active Bionanocomposite Films Based on Sago Starch Reinforced with a Combination of TiO2 Nanoparticles and Penganum harmala Extract for Preserving Chicken Fillets.

The aim of this study was to develop sago starch-based bionanocomposite films containing TiO2 nanoparticles and Penganum harmala extract (PE) to increase the shelf life of chicken fillets. First, sago starch films containing different levels of TiO2 nanoparticles (1, 3, and 5%) and PE (5, 10, and 15%) were prepared. The barrier properties and antibacterial activity of the films against different bacteria strains were investigated. Then, the produced films were used for the chicken fillets packaging, and the physicochemical and antimicrobial properties of fillets were estimated during 12-day storage at 4 °C. The results showed that the addition of nano TiO2 and PE in the films increased the antibacterial activity against gram-positive (S. aureus) higher than gram-negative (E. coli) bacteria. The water vapor permeability of the films decreased from 2.9 to 1.26 (×10-11 g/m·s·Pa) by incorporating both PE and nano TiO2. Synergistic effects of PE and nano TiO2 significantly decreased the oxygen permeability of the sago starch films from 8.17 to 4.44 (cc.mil/m2·day). Application results of bionanocomposite films for chicken fillet storage at 4 °C for 12 days demonstrated that the films have great potential to increase the shelf life of fillets. The total volatile basic nitrogen (TVB-N) of chicken fillets increased from 7.34 to 35.28 after 12 days, whereas samples coated with bionanocomposite films increased from 7.34 to 16.4. For other physicochemical and microbiological properties of chicken fillets, similar improvement was observed during cold storage. It means that the bionanocomposite films could successfully improve the shelf life of the chicken fillets by at least eight days compared to the control sample.

Scaling Risk Index of Concretes Containing Nano-TiO2 and Supplementary Cementitious Materials

This paper presents a novel approach for assessment of scaling resistance of concretes with variable compositions (i.e., with and without addition of nano-TiO2 as well as with and without addition of fly ash and slag cement). The proposed approach is based on correlations between the data from thermogravimetric analysis of hydrated pastes and the results from actual scaling resistance tests. The results of the traditional (i.e., following the ASTM C672-03 method) scaling resistance test revealed that the effect of nano-TiO2 on the scaling resistance of concrete depended on the composition of the cementitious binder system (i.e., it was observed to change depending on whether the binder system contained or did not contain supplementary cementitious materials [SCMs]). While the use of nano-TiO2 improved the strength regardless of the type of concrete (i.e., it was effective in both plain concretes and in concretes with SCMs), the effect of nano-TiO2 addition on the scaling resistance was affected by the type of binder used in the mixture. The proposed scaling risk index correlated well with the actual scaling resistance test data (obtained from the ASCTM C672-03 test) from ordinary Portland cement and fly ash concretes with different mixture proportions and cured at different temperatures before the test.

Curing Behavior of UV-Initiated Surface-Modified Nano-TiO2/Epoxy Resin Prepolymers and the Properties of Cured Composites.

Nano-titanium dioxides (nano-TiO2) surface modified with isopropyl tri(dioctylpyrophosphate) titanate (NDZ-201), a titanate coupling agent, and 3-glycidoxypropyltrimethoxysilane (KH-560), a silane coupling agent, were separately mixed with bisphenol A epoxy resin (DEGBA) prepolymer and then cured using a UV-normal temperature synergistic curing process. Then, the isothermal curing process of the system was investigated by differential scanning calorimetry (DSC). The relationship between the organization structures, mechanical properties, and heat resistance properties of the cured composites and material formulation was studied, and the DSC results showed that the addition of nano-TiO2 reduced the curing reaction rate constant k1 and increased the k2 of the prepolymer, while the activation energy of the curing reaction after UV irradiation Ea1 decreased, and the activation energy in the middle and later periods Ea2 increased. The characterization results of the composite material showed that nano-TiO2 as a scattering agent reduced the photoinitiation efficiency of UV light, and due to its obvious agglomeration tendency in the epoxy resin, the mechanical properties of the composite material were poor. The dispersibility of the coupling-agent-modified nano-TiO2 in the epoxy resin was greatly enhanced, and the mechanical and heat resistance properties of the composite material improved remarkably. The comparison results of the two coupling agents showed that NDZ-201 had better performance in increasing the impact strength by 6.8% (minimum value, the same below) and the maximum thermal decomposition rate temperature by 4.88 °C of the composite, while KH-560 improved the tensile strength by 7.3% and the glass transition temperature (Tg) by 3.34 °C of the composite.

Microstructure, mechanical properties and tribological behavior of Cu-nano TiO2-MWCNTs composite sintered materials

The paper presents the results of microstructure, mechanical and tribological tests of copper matrix sinters with the addition of nano-TiO2 and copper-decorated multi-walled carbon nanotubes. A powder metallurgy was used for the production of composite materials. The aim of the work was to determine the properties and wear mechanism of the produced sinters with single additives and to investigate the synergistic interaction of titanium dioxide and carbon nanotubes. Wear tests were carried out using the pin-on-disc method at room temperature and 600 °C. Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Raman Microscopy, Thermogravimetric Analysis (TGA), Dilatometry (DIL), X-Ray Diffraction (XRD), and profilometer were used for the research. Moreover, the stiffness and hardness of the sinters were examined. The main wear mechanisms of the friction pairs tested at room temperature and 600 °C were adhesive, abrasive, and oxidation wear. Furthermore, at the test temperature of 600 °C, the formation of a tribofilm was observed on the surface of the friction pairs, which reduced friction wear. The introduced additions to the copper matrix increased its hardness, stiffness, work of axial deformation, and wear resistance. Moreover, additions decreased the relative value of the thermal expansion coefficient of the sintered copper. The friction pair no. 2 (Cu + 1 wt % MWCNTs – Inconel®625) was characterized by the lowest coefficient of friction at room temperature and 600 °C, of approximately 0.62 and 0.56, respectively. The sintered composite material of Cu – 10 wt% nano TiO2 – 1 wt%. MWCNTs was characterized by the highest mechanical properties and the lowest wear.

Photocatalysis enhanced constructed wetlands effectively remove antibiotic resistance genes from domestic wastewater

Antibiotic resistance genes (ARGs) is a new class of environmental pollutants that endanger both humans and the environment. So far, removing ARGs economically and efficiently has remained a challenge. In this study, combining photocatalytic technology with constructed wetlands (CWs) were used to remove ARGs, which can remove both intracellular and extracellular ARGs and reduce the risk of resistance gene spread. This study includes three devices: a series photocatalytic treatment-constructed wetland (S-PT-CW), a built photocatalytic treatment into a constructed wetland (B-PT-CW), and a single constructed wetland (S-CW). Results demonstrated that photocatalysis and CWs together increased the efficiency of removing ARGs, particularly intracellular ARGs (iARGs). The log values of iARGs removal ranged from 1.27 to 1.72, while the log values of eARGs removal were only 0.23–0.65. The iARG removal effectiveness was ranked as B-PT-CW > S-PT-CW > S-CW, and the removal effectiveness for extracellular ARGs (eARGs) was ranked as S-PT-CW > B-PT-CW > S-CW. Further investigation into the removal mechanisms of S-PT-CW and B-PT-CW revealed that CWs represented primary pathways for iARG removal, whereas photocatalysis was the primary pathways for eARG removal. The addition of nano-TiO2 altered the diversity and structure of the microorganisms in CWs, leading to an increase in the abundance of nitrogen and phosphorus removal microorganisms. The main potential hosts for target ARGs (sul1, sul2 and tetQ), were the genera Vibrio, Gluconobacter, Streptococcus, Fusobacterium, and Halomonas; the removal of these potential hosts from wastewater may result from their decreased abundance.

Effect on workability and compressive strength of M40 grade of concrete by partial replacement of cement by Nano Tio2

TiO2 is one of the most often used pigment ingredients in paints due to its many benefits. TiO2 can be used as a filler material in concrete to fill in cracks, voids, fissures, bleeding channels, and other gaps, hence increasing the concrete's strength. The goal of the current work is to examine how well M40 grade high strength concrete performs when nanomaterials are used. This has been done by partially substituting nano titanium dioxide (tio2) for cement (varying from 0.5% to 2%). By performing the slump cone test and the compaction factor test, it was possible to compare the workability of M40 grade concrete with and without the addition of nano tio2. Finally, compression, split tensile, and flexural tests have been used to assess the strength properties of both types of concrete.

Composite cathode for Li-sulfur system: Effect of inorganic additives on electrochemical performance

The influence of five different inorganic additives with different composition and morphology, viz. nanofibrous rutile/TiOxNy, Li4Ti5O12 (LTS) from Altair, TiO2-P90 from Evonik, TiOxNy-anatase and nano-TiO2 on the electrochemical performance of the activated carbon/sulfur composite cathode is evaluated by cyclic voltammetry at the scan rate of 0.1 mV s-1 and by galvanostatic chronopotentiometry at the 0.1 C rate. The composites are prepared by facile mechanical mixing of activated carbon with the inorganic additive and subsequent melting-diffusion with sulfur. The addition of nano-TiO2 from titanium isopropoxide, TiOxNy-anatase, rutile/TiOxNy, and LTS Altair to the carbon/sulfur composite cathode increased the charge capacity of the corresponding Li-sulfur cell. The negative effect of the P90 additive can be attributed to the blocking of its surface by Al2O3 and SiO2, hindering the adsorption of polysulfides. TiOxNy-anatase additive exhibits the highest capacity improvement due to its surface-enhanced redox chemistry of conductive and sulphiphilic surface resulting in a 7 % increase of the voltammetric charge capacity. In addition, this additive has a beneficial effect on the cycling stability of the sulfur composite cathode during galvanostatic cycling.

Effect of nano-TiO2 addition on the microstructure and erosion-corrosion behavior of Ti(C,N)-based cermets fabricated by in-situ carbothermal reduction

Ti(C,N)-based cermets with partially adding nano-TiO2 powders were fabricated via in-situ carbothermal reduction. The effects of nano-TiO2 additions on the microstructure, mechanical properties and erosion–corrosion resistance of the cermets were studied. The microstructure of the cermets principally consisted of white-core grains and those with non-typical core-rim phase. Furthermore, the addition of nano-TiO2 could refine the grain size. The comprehensive mechanical properties decreased and then increased with the substitution of nano-TiO2 particles. The influences of various nano-TiO2 contents on the erosion-corrosion resistance were analyzed in acid solution. Erosion-corrosion resulted in the loss of the nickel binder and the exfoliation of grains. The surface corrosion morphology indicated that the erosion-corrosion resistance of Ti(C,N)-based cermets was strengthened by adding nano-TiO2. Overall, the cermet with complete addition of nano-TiO2 showed the significantly improved comprehensive mechanical properties and superior erosion–corrosion resistance.

Effect of different sizes of Nano-TiO2 on wear resistances and surface hardness of resinbased dental composites

Objective: The principal aim of this study was to evaluate the wear resistance and surface hardness of dental nanocomposites. Three difference sizes (5 nm, 21 nm and 80 nm) of nanoTiO2 particles were treated with the 3-methacryloyloxy-propyl-trimethoxysilane (MPTMS). The nano-TiO2 was then place in urethane dimethacrylate (UDMA) matrix. Methods: Nano-TiO2 was sonically dispersed in an ethanol solution containing MPTMS. The treated particles were washed in pure ethanol and then dried. Wear resistance and surface hardness of eighteen groups of experimental dental nanocomposites were evaluated. Each group had a particle size category and was treated with three different concentrations of the silane, (MPTMS), which are 2.5, 10 and 30 wt %. For comparison, a commercially available dental resin, SR Adoro® (Ivoclar Vivadent, Cape Town, South Africa), used as the control, was reinforced with untreated and treated nano-TiO2. Results: Statistical analysis showed that the effect of the concentrations of MPTMS on wear resistance and surface hardness of specimens was significant (p<0.001), which is less than 0.05. The improvement of adding treated 80 nm TiO2 was better than that of adding treated 5 nm or 21 nm TiO2. Conclusions: It is concluded that the most available commercial product for dental restorations could be improved by the addition of nano-TiO2 with relatively large particles size

Facile fabrication of multifunctional transparent fire-retardant coatings with excellent fire resistance, antibacterial and anti-aging properties

A series of organophosphate-grafted nano-TiO2 was synthesized and then applied in amino resin to obtain multifunctional transparent fire-retardant coatings with superior fire resistance, antibacterial and anti-aging properties. Transparency analysis reveals that the addition of nano-TiO2 slightly decreases the light transmittance of the resulting MTiPPBs coatings, which is still remained a high level of transparency. The results of fire tests show that the presence of nano-TiO2 exhibits well synergistic effect on strengthening the smoke suppression property and fire resistance of the MTiPPBs coatings, which is ascribed to the formation of more P-containing cross-linked and aromatic structures in the condensed phase that improve the barrier effect of intumescent char against fire, as supported by scanning electron microscope (SEM) and energy dispersion spectrum (EDS) analyses. When the weight ratio of PPB and nano-TiO2 is 99.7:0.3, the obtained MTiPPB3 coating shows a 69.5% decrement in smoke density rating and an 83.3% decrement in flame spread rating in comparison to MTiPPB0 coating without nano-TiO2. The accelerated aging test reveals that the presence of nano-TiO2 can minimize the blistering, powdering, and cracking phenomena of the multifunctional coatings, thus displaying durable fire-resistant and smoke suppression effects. Meanwhile, the addition of nano-TiO2 greatly enhances the antibacterial activity of the multifunctional coatings, and MTiPPB3 coating obtains a 45.6% improvement in antibacterial activity index against Escherichia coli compared to MTiPPB0 coating without nano-TiO2.

Evaluation of Rheological and Anti-Aging Properties of TPU/Nano-TiO2 Composite-Modified Asphalt Binder.

Research on polyurethane-modified asphalt has become very popular. To this end, researchers have explored different ways, such as the use of polyurethane, to improve the road performance of asphalt. However, according to existing experimental research findings, it seems that the use of polyurethane alone cannot completely improve the road performance of asphalt. Therefore, the influence of nano-titanium dioxide and polyurethane on the rheological behavior and anti-ultraviolet aging properties of asphalt was studied. In this research, the rheological and microscopic tests of asphalt were conducted using Dynamic Shear Rheometer, Curved Beam Rheometer, and Fourier Infrared Spectrometer. The results show that the addition of TPU and nano-TiO2 to the asphalt not only improves the high- and low-temperature rheological behavior of the asphalt, but also improves the thermal oxygen resistance and UV aging resistance of the asphalt, and prolongs the use performance. Considering economic factors and environmental influences, among all the selected dosages, 4% TPU and 1% nano-TiO2 had the best performance.