Zirconia Nanoparticles Research Articles

A Comprehensive Investigation of Nanocomposite Polymer Flooding at Reservoir Conditions: New Insights into Enhanced Oil Recovery

Recently, the polymer-nanoparticle combination has garnered significant interest in enhanced oil recovery (EOR) due to its promising experimental results. However, the previous research was mostly directed at silica, while alumina and zirconia nanoparticles have gotten the least consideration. Unlike previous works, this study aims to investigate the influence of three NPs: Silica (SiO2), Alumina (Al2O3), and Zirconia (ZrO2) on hydrolyzed polyacrylamide (HPAM). To this end, three nanocomposites were formulated: HPAM-SiO2, HPAM-Al2O3, and HPAM-ZrO2. Rheological evaluations were performed to examine the viscosity degradation of the three nanocomposites and HPAM under reservoir conditions. Furthermore, interfacial tension (IFT) at the oil–water interface and wettability studies were investigated. Moreover, sand-pack flooding was performed to examine the incremental oil recovery. The results revealed that the polymer viscosity was boosted by 110%, 45%, and 12% for HPAM-SiO2, HPAM-Al2O3, and HPAM-ZrO2 respectively under the investigation range of temperature. Moreover, the polymer viscosity was improved by 73%, 48%, and 12% for HPAM-SiO2, HPAM-Al2O3, and HPAM-ZrO2 respectively under the investigation range of salinity. Nanocomposites are also found to be a remarkable agent for reducing interfacial tension and changing the contact angle. The flooding experiments confirmed that the EOR by HPAM, HPAM-SiO2, HPAM-Al2O3, and HPAM-ZrO2, was 8.6%, 17.4%, 15.3%, and 13.6% of OOIP respectively. Moreover, the results of flooding experiments were well validated and matched by numerical simulation. Such findings of this work afford new insights into EOR and reinforce the promising outlook of such technique at the field scale.

Characterization and anticancer evaluation of zirconia nanoparticles synthesized via green route using sophora flavescens roots extract

The emergence of drug resistance in cancer cells has impeded recent progress in cancer therapy, leading to the investigation of novel anticancer drugs. The fabrication of metal and ZrO2 nanoparticles is a promising path with prospective applications across diverse technological domains. The present study investigates the potential anticancer effects of ZrO2 NPs obtained from the root extract of Sophora flavescens on MCF-7 breast cancer cells. The structural and chemical features of these nanoparticles are analyzed using several techniques such as flow cytometry, SEM, TEM, FTIR, and UV–vis spectroscopy. The examination of XRD and TEM images demonstrates the significant contribution of plant root extract in enhancing the efficiency of nanoparticles, leading to the formation of nearly tetragonal crystal structures with an average size of 8 nm. The MTT experiment verifies the nanoparticles' anticancer activity, which depends on the dosage. The IC50 value of 253 μg/mL indicates the half-maximal inhibitory concentration. The optical microscope reveals an unusual sight: MCF-7 cells appear more spherical and less dense at higher concentrations. This research also investigates the antibacterial properties of ZrO2 nanoparticles against harmful bacteria, particularly those resistant to multiple drugs. The diffusion disk assay indicates that the nanoparticles are active against drug-resistant isolates, with zones of inhibition ranging from 31 to 55 millimeters. Additionally, the researchers noted a positive correlation between nanoparticle concentration and the size of the inhibition zone. Overall, the data indicates the potential of ZrO2 NPs to aid in cancer therapy as well as in combating infections.

Effect of titanium dioxide and zirconium dioxide nanoparticle incorporation on the thermal conductivity of heat-activated polymethylmethacrylate denture base resins: An in vitro experimental study.

The aim is to determine thermal conduction by heat-activated polymethylmethacrylate (PMMA) infiltrated with 1 weight% Titanium Dioxide (TiO2) and 1 weight% Zirconium Dioxide (ZrO2) nanoparticles and to compare with that of conventional PMMA. In vitro experimental study. Eighteen disc shaped specimens with a thickness of 5 mm and diameter of 50 mm, were fabricated and grouped according to the material used: Group B1 (resin infiltrated with 1 weight% TiO2), Group B2 (resin infiltrated with 1 weight% ZrO2), and Control Group B3 (heat-activated conventional PMMA resin). Disc-shaped specimens were analyzed for thermal conductivity using "modified guarded hot plate apparatus" in the thermal lab of the Indian Space Research Organisation. One-way ANOVA followed by Tukey's post hoc test was used to compare the arithmetic means of all three groups. A statistically significant difference was noted among all three groups. Group B2 had the maximum thermal conductivity, followed by Group B1. Thermal conductivity was the least for Group B3. A post hoc comparison revealed that the difference was significant between Group B2 and Group B3. Nano ZrO2 addition in PMMA increased its thermal conductivity. There is evidence that it improves its mechanical properties as well. Hence, Nano ZrO2 addition in PMMA is highly recommended. Nano TiO2 addition in PMMA did not provide any significant advantage in terms of thermal conductivity, but its addition in PMMA is justified because of its mechanical and antimicrobial properties.

Facile Synthesis and Characterization of Zirconia Nanoparticles in Dental Applications

Scientists and dentists use tiny particles called ZrO2/Nps (Zirconia Nanoparticles) in medicine. In addition, zirconia particles are commonly used in the realm of medicine and dentistry. They are ideal for tooth structure because of their beneficial properties. The objective of this research is to prepare zirconium oxide nanoparticles in a simple and easy way. Nano-zirconium oxide is prepared using the co-precipitation method. The produced powder was diagnosed using tools like X-ray diffraction, microscopy, and spectroscopy, which also analyzed its properties such as X-ray spectroscopy and density measurement. The XRD results confirmed that the powder product has high purity. The crystal size range is 27.97nm. The results match the (JCPDS (ZrO2) sheet No.79-1769). The EDX test revealed the presence of the following elements (Zr–O). The test of SEM (Scanning Electron Microscope) show that the particles nearly spherical and the size was 74.03nm. The Zr–O stretching modes and the Zr–O2–Zr bending modes were confirmed by the FTIR (Fourier transform infrared). The density of ZrO2/Np was measured several times and determined it to be (5.07±0.12 g/cm3).

Adaptive mechanisms of dental pulp stem cells (DPSCs) in response to oral disease: Evaluating chitosan-calcium zirconium nanoparticle biomaterials for tissue engineering

This study aims to investigate the adaptive strategies employed by dental pulp stem cells (DPSCs) in response to oral disease conditions, focusing on their survival and proliferation. DPSCs possess regenerative potential and play a crucial role in the repair and regeneration of dental tissues. The study explores the coping mechanisms of DPSCs under oral disease conditions using a chitosan-based biomaterial reinforced with calcium zirconium nanoparticles (CZNP). The investigation assesses the viability and proliferation of DPSCs in the presence of oral disease conditions and evaluates the performance of the chitosan-CZNP biomaterial. The study presents the characterization and performance evaluation of drug-loaded biomaterials with varying weight percentages of CZNP. Parameters such as porosity, drug release, fracture toughness, tensile strength, degradation rate, and apatite formation are examined. The results demonstrate that increasing the weight percentage of CZNP leads to higher porosity and drug release while maintaining or enhancing fracture toughness, tensile strength, and apatite formation. Notably, the biomaterial containing 7.5 wt% CZNP exhibits the highest drug release, fracture toughness, and apatite formation. These findings suggest that the chitosan-CZNP biomaterial effectively supports the survival and proliferation of DPSCs under oral disease conditions. An artificial neural network (ANN) is employed to predict the properties of samples with different weight percentages and apatite formation. The ANN successfully estimates the degradation rate, tensile strength, fracture toughness, drug release, and porosity of the samples. This research enhances our understanding of the coping mechanisms of DPSCs and highlights the potential of chitosan-CZNP biomaterials in oral tissue engineering and regenerative medicine. Further investigations are warranted to explore the long-term effects and clinical applications of these biomaterials in the treatment of oral diseases.

Bioorganic macromolecules crowned zirconia nanoparticles: protein-rich fish mucus inspired synthesis and their antibacterial efficacy assessment

Abstract The bioinorganic material, such as fish mucus macromolecules crowned zirconia nanoparticles (ZrO2 NPs) was synthesized via green methodology and has been investigated their efficacy on Gram-positive and Gram-negative bacterial strains that inhabit the oral cavity, gastrointestinal tracts, and colon. The environmentally benign synthesis methodology was used for fabricating biofunctionalized ZrO2 NPs with three different concentrations of C. striatus epidermal mucus. Spherical morphology with a size ranging from 7 to 25 nm of synthesized granular was identified by FESEM analysis. The powder XRD diffractions of synthesized ZrO2 NPs were confirmed with the previously reported standard literature. Upon being subjected to a primary microbial study, the synthesized ZrO2 NPs were shown to exhibit antibacterial activity against the tested bacterial pathogens. However, another Gram-negative bacterial stain, Proteus vulgaris shows almost similar efficiency to standard antibacterial drugs. Interestingly, all Gram-positive bacterial strains show a high zone of inhibition at higher concentrations of synthesized ZrO2 NPs. In general, the antibacterial activity study proved that the synthesized biofunctionalized ZrO2 NPs may be applied as an efficient health care beneficial material.

Synthesize uniform ZrO2 NPs by non-coordination solvents and modification for high refractive film

Zirconia nanoparticles (ZrO2 NPs) are considered promising functional materials due to their high refractive index, thermal stability, and relatively wide bandgap. They can be particularly valuable when blended with monomer resins to create transparent composite materials with tunable refractive indices. However, the challenge of synthesizing uniformly sized and transparently dispersible ZrO2 NPs in organic resin monomers has been an ongoing research problem. In this study, we proposed an improved method based on an existing synthesis route for the production of ZrO2 NPs. We employed a sol-gel approach and introduced a simple yet effective strategy to synthesize ZrO2 NPs. Using high-boiling non-coordinating solvent squalane to adjust the concentration of oil amine ligands in the solution, helped to balance the nucleation and growth of ZrO2, thereby improving the size uniformity of ZrO2 NPs. In addition, the addition of sodium hydroxide (NaOH) to the reaction system effectively promoted the crystal growth of ZrO2 without affecting its crystal structure and crystallinity. Simultaneously, this addition significantly reduced the content of surface oleylamine (OAm) ligands. Finally, ZrO2 was modified using 2-Ethylhexanoic acid (EHA) and 3-methacryloxypropyltrimethoxysilane (KH-570), achieving successful transparent dispersion within the high refractive index acrylic monomer, benzyl acrylate (BZA). In-situ polymerization was used with a UV initiator to produce a refractive index continuously tunable BZA/ZrO2 composite film.

Resistive switching properties of a nanostructured layer of mixed ZrO2 phases obtained in low-pressure arc discharge plasma

The controlled vacuum-arc synthesis of zirconium dioxide (ZrO2) nanoparticles is considered, which makes it possible to regulate the percentage ratio of the monoclinic and tetragonal phases. The samples were characterized using XRD analysis, SEM, HRTEM analysis, FT-IR analysis, TG/DTA analysis and EPR spectroscopy. It has been established that the formation of the tetragonal phase is associated with the formation of a large number of oxygen vacancies formed due to high-speed quenching of nanoparticles. Reducing the operating gas pressure in a vacuum chamber from 180 Pa to 30 Pa makes it possible to obtain nanoparticles up to 2 nm in size. The synthesized ZrO2 nanoparticles do not contain foreign impurities and when heated, the weight loss is up to 7 %. The process of local resistive switching in the contact of an atomic force microscope (AFM) probe to a nanostructured ZrO(2-x) layer on a conducting substrate has been studied. Cyclic current-voltage characteristics demonstrate the existence of stable states of high and low resistance, switched by changing the polarity of the applied voltage. The coexistence of the m- and t-ZrO2 phases (and the resulting oxygen nonstoichiometry in the interboundary regions) provides conditions for the formation/destruction of a filament from oxygen vacancies, which determine the conductivity of the dielectric in the LRS state.

Two‐step simulation combining large eddy simulation and population balance Monte Carlo for nanoparticle synthesis in flame spray pyrolysis

AbstractA two‐step simulation approach combining large eddy simulation (LES) for turbulent flame and multidimensional/multivariate population balance Monte Carlo (PBMC) for nanoparticle dynamics is proposed to explore the detailed flame fields and particle dynamics of zirconia nanoparticles in a flame spray pyrolysis (FSP) reactor. The turbulent combustion of gas and spray are simulated by the nonlinear LES‐partially stirred reactor model. Thereafter, the differentially weighted PBMC is applied for the first time to describe the spatially resolved formation and growth of nanoparticles using the flame fields derived from LES as an input. An efficient submodel for particle spatial transport in multidimensional grids is adopted and tested to account for the effect of thermophoresis, convective and diffusion of the nanoparticles. This methodology is successfully applied to an FSP case, demonstrating a reliable level of fidelity when compared to experiments and other model. Simulation results are discussed, in particular the flame fields and the size, morphology, as well as polydisperse primary particle and aggregates size distribution.

The Role of Oxygen Vacancies in Phase Transition and the Optical Absorption Properties within Nanocrystalline ZrO2.

Zirconia (ZrO2) nanoparticles were synthesized using a solvothermal method under varying synthesis conditions, namely acidic, neutral, and alkaline. X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were leveraged to investigate the phase evolution and topographical features in detail. The resulting crystal phase structures and grain sizes exhibited substantial variation based on these conditions. Notably, the acidic condition fostered a monoclinic phase in ZrO2, while the alkaline condition yielded a combination of tetragonal and monoclinic phases. In contrast, ZrO2 obtained under neutral conditions demonstrated a refinement in grain sizes, constrained within a 1 nm scale upon an 800 °C thermal treatment. This was accompanied by an important transformation from a monoclinic phase to tetragonal phase in the ZrO2. Furthermore, a rigorous examination of XPS data and a UV-visible spectrometer (UV-vis) analysis revealed the significant role of oxygen vacancies in phase stabilization. The notable emergence of new energy bands in ZrO2, in stark contrast to the intrinsic bands observed in a pure monoclinic sample, are attributed to these oxygen vacancies. This research offers valuable insights into the novel energy bands, phase stability, and optical absorption properties influenced by oxygen vacancies in ZrO2. Moreover, it proposes an innovative energy level model for zirconia, underpinning its applicability in diverse technological areas.

Green Synthesis and Investigation of Antimicrobial Activity and Compressive Resilience of Glass Ionomer Cement Modified With Zirconia Nanoparticles: An In Vitro Study.

Background Glass ionomer cement (GIC) serves as a crucial biomaterial in dental restoration, offering applications in filling, lining, and adhesive procedures. Nevertheless, its mechanical properties often fall short, particularly in regions subjected to considerable stress. To address this issue, zirconia nanoparticles are incorporated at specific levels. Aim To assess the antimicrobial efficacy and compressive resilience of GIC modified with zirconia nanoparticles synthesized through green synthesis methods. Material and methods Zirconia nanoparticles were synthesized via a green method utilizing aloe vera extract in solvent form. These nanoparticles were then mixed into GIC at different concentration levels. Group I incorporated zirconia nanoparticles at a concentration of 3%, Group II at 5%, and Group III at 10%, while Group IV was the control, consisting of traditional GIC. Following that, samples were prepared and underwent characterization through various analytical techniques. The ability to inhibit microbial growth and the compressive resilience of the groups were examined. Microbial inhibition against the bacterial strains was assessed through minimum inhibitory concentration (MIC), and the ability to withstand compression was gauged by measuring the maximum force the specimen could endure before fracturing. Data underwent analysis with Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 24.0, Armonk, NY). Repeated measures of analysis of variance (ANOVA) were utilized to gauge average MIC values and compressive strength. Following this, Tukey's post hoc test was employed for pairwise comparisons. Results The findingsindicated, incorporating zirconia nanoparticles into GIC led to an improvement in its antimicrobial effectiveness, with a noticeable enhancement observed as the weight percent (% wt) of the additive increased. This improvement was notably noticeable in its effectiveness against Streptococcus mutans and Lactobacillus, exceeding that of the control with a noteworthy distinction. Furthermore, there were significant enhancements in compressive strength, in Group I (180.48 ± 1.02), Group II (191.25 ± 0.52), and Group III (197.52 ± 0.75), compared to Group IV (167.22 ± 1.235), with significant disparities (p < 0.05). Conclusion The research illustrates that introducing green-synthesized zirconia nanoparticles into GIC leads to heightened bactericidal potency and compressive resilience when contrasted with the control group (Group IV). Notably, the highest concentration of 10% demonstrated the most favourable antimicrobial attributes alongside enhanced strength. Consequently, integrating green-synthesized zirconia nanoparticles into GIC holds potential as a proficientmaterial. In future studies, there should be an exploration of molecular chemistry and bonding mechanisms to enhance our comprehension of its capabilities.

One-Pot Synthesis of Silver/Zirconium Nanoparticles Using Sargassum tenerrimum for the Evaluation of Their Antibacterial and Antioxidant Activities.

The global health threat posed by worldwide antimicrobial resistance necessitated immediate multisectoral action by the scientific community to achieve sustainable development goals. Silver and zirconium nanoparticles (Ag/ZrO-NPs), known for their antimicrobial properties, have the potential to combat pathogens effectively, making them versatile for various applications across different fields. This study aims to synthesize and characterize Sargassum tenerimum-mediated Ag/ZrO-NPs and evaluate their antioxidant and antibacterial efficacy against multidrug resistant (MDR) pathogens. The synthesis of Ag/ZrO-NPs using the one-pot green synthesis method was conducted and followed by using characterization techniques, namely, UV-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction analysis (XRD), and energy-dispersive X-ray analysis (EDX). The antibacterial activity was assessed using the agar well diffusion method, and antioxidant activity was determined using the DPPH(2,2-diphenyl-1-picrylhydrazyl) method. Statistical analysis was analyzed using the IBM SPSS Statistics for Windows, version 21.0 (released 2012, IBM Corp., Armonk, NY). The green-synthesized Ag/ZrO-NPs exhibited acolor change from dark brown to creamy white, indicating the successful reduction of the nanoparticles. UV-analysis peaks were observed at 310-330 nm, while the FT-IRanalysis showed the peaks at various wavelengths, such as 648.9 cm-1 (alkyne C-H bond), 1041.14 cm-1 (aliphatic fluoro compounds, C-F stretch), 1382.54 cm-1 (dimethyl -CH3), 1589.6 cm-1 (primary amine, N-H bond), and 3353.8 cm-1 (aliphatic secondary amine, N-H stretch). The crystallinity of the nanoparticles was determined to be 59.5%, while the remaining 40.5% exhibited an amorphous structure.The SEM image revealed the spherically agglomeratedstructure of the nano-ranged size Ag/ZrO-NPs. The EDX analysis indicated the presence of elemental compositions Zr (16.2%), Ag (18.8%), and C (28.7%)in the green-synthesized Ag/ZrO-NPs. These nanoparticles demonstrated significant antibacterial activity against Pseudomonas aeruginosa, Enterococcus faecalis, and Methicillin-resistant Staphylococcus aureus (MRSA). The moderate antibacterial activity against E. coli showed thesignificant antioxidant activity in a dose-dependent manner. The green-synthesized Ag/ZrO-NPs showed notable antibacterial and antioxidant activity. In future aspects, it may be used as a potential drug after completion of in-vivo and in-vitro studies.

Plant-Based Extracts as Reducing, Capping, and Stabilizing Agents for the Green Synthesis of Inorganic Nanoparticles

The synthesis of inorganic nanoparticles for diverse applications is an active research area that involves physical and chemical methods, which typically are expensive, involve hazardous chemical reagents, use complex equipment and synthesis conditions, and consume large amounts of time and energy. Thus, green synthesis methods have emerged as eco-friendly and easy alternatives for inorganic nanoparticle synthesis, particularly the use of plant-based extracts from fruit juice, leaves, seeds, peel, stem, barks, and roots, which act as reducing, capping, and stabilizing agents, contributing to the Sustainable Development Goals and circular economy principles. Therefore, diverse inorganic nanoparticles have been synthesized using plant-based extracts, including gold, silver, titanium dioxide, zinc, copper, platinum, zirconium, iron, selenium, magnesium, nickel, sulfur, cobalt, palladium, and indium nanoparticles, which exhibit different biological activities such as antioxidant, antimicrobial, dye degradation, cytotoxic, analgesic, sedative, wound-healing, skin protection, sensor development, and plant-growth-promoting effects. Therefore, this review summarizes the advantages and limitations of plant-based extracts as reducing, capping, and stabilizing agents for inorganic nanoparticle green synthesis.

CMAS corrosion resistance of scandia, ceria, yttria‐stabilized zirconia ceramic

AbstractSc2O3–CeO2–Y2O3– stabilized zirconia (ScCeYSZ) nanoparticles with different percentages of stabilizer agents [sample1: 1.8 wt.% (Sc2O3) 8.3 wt.% (CeO2) 1.9 wt.% (Y2O3), sample 2: 1.1 wt.% (Sc2O3) 9.0 wt.% (CeO2) 1.9 wt.% (Y2O3), sample 3: .5 wt.% (Sc2O3) 9.6 wt.% (CeO2) 1.9 wt.% (Y2O3) stabilized zirconia] were synthesized with Pechini method and consolidated by spark plasma sintered method. The results showed that despite the [(sample)1: 1.8 wt.% (Sc2O3) 8.3 wt.% (CeO2) 1.9 wt.% (Y2O3)] had lower density and higher porosity percentage compared to other samples, it had better calcium–magnesium–alumina–silicate (CMAS) corrosion resistance compared to other samples and the yttria‐stabilized zirconia nanopowders (nano‐YSZ) sample. It was due to the higher acidic nature and tetragonality of the (sample)1 sintered body compared to other samples and YSZ ceramic in the CMAS corrosive medium. Moreover, the results of phase and microstructural analysis following CMAS corrosion revealed the formation of the monoclinic phase and rod‐shaped CaAl2Si2O8 particles on the surface of the sampled sintered sample. However, the nano‐YSZ sample corroded homogenously and delamination occurred after the CMAS corrosion test.

Nanoparticle-Modified 3D-Printed Denture Base Resins: Influence of Denture Cleansers on the Color Stability and Surface Roughness In Vitro.

This study aimed to evaluate the influence of denture cleansers on the color, stability, and surface roughness of three-dimensional (3D)-printed denture base resins modified with zirconium dioxide nanoparticles (nano-ZrO2). A total of 440 specimens were fabricated using one heat-polymerized resin, and two 3D-printed resins (NextDent and ASIGA). According to the nano-ZrO2 content, the specimens for each resin were divided into five groups (0%, 0.5%wt, 1%wt, 3%wt, and 5%wt). Each concentration was divided into four subgroups (n = 10) based on the immersion solution (distilled water, sodium hypochlorite, Corega, and Fittydent) and immersion duration (360 and 720 days). The color changes (∆E00) and surface roughness (Ra, µm) of each specimen were measured at different time intervals (base line, 360 days, 720 days) using a spectrophotometer and a non-contact profilometer, respectively. The results were statistically analyzed using ANOVA and a post hoc Tukey's test (α = 0.05). Sodium hypochlorite showed the highest significant color change of all the denture base resins (p < 0.001). The average value of ΔE00 for sodium hypochlorite was significantly higher than the values for the other solutions (Fittydent, Corega, and water) (p < 0.001). Color stability was significantly affected by immersion time for all types of solutions except Corega (p < 0.001). All of the tested immersion solutions (distilled water, sodium hypochlorite, Corega, and Fittydent) showed a significant increase in the surface roughness of all the denture base resins (p < 0.05). Surface roughness was substantially increased by immersion time for all types of solution except Fittydent (p < 0.001). Denture cleansers can result in substantial color change and affect the surface roughness of unmodified and nanoparticle-modified denture base resins. Therefore, the selection of denture cleanser and appropriate types of material is critical for denture longevity.

Biogenic synthesis of Azadirachta indica-mediated zirconium oxide nanoparticles: photocatalytic degradation of methylene blue and antimicrobial activity

Biogenic synthesis of Azadirachta indica-mediated zirconium oxide nanoparticles: photocatalytic degradation of methylene blue and antimicrobial activity

Development of resin‐based dental composites containing hydroxyapatite and zirconia nanoparticles

AbstractIn clinical applications, resin‐based dental composites primarily face challenges with fractures and secondary caries. To overcome these issues, the physical characteristics of dental composites, especially mechanical properties, need to be improved. Hydroxyapatite (HA), present in the structure of the teeth, is preferred due to its biological properties, and zirconia (ZrO2) nanoparticles are known to enhance the mechanical properties of this type of composites. The aim of this study is to develop resin‐based dental composites containing HA and ZrO2 nanoparticles. The study also aims to explore the synergistic effect of these two nanoparticles on the physical properties of the developed composites. Composites with nine different compositions were prepared by mixing the components with the help of a mortar mill. The flexural and compressive strength, polymerization shrinkage, depth of cure and water sorption, and solubility properties of the prepared composites have been investigated. All composites have been found to meet the requirements of ISO 4049 standard. Among them, composite containing 5 wt. % HA and 1 wt. % ZrO2 (H5Z1) has exhibited the highest flexural strength with an increase of 58% compared to the control sample, and composite containing 3 wt. % HA and 2 wt. % ZrO2 (H3Z2) has exhibited the highest compressive strength with an increase of 22% compared to the control sample. Other physical properties of the composites have been found to be in an acceptable level.Highlights Dental composites with HA and ZrO2 fillers were developed by a mortar mill. Synergistic effect of HA and ZrO2 nanoparticles was investigated. Mechanical properties of dental composites were significantly improved. Physical properties of dental composites were found to be at acceptable levels. Depth of cure decreases with increasing HA and ZrO2 loading.

Enhanced Mass Activity and Durability of Bimetallic Pt-Pd Nanoparticles on Sulfated-Zirconia-Doped Graphene Nanoplates for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cell Applications.

Developing highly active and durable Pt-based electrocatalysts is crucial for polymer electrolyte membrane fuel cells. This study focuses on the performance of oxygen reduction reaction (ORR) electrocatalysts composed of Pt-Pd alloy nanoparticles on graphene nanoplates (GNPs) anchored with sulfated zirconia nanoparticles. The results of field emission scanning electron microscopy and transmission electron microscopy showed that Pt-Pd and S-ZrO2 are well dispersed on the surface of the GNPs. X-ray diffraction revealed that the S-ZrO2 and Pt-Pd alloy coexist in the Pt-Pd/S-ZrO2-GNP nanocomposites without affecting the crystalline lattice of Pt and the graphitic structure of the GNPs. To evaluate the electrochemical activity and reaction kinetics for ORR, we performed cyclic voltammetry, rotating disc electrode, and EIS experiments in acidic solutions at room temperature. The findings showed that Pt-Pd/S-ZrO2-GNPs exhibited a better ORR performance than the Pt-Pd catalyst on the unsulfated ZrO2-GNP support and with Pt on S-ZrO2-GNPs and commercial Pt/C.

Tailoring high-refractive-index nanocomposites for manufacturing of ultraviolet metasurfaces

Nanoimprint lithography (NIL) has been utilized to address the manufacturing challenges of high cost and low throughput for optical metasurfaces. To overcome the limitations inherent in conventional imprint resins characterized by a low refractive index (n), high-n nanocomposites have been introduced to directly serve as meta-atoms. However, comprehensive research on these nanocomposites is notably lacking. In this study, we focus on the composition of high-n zirconium dioxide (ZrO2) nanoparticle (NP) concentration and solvents used to produce ultraviolet (UV) metaholograms and quantify the transfer fidelity by the measured conversion efficiency. The utilization of 80 wt% ZrO2 NPs in MIBK, MEK, and acetone results in conversion efficiencies of 62.3%, 51.4%, and 61.5%, respectively, at a wavelength of 325 nm. The analysis of the solvent composition and NP concentration can further enhance the manufacturing capabilities of high-n nanocomposites in NIL, enabling potential practical use of optical metasurfaces.

Improvement of mechanical performance on zirconium dioxide nanoparticle synthesized magnesium alloy nano composite

With excellent mechanical properties and distinct solidification, the AZ31B series magnesium alloy has great potential for targeting engineering applications and synthesized via die casting process found a drawback on oxidation results porosity and reduced mechanical properties. Here, the magnesium alloy AZ31B series nanocomposite was synthesized with varied weight percentages of zirconium dioxide nanoparticles through a liquid metallurgy route with an applied stir speed of 200 rpm under an argon nature. With the help of a scanning electron microscope, the distribution of particles in the composite surface was found to be homogenous and void-free surface, which output results in less percentage of porosity (<1 %), and the composite contained 6 wt% ZrO2 offers superior yield strength (212 ± 3 MPa), tensile strength (278 ± 2 MPa), and impact strength of 16.4 ± 0.4 J/mm2. In addition, 8 wt% ZrO2 blended composite showed the maximum microhardness value (78.3 ± 1 HV). The best-enhanced result of NC3 (AZ31B/6 wt% ZrO2) is suggested for lightweight to high-strength structural applications.