Addition Of TiO2 Nanoparticles Research Articles

Enhanced polyacrylamide polymer hydrogels using nanomaterials for water shutoff: Morphology, thermal and rheological investigations at high temperatures and salinity

This study focuses on the synthesis, characterization, and performance evaluation of polyacrylamide (PAM)/polyethyleneimine (PEI) hydrogels enhanced with nanomaterials for potential application in conformance control in oil wells. The materials used include PAM with a molar mass of 25,000 Kg mol−1, PEI with an average weight molar mass of 25 Kg mol−1, and synthetic brine (ionic strength 0.6). Nanomaterials such as titanium dioxide (TiO2) nanoparticles, oxidized carbon nanotubes (CNT-ox), and graphene oxide (GO) were incorporated into the hydrogel matrix. A simple method was used for the incorporation of nanomaterials into the polymeric matrix, ensuring their good dispersion in the hydrogels formed. Characterization techniques including thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were employed to analyze the structure, morphology, and thermal stability of the hydrogels. Rheological measurements and gel strength evaluations were conducted to assess the performance of the hydrogels. Results indicate that the incorporation of nanomaterials enhanced the thermal stability, gel strength (Sydansk code), and resistance to syneresis of the hydrogels. Specifically, the addition of TiO2 nanoparticles exhibited the highest improvement in viscosity and thermal stability, attributed to strong interactions between TiO2 and PAM molecules. A notable decrease in syneresis percentages was observed with the inclusion of nanomaterials compared to the PAM reference sample, reaching 70.1 % for the hydrogel modified with GO. These findings suggest that nanomaterial-enhanced hydrogels hold promise for applications in conformance control in oil wells, offering improved stability and performance over extended periods of use.

Influence of TiO2 Nanoparticles on the Physical, Mechanical, and Structural Characteristics of Cementitious Composites with Recycled Aggregates.

The aim of this study is to analyze the effect of the addition of TiO2 nanoparticles (NTs) on the physical and mechanical properties, as well as the microstructural changes, of cementitious composites containing partially substituted natural aggregates (NAs) with aggregates derived from the following four recycled materials: glass (RGA), brick (RGB), blast-furnace slag (GBA), and recycled textolite waste with WEEE (waste from electrical and electronic equipment) as the primary source (RTA), in line with sustainable construction practices. The research methodology included the following phases: selection and characterization of raw materials, formulation design, experimental preparation and testing of specimens using standardized methods specific to cementitious composite mortars (including determination of apparent density in the hardened state, mechanical strength in compression, flexure, and abrasion, and water absorption by capillarity), and structural analysis using specialized techniques (scanning electron microscopy (SEM) images and energy dispersive X-ray spectroscopy (EDS)). The analysis and interpretation of the results focused primarily on identifying the effects of NT addition on the composites. Results show a decrease in density resulting from replacing NAs with recycled aggregates, particularly in the case of RGB and RTA. Conversely, the introduction of TiO2 nanoparticles resulted in a slight increase in density, ranging from 0.2% for RTA to 7.4% for samples containing NAs. Additionally, the introduction of TiO2 contributes to improved compressive strength, especially in samples containing RTA, while flexural strength benefits from a 3-4% TiO2 addition in all composites. The compressive strength ranged from 35.19 to 70.13 N/mm2, while the flexural strength ranged from 8.4 to 10.47 N/mm2. The abrasion loss varied between 2.4% and 5.71%, and the water absorption coefficient varied between 0.03 and 0.37 kg/m2m0.5, the variations being influenced by both the nature of the aggregates and the amount of NTs added. Scanning electron microscopy (SEM) images and energy dispersive X-ray spectroscopy (EDS) analysis showed that TiO2 nanoparticles are uniformly distributed in the cementitious composites, mainly forming CSH gel. TiO2 nanoparticles act as nucleating agents during early hydration, as confirmed by EDS spectra after curing.

Electrospun synthesis of polyaniline and titanium dioxide nanofibers as potential electrode materials in electrochemical hydrogen storage

To meet the imperative of advancing sustainable energy, prioritizing storage systems for clean energy, such as hydrogen, is crucial. However, challenges exist in hydrogen storage, and focusing on nanofibers that incorporate appropriate nanoparticles emerges as a promising approach to enhance storage capacity. In this study, polyaniline/polyvinyl alcohol (PANI/PVA) nanofibers and polyaniline/polyvinyl alcohol/titanium dioxide (PANI/PVA/TiO2) nanofibers were synthesized using the electrospinning method under constant conditions. After characterization of the nanofibers by various techniques, the nanocomposites were used as novel electrode materials for a first time for electrochemical hydrogen energy. Electrochemical tests were conducted on the synthesized nanofibers, and an optimal current of 1.5 mA was determined. The electrochemical analyses obtained revealed a significant improvement in the maximum hydrogen storage capacity with the presence of TiO2 nanoparticles. It increased from 654.8 mAh/g for PANI/PVA nanofibers to 1250 mAh/g for PANI/PVA/TiO2 nanofibers. The difference in storage capacity is attributed to the addition of TiO2 nanoparticles.

Electrospun 3D Curly Electret Nanofiber Air Filters for Particulate Pollutants

Amidst rapid industrialization and urbanization, air pollution has emerged as a global environmental challenge. Traditional air filtration materials face challenges in effectively filtering PM0.3 and often result in discomfort due to high air resistance when used for personal protection, as well as excessive energy consumption in industrial air purification applications. This study initially utilized extremely high environmental humidity to induce fiber formation, resulting in the preparation of a fluffy fiber membrane with a three-dimensional curly morphology, which increased the porosity to 96.93%, significantly reducing air resistance during filtration. Subsequently, rutile TiO2 with a high dielectric constant was introduced, exploiting the low pressure drop characteristic of the fluffy 3D curly fiber membrane combined with the electret effect of TiO2 nanoparticles to notably improve the issue of excessive pressure drops while maintaining filtration efficiency. The microstructure, morphology, and element distribution of the fibers were analyzed using FESEM and EDS. FTIR and XRD were employed to examine the functional groups and crystal structure within the fibers. The electret effect and filtration performance of the fiber membrane were investigated using an electrostatic tester and a particulate filtration efficiency tester. The results demonstrated that inducing fiber formation under high-humidity conditions could produce fibers with a 3D curly structure. The fiber membrane was highly fluffy, significantly reducing the pressure drop. Introducing an appropriate amount of titanium dioxide markedly improved the electrostatic effect of the fiber membrane, enhancing the filtration performance of the 3D curly PVDF/TiO2 composite fiber membrane. With a 0.5% addition of TiO2 nanoparticles, the filtration efficiency of the fiber membrane reached approximately 99.197%, with a pressure drop of about 49.83 Pa. This study offers a new approach to developing efficient, low-resistance air filtration materials, showcasing the potential of material innovation in addressing air quality challenges within the sustainable development framework.

Sweet cherry tree (Prunus avium) exudate gum-based film modification in a photoreactor: Effects of hydrogen peroxide oxidation, UV irradiation, and TiO2 nanoparticles

The fabrication possibility of nanocomposite film from sweet cherry tree exudate gum (SCG) was studied. To improve SCG film properties, oxidation with hydrogen peroxide, ultraviolet irradiation (UV-A and UV-C), and TiO2 nanoparticles (T-NPs) were used. Hydrogen peroxide oxidation at higher amounts decreased the water vapor permeability (WVP) and thickness and increased the mechanical properties and transparency. In comparison with the UV-A, UV irradiation of the C-type increased permeability, and elongation at break (EAB) and thickness, but reduced the tensile strength (TS), solubility, and transparency. The permeability and tensile strength were increased and elongation at break was decreased at a longer time of irradiation. The transparency values of fabricated films ranged from 65.3 to 79.5 % and WVP were in the range of 2.32–4.72 (×10−10 g/m.s.Pa). The measured TS of the SCG films were between 2.2 and 5 MPa and the EAB of the SCG films was between 35 and 68.7 %. The FTIR spectrum and SEM images revealed that the treatments could affect the bonds and the smoothness of the film surface, respectively. Images provided by AFM showed that the roughness of the films was increased by the addition of T-NPs. The incorporation of T-NPs increased the TS and decreased EAB and WVP. These results indicated that oxidation, UV irradiation and nanomaterials incorporation could be used to improve SCG film properties that are related to food packaging material.

Numerical Simulation and Sensitivity Analysis Using RSM on Natural Convective Heat Exchanger Containing Hybrid Nanofluids

This work presents a numerical analysis for exploring heat transfer phenomena in an enclosed cavity using magnetohydrodynamics natural convection. Because of the numerous real-world applications of nanofluids and hybrid nanofluids in industrial and thermal engineering developments, hybrid nanofluids are used as fluid mediums in the fluid field. A hexagonal-shaped heat exchanger is taken with two circular surfaces along the middle part. The upright circular surface acts as a homogeneous heat source, while the lower circular surface functions as a heat sink. The remaining portions of the adjacent walls are thermally insulated. The copper (Cu) and titanium dioxide (TiO2) nanoparticles are suspended into water to make a hybrid nanofluid. For solving the corresponding governing equations, the weighted-residual finite element method is applied. To explain the major outcomes, isotherms, streamlines, and many others 2D and 3D contour plots are involved graphically with a physical explanation for different magnitudes of significant parameters: Rayleigh number 103≤Ra≤106, Hartmann number 0≤Ha≤100, and nanoparticle volume fraction 0≤ϕ≤0.06. The novelty of this work is to apply response surface methodology on the natural convective hybrid nanofluid model, to visualize 2D and 3D effects, and to study the sensitivity of independent parameters on response function. Due to the outstanding thermal properties of the hybrid nanofluid, the addition of Cu and TiO2 nanoparticles into H2O develops the heat transfer rate to 35.85% rather than base fluid. Moreover, a larger magnitude of Ra and the accumulation of mixture nanoparticles result in the thermal actuation of a hybrid nanofluid. With greater magnetic impact, an opposite response is exhibited.

Microscopic investigation of the optical and morphological properties of iPP/TiO2 nanocomposite fibres using computed tomography technique.

In this article, the optical and structural properties of iPP/TiO2 nanocomposite fibres, considering three distinct extrusion speeds (25, 50 and 78 m/min) in addition to blank isotactic polypropylene samples were determined. Employing computed tomographic scans, localised optical defects in the nanocomposite fibres are unveiled, while refractive indices are examined by analysing transmitted intensity with incident light vibrating parallel and perpendicular to the fibre axis. The internal structure is further characterised through birefringence and density calculations. Mechanical properties, specifically stiffness, are probed by measuring elastic modulus values along the fibre. The investigation extends to the presence of TiO2 nanoparticles in the isotactic polypropylene matrix, inspecting their influence on the uniform morphology along and across the fibre. While the addition of TiO2 nanoparticles has many advantages, including enhanced properties, the study shows adverse effects on the morphological integrity of the fibres, particularly at higher extrusion rates. Micrographs are included to visually illustrate these findings, providing a comprehensive understanding of the complex interaction between extrusion rates, TiO2 nanoparticle incorporation, and the resulting optical and structural properties in iPP fibres.

In situ preparation of SnO2/Pd@TiO2 bilayer sensor for highly sensitive and fast detection of H2S based on electrohydrodynamic jet printing

A micron-scale bilayer H2S sensor fabricated by electrohydrodynamic (EHD) jet printing in situ was evaluated. The prepared sensor consisted of a Pd@TiO2 cover layer (porous catalytic sensing layer), a SnO2 bottom layer (electron transport layer) and a Sn-Ti transition layer between them. The addition of TiO2 nanoparticles to the cover layer led to a porous structure after one-step sintering. The increase in specific surface area and the formation of heterojunction effectively improved the sensor sensitivity. The PdO nanoparticles loaded on the surface of TiO2 nanoparticles further improved the performance due to its catalysis. Since the kinetic energy of droplets of the same size generated by EHD inkjet printing is about 48 times that of inkjet printing, the film density is much higher than that of inkjet printing. The relatively dense bottom layer, and the thick and stable transition layer improved the long-term stability of the sensor. The detection limit of the sensor is 6 ppb, with linear range of 0.02–10 ppm H2S. The response and recovery times are 7 s and 45 s (2 ppm H2S), respectively. After 9 months of intermittent measurement, the response of the sensor to 2 ppm H2S decreased by only 10.6%.

Investigation into improved characteristics of nanocomposites of kenaf and basalt fibers strengthened with titanium oxide nanoparticles

This study explores the thermal and mechanical properties of a composite material formed by blending kenaf and basalt fibers with titanium oxide nanoparticles. To assess its performance under various conditions, we conducted thermogravimetric analysis (TGA) and hardness, sorptivity, and water absorption tests. During experimentation, composite samples were created using kenaf and basalt fibers as the reinforcing matrix and TiO2 nanoparticles as the modifier. Initial findings suggest that the addition of TiO2 nanoparticles enhances the mechanical properties and water resistance of the kenaf and basalt fiber composite. Samples reinforced with TiO2 demonstrated superior hardness and lower water absorption, i.e., KBT2 exhibited a hardness of 92 Hv and a water absorption rate of 6.4%. The value of 0.1% for KBT2 from the sorptivity investigation was promising, indicating its potential applicability in moisture-sensitive environments. In addition, TGA results show that KBT2 exhibited 0%, 2.1%, 4.7%, and 8.3% weight loss, showing improved thermal stability and high resilience to higher temperatures. In conclusion, the development of a novel material combining kenaf and basalt fibers reinforced with TiO2 nanoparticles presents a promising eco-friendly, durable, and lightweight option for engineering applications. Realizing the full potential of this composite material necessitates further characterization and optimization research.

Improved shear property of Sn-3.0Ag-0.5Cu/Ni micro solder joints under thermal shock between 77 K and 423 K by adding TiO2 nanoparticles

The rapid development of space exploration technology was intensifying the desire for lead-free solders with high performance and reliability under extreme temperature environments. In this study, the influence of TiO2 nanoparticle addition on the microstructure, growth behavior of interfacial intermetallic compounds (IMCs) and shear property of Sn-3.0Ag-0.5Cu (SAC305)/Ni micro solder joints under thermal shock from 77 K to 423 K was systematically investigated. The results indicated that the grain size of β-Sn, IMC (Ag3Sn and (Cu,Ni)6Sn5) particles inside the solder was refined by adding 0.05 and 0.1 wt% TiO2 nanoparticles. Due to the spalling of interfacial IMCs into the solder occurring in all micro joints during thermal shock, the thickness of interfacial IMCs did not show a monotony increasing trend with increasing thermal cycles. However, the micro composite solder joint added with 0.05 and 0.1 wt% TiO2 nanoparticles always exhibited thinner interfacial IMC thickness and higher shear force compared with the plain micro joints during thermal shock. The inhibiting effect of TiO2 nanoparticles on the interfacial IMC growth could be explained by the adsorption theory and grain boundary pinning theory. The improvement in shear property of micro composite solder joints was primarily induced by the refinement of IMC particles in the solder and the reduced growth rate of interfacial IMCs by adding TiO2 nanoparticles.

Mechanical Performance and Corrosion Behaviour of Aluminum7075 Reinforced by Nano-Titanium dioxide

In this study, the stir casting technique (SCT) was applied to form aluminium (Al) nanocomposites with various weight percentages of nanotitanium dioxide powder (TiO2). The structural, mechanical, and corrosion properties of nanocomposites were investigated. The microstructure was taken by scanning electron microscopy (SEM), while the crystal structure of the specimens was obtained using X-ray diffraction (XRD). In addition, nanocomposites were immersed in 0.5 M HCl solution for potentiodynamic and corrosion rate measurements. The results showed that the best specimen is 0.03%, as it increased by 23% for hardness, but the tensile strength increased to 52%. Whereas, SEM images of the specimens reinforced with nanoparticles showed a clear homogeneity and diffusion of nanoparticles in the matrix. So, the addition of TiO2 nanoparticles to aluminium metal improved the hardness and tensile strength of the nanocomposites appreciably. The corrosion results showed that nanocomposite materials have higher corrosion resistance than Al7075-based composite materials.

The Influence of TiO2 Nanoparticles on the Physico–Mechanical and Structural Characteristics of Cementitious Materials

The urgent need for sustainable construction that corresponds to the three pillars of sustainable development is obvious and continuously requires innovative solutions. Cementitious composites with TiO2 nanoparticles (NT) addition show potential due to their improved durability, physico–mechanical characteristics, and self-cleaning capacity. This study aimed to evaluate the influence of NT on cementitious composites by comparing those with 2%–5% nanoparticles with a similar control sample without nanoparticles, as well as an analysis of cost growth. The experimental results showed an increase in bulk density of the material (4.7%–7.4%), reduction in large pore sizes by min. 12.5%, together with an increase in cumulative volume and cumulative specific surface area of small pore sizes, indicating densification of the material, also supported by SEM, EDS, and XRD analyses indicating acceleration of cement hydration processes with formation of specific products. The changes at microstructural level support the experimental results obtained at macrostructural level, i.e., modest but existent increases in flexural strength (0.6%–7.9%) and compressive strength (0.2%–2.6%) or more significant improvements in abrasion resistance (8.2%–58%) and reduction in water absorption coefficient (37.5%–81.3%). Following the cost–benefit analysis, it was concluded that, for the example case considered of a pedestrian pavement with a surface area of 100 m2, using 100 mm thick slabs, if these slabs were to be made with two layers, the lower layer made of cementitious composite as a reference and the upper layer with a thickness of 10 mm made of cementitious composite with 3% NT or 4% NT, the increase in cost would be acceptable, representing less than 15% compared to the cost for the exclusive use of cementitious composite without NT.

TiO2 nanoparticle embedded PEEKWC/PEI cross-linked ultrafiltration membrane: Improvement in flux and anti-fouling properties

Based on the previous study, the properties, separation efficiencies, and anti-fouling performances of TiO2 nanoparticle embedded PEEKWC/PEI cross-linked ultrafiltration membrane made via non-solvent-induced phase separation were investigated. SEM, contact angle measurement, ATR-FTIR, and other methods were used to characterize the membranes, and then the pure water flux (PWF) and dye rejection were measured. The TiO2 nanoparticle embedded PEEKWC/PEI cross-linked ultrafiltration membranes were prepared by stepwise solution blending method. Compared to the pristine PEEKWC/PEI cross-linked ultrafiltration membrane, the anti-fouling and pure water flux performances were enhanced as the addition of TiO2 nanoparticles. The pure water flux of TiO2 nanoparticle embedded membranes was significantly increased and could even reach 3368.2 LMH at 5 bar much greater than that of the pristine PEEKWC/PEI ultrafiltration membrane (1423.8 LMH), remaining a retention rate for BBR higher than 98.5%. And the TiO2 nanoparticle embedded PEEKWC/PEI cross-linked ultrafiltration membranes exhibited a certain degree of increase of FRR (higher than 80%) after UV illumination. After a series of characterisation, the dye wastewater treatment property of membranes was assessed through filtration of Coomassie brilliant blue and Congo red solutions and researches were conducted on the anti-fouling capabilities of membranes. The TiO2 nanoparticle embedded PEEKWC/PEI cross-linked ultrafiltration membranes exhibited self-cleaning efficiency with lower irreversible fouling ratio. The pure water flux recovery ratio following dye fouling was higher after being exposed to UV irradiation, which could be attributed to the TiO2 nanoparticles' photocatalytic destruction of organic pollutants.

In vitro degradation and dry sliding wear characteristics of AZ31/TiO2 nanocomposites for biomedical application

This study concentrated on the degradation and wear characteristics of nanocomposites reinforced with (0, 0.5, 1.5 and 2.5 wt%) titanium dioxide (TiO2) nanoparticles on the AZ31 Mg alloy fabricated by the stir casting method. Optical microscopy and FESEM images showed that the TiO2 nanoparticles were distributed uniformly and the intermetallic phase Mg17Al12 observed along the grain boundaries. The surfaces of the nanocomposite samples was gradually covered with a magnesium hydroxide (Mg(OH)2) protective layer after 48 h of immersion in simulated body fluid (SBF). The immersed composite samples contained several white hydroxyapatite and magnesium phosphate particles. The addition of up to 1.5 wt% TiO2 nanoparticles reduced the degradation rate of the nanocomposites in SBF, while further addition increased it. FESEM images of the immersed samples revealed the presence of corrosion pits and cracks on the AZ31 alloy and its nanocomposites. Under dry conditions with varying loads, the wear characteristics of fabricated nanocomposites were studied using computerised pin-on-disc equipment. The addition of TiO2 nanoparticles up to 1.5 wt% improved the wear resistance of the nanocomposites. However, the further addition increased the coefficient of friction (COF) and wear loss due to agglomeration and porosity in the nanocomposites. The FESEM morphology of the worn surface and wear debris revealed that abrasion was the primary wear mechanism at low loads, and abrasion with severe plastic deformation and delamination were dominant at higher loads.

Evaluating the energy consumption, structural, and corrosion resistance properties of photocatalytic TiO2-based PEO coatings on pre-anodized AA2024-Al

In this work, a thorough investigation is carried out to develop plasma electrolytic oxidation (PEO) coatings on pre-anodized AA2024-Al at various concentrations of TiO2 dispersed in a water base electrolyte of sodium silicate, sodium phosphate dodecahydrate, and potassium hydroxide in order to determine the effect of TiO2 incorporation on energy consumption, coating growth, surface morphology, photocatalytic behavior, and associated long-term corrosion resistance properties. The pre-anodization time is controlled to develop a 20.0 ± 1.6 µm thick anodic film, where a reduction of ∼66 % in the energy consumption (kW h m2 µm−1) is observed compared to the PEO developed without pre-anodic precursors, while the addition of TiO2 nanoparticles (Degusa-P25) into the base electrolyte results in reductions of ∼68 %, 64 %, and 51 % for the PEO coatings developed at 2, 5 and 10 g/L TiO2-based electrolyte, respectively. TiO2-based PEO process is found to improve growth rate, coating microstructure with lower porosity and defects, and reduce energy consumption (for a coating of a given thickness). The photocatalytic activity of TiO2 was investigated by photodegrading phenol under simulated sunlight conditions, where the higher concentration of TiO2 nanoparticles affected the phenol photodegradation efficiency, whereas the effectiveness of TiO2 concentration on the corrosion resistance properties of PEO coatings was observed with nearly one-order higher impedance magnitude (after 336 h) than the PEO layer without TiO2.

Comparative Evaluation of TiO2 Nanoparticle Addition and Postcuring Time on the Flexural Properties and Hardness of Additively Fabricated Denture Base Resins

Three-dimensionally (3D)-printed fabricated denture bases have shown inferior strength to conventional and subtractively fabricated ones. Several factors could significantly improve the strength of 3D-printed denture base resin, including the addition of nanoparticles and post-curing factors. This study evaluated the effect of TiO2 nanoparticle (TNP) addition and the post-curing time (PCT) on the flexural properties and hardness of three-dimensionally (3D)-printed denture base resins. A total of 360 specimens were fabricated, with 180 specimens from each type of resin. For evaluating the flexural properties, bar-shaped specimens measuring 64 × 10 × 3.3 mm were used, while, for the hardness testing, disc-shaped specimens measuring 15 × 2 mm were employed. The two 3D-printed resins utilized in this study were Asiga (DentaBASE) and NextDent (Vertex Dental B.V). Each resin was modified by adding TNPs at 1% and 2% concentrations, forming two groups and an additional unmodified group. Each group was divided into three subgroups according to the PCT (15, 60, and 90 min). All the specimens were subjected to artificial aging (5000 cycles), followed by testing of the flexural strength and elastic modulus using a universal testing machine, and the hardness using the Vickers hardness test. A three-way ANOVA was used for the data analysis, and a post hoc Tukey’s test was used for the pairwise comparisons (α = 0.05). Scanning electron microscopy (SEM) was used for the fracture surface analysis. The addition of the TNPs increased the flexural strength in comparison to the unmodified groups (p < 0.001), while there was no significant difference in the elastic modulus and hardness with the 1% TNP concentration. Among the TNP groups, the 2% TNP concentration significantly decreased the elastic modulus and hardness (p < 0.001). The SEM showed a homogenous distribution of the TNPs, and the more irregular fracture surface displayed ductile fractures. The PCT significantly increased the flexural strength, elastic modulus, and hardness (p < 0.001), and this increase was time-dependent. The three-way ANOVA results revealed a significant difference between the material types, TNP concentrations, and PCT interactions (p < 0.001). Both concentrations of the TNPs increased the flexural strength, while the 2% TNP concentration decreased the elastic modulus and hardness of the 3D-printed nanocomposites. The flexural strength and hardness increased as the PCT increased. The material type, TNP concentration, and PCT are important factors that affect the strength of 3D-printed nanocomposites and could improve their mechanical performance.

Surface Modification of Fast-Growing Wood with a Titanium-Dioxide-Based Nanocoating to Improve Weathering Resistance

Acacia mangium requires the addition of a finishing material to increase its resistance to weathering. Herein, the effectiveness of a nanocoating containing titanium dioxide nanoparticles (TiO2-NPs) as a finishing material for mangium wood was investigated. The coating material formulations used were oil-based (V1) and water-based (V2) varnishes with TiO2-NP concentrations of 1% (CT1), 5% (CT5), and 10% (CT10) (w/v). The uncoated and coated samples were subjected to weathering periods of 0, 2, and 4 months. The results showed that the addition of TiO2 nanoparticles to the V1 and V2 varnishes resulted in more gradual colour changes after the weathering period. The surface of the mangium wood also became smoother after being coated. However, the surface roughness increased with the duration of the weathering period. The wettability (K-value) of the sample decreased after coating, indicating that the coated sample was more hydrophobic than the uncoated sample. The results of a photocatalyst test, which analysed the effectiveness of the coatings, showed that the best coating material formulas were V1-CT10 and V2-CT10, as they degraded 75.21% and 71.03% of methylene blue content, respectively. Fourier transform infrared analysis showed that mangium wood did not undergo rapid weathering after the nanocoating treatment, as indicated by an insignificant decrease in the peak absorption intensity of the main structural functional groups of wood.

3D-Printed nanocomposite denture base resin: The effect of incorporating TiO2 nanoparticles on the growth of candida albicans.

To develop a biocompatible denture base resin/ TiO2 nanocomposite material with antifungal characteristics that is suitable for 3D-printing denture bases. TiO2 nanoparticles (NPs) with a 0.10, 0.25, 0.50, and 0.75 weight percent (wt.%) were incorporated into a commercially available 3D-printed resin material. The resulting nanocomposite material was analyzed using Lactate dehydrogenase (LDH) and AlamarBlue (AB) assays for biocompatibility testing with human gingival fibroblasts (HGF). The composite material was also tested for its antifungal efficacy against Candida albicans. Fourier transform infrared (FTIR) and Energy Dispersive X-ray Spectroscopy (EDX) mapping were conducted to assess the surface coating and the dispersion of the NPs. LDH and AB assays confirmed the biocompatibility of the material showing cell proliferation at a rate of nearly 100% at day 10, with a cytotoxicity of less than 13% of the cells at day 10. The concentrations of 0.10, 0.25, and 0.50 wt.% caused a significant reduction (p<0.05) in the number of candida cells attached to the surface of the specimens (p<0.05), while 0.75 wt.% did not show any significant difference compared to the control (no TiO2 NPs) (p>0.05). FTIR and EDX analysis confirmed the presence of TiO2 NPs within the nanocomposite material with a homogenous dispersion for 0.10 and 0.25 wt.% groups and an aggregation of the NPs within the material at higher concentrations. The addition of TiO2 NPs into 3D-printed denture base resin proved to have an antifungal effect against Candida albicans. The resultant nanocomposite material was a biocompatible material with HGFs and was successfully used for 3D printing. This article is protected by copyright. All rights reserved.

Smart Indicator Film Based on Sodium Alginate/Polyvinyl Alcohol/TiO2 Containing Purple Garlic Peel Extract for Visual Monitoring of Beef Freshness.

The aim of this study was to prepare a novel pH-sensitive smart film based on the addition of purple garlic peel extract (PGE) and TiO2 nanoparticles in a sodium alginate (SA)/polyvinyl alcohol (PVA) matrix to monitor the freshness of beef. FT-IR spectroscopy revealed the formation of stronger interaction forces between PVA/SA, PGE, and TiO2 nanoparticles, which showed good compatibility. In addition, the addition of PGE improved the tensile strength and elongation at break of the composite film, especially in different pH environments, and the color response was obvious. The addition of 1% TiO2 nanoparticles significantly improved the mechanical properties of the film, as well as the light barrier properties of the film. PGE could effectively be uniformly dispersed into the composite film, but it also had a certain slow-release effect on the release of PGE. PGE had high sensitivity under different pH conditions with rich color changes, and the color showed a clear color change from red to yellow-green when the pH increased from 1 to 14. The same change was observed when it was added to the film. In particular, by applying this film to the process of beef preservation, we judged the freshness of beef by monitoring the changes in the TVB-N value and pH value during the storage process of beef and found that the film showed obvious color changes during the storage process of beef, from blue (indicating freshness) to red (indicating non-freshness), and finally to yellow-green (indicating deterioration), which indicated that the color change of the film and the freshness of the beef maintained a highly consistent.

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.