Nanocomposite Powders Research Articles

Engineering hard ferrite composites by combining nanostructuring and Al3+ Substitution: From nano to dense bulk magnets

We have investigated the bottom-up sol-gel synthesis of nanocomposite powders comprising two magnetic phases (hexagonal Sr ferrite and spinel Co ferrite) in order to outline a strategy to obtain permanent magnets with large coercivities via low-cost and scalable syntheses. The correlation between morphological, structural and macroscopic magnetic properties of Al-substituted SrFe12O19 and SrFe12O19/CoFe2O4 nanocomposites was analyzed in detail. The hysteretic behavior can be tuned by cation substitution and/or modulation of the super-exchange coupling at the interface of the constituting phases. The magnetic data, supported by Monte Carlo simulations, indicates enhanced magnetic coupling within the composite: this observation underscores the significance of soft crystallite size and epitaxial growth quality at the interface as key factors influencing super-exchange coupling strength, ranging from fully coupled to essentially decoupled composites. Bulk magnets with high density were manufactured by compacting these nanostructured phases using spark plasma sintering, without an applied magnetic field. Consolidation of powders significantly impacted magnetic properties, by increasing remanent magnetization and decreasing coercivity due to enhanced super-exchange coupling. The presence of two phases hindered reciprocal growth, influencing coercivity differently in various compositions. Overall, the compaction enhanced magnet performance through improved particle alignment and super-exchange coupling, offering the potential for optimized magnet design.

Synthesis of Mo-Cu nanocomposite powder by hydrogen reduction of copper nitrate coated MoO3 powder mixture

The fabrication of Mo-based nanocomposite powder with homogeneous dispersion of Cu was investigated. The fine MoO3 powders were prepared by high energy ball milling, and Cu particles on the ball-milled powder surfaces were formed by calcination of a precursor solution copper nitrate. In the powder mixture calcined at 300 °C, MoO3 and CuO appeared in the form of aggregates with fine particles. Microstructural analysis showed that the oxide powders were changed to Mo-Cu nanocomposite powders with an average particle size of about 150 nm and had microstructural homogeneity by hydrogen reduction at 800 °C for 1 h. These results are help to optimize the synthesis process of homogeneous Mo-Co nanocomposite powders.

Preparation and Characterization of TiB2/Al3Ti/Al2O3 Composite Nano-powder

Preparation and Characterization of TiB2/Al3Ti/Al2O3 Composite Nano-powder

Enhanced random vector functional link based on artificial protozoa optimizer to predict wear characteristics of Cu-ZrO2 nanocomposites

Owing to the absence of scientific methods for predicting nanocomposites' wear rates, a freshly updated machine learning method that uses an Artificial Protozoa Optimizer (APO) to forecast the tribological performance of Cu-ZrO2 nanocomposites was proposed. The updated model was used to predict the coefficients of friction and wear rates of Cu-ZrO2 nanocomposites produced in this work. Copper-zirconia nanocomposite powders were fabricated utilizing the ball milling process, varying in milling time and ZrO2 weight percentage. The effect of reinforcement percentage and milling time on the morphology and microstructure of the copper composite powders was characterized. The study concentrated on the effects of high-energy ball milling on the morphology, microstructure, and microhardness of the resulting composites. After cold compaction at 700 MPa of pressure, the resultant powders were sintered for 2 h at 950 °C in a hydrogen atmosphere. Based on the results, a 20-h milling time is the best option for creating a Cu-ZrO2 nanocomposite with evenly distributed reinforcement. The microhardness and wear rate of the Cu-15%ZrO2 nanocomposites are improved by 66.2 %, and 81.1 %, respectively, when compared to pure copper. The crystallite size decreases significantly with the addition of ZrO2, reaching 32.5 and 11.1 nm for samples containing 5 and 15 % weight percent ZrO2. That is why there is a rise in wear and mechanical properties. For Cu-ZrO2 nanocomposites with reinforcement content up to 15 %, the model constructed using the APO method demonstrated excellent forecasting of the wear rate and coefficient of friction.

Study on the engineering properties of abaca/hemp/kenaf natural fiber mats reinforced with Anogeissus latifolia, polyester resin, and fly ash nano powder nanocomposites

Study on the engineering properties of abaca/hemp/kenaf natural fiber mats reinforced with Anogeissus latifolia, polyester resin, and fly ash nano powder nanocomposites

Comparative study on structural, morphological, and optical properties of MS/Fe3O4 nanocomposites and M-doped Fe3O4 nanopowders (M = Mn, Zn)

In the present work, the un-doped, M-doped magnetite (Fe3O4); (M = Mn, Zn), and MS/Fe3O4 composite nanopowders with a cubic spinel-type structure and average crystallite size range from 8.30 to 12.33 nm were synthesized by co-precipitation method. The FESEM images revealed the shape of particles are spherical with a grain size in the range of 33.44–49.77 nm. Through the analysis of reflectance data using Tauc’s model, the direct band gap energies of 2.98 eV, 2.93 eV, 3.01 eV, 2.85 eV, and 2.95 eV were determined for Un-doped Fe3O4, Mn-doped Fe3O4, Zn-doped Fe3O4, MnS/Fe3O4 composite, and ZnS/Fe3O4 composite NPs respectively. The parameters such as extinction coefficient and refractive index of the nanoparticles were computed by the Kramers–Kronig (K–K) method. Non-linear optical (NLO) parameters were computed from DRS data using the Wemple–Di-Domenico (WDD) model. The calculated third-order NLO susceptibility χ(3)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\chi }^{(3)}$$\\end{document} and also electrical susceptibility χe\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\chi }_{\\left(e\\right)}$$\\end{document} represented the maximum value for MnS/Fe3O4 composite NPs compared to the other samples. Considering the advanced optical parameters of MS/Fe3O4 composite samples, these particles can be suitable candidates for non-linear optical applications.

Temperature annealing and aluminum atomic concentration effect on structural, morphological and optical properties of ZnO-Al2O3 nanocomposites powders and photocatalytic performances

Temperature annealing and aluminum atomic concentration effect on structural, morphological and optical properties of ZnO-Al2O3 nanocomposites powders and photocatalytic performances

Enhanced properties of hard metal WC-Ni processed from nanostructured powders

In this study, we investigated the effects of nanostructured composite powders (WC-Ni), nickel binder content, and sintering techniques on the morphology and mechanical properties of tungsten carbide. An alternative low-temperature gas-solid reaction route with a short reaction time was employed to produce nanostructured composite powders with 5 and 15 wt% Ni. The powders were consolidated using spark plasma sintering (SPS) and conventional vacuum furnace sintering at temperatures of 1350 °C and 1450 °C. The composite powders were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and particle size measurements. The expansion/contraction of the compacted nanocomposite powders was studied through dilatometric analysis. The composite powders exhibited a uniform distribution of Ni, in both compositions. For the WC-5 wt% Ni nanocomposite powders, the average crystallite sizes for WC and Ni were 41.6 nm and 46.2 nm, respectively. While, for the WC-15 wt% Ni nanocomposite, the crystallite sizes for WC and Ni were 45.6 and 38.4 nm. The sintered composites were evaluated through XRD, SEM, measurements of density and Vickers hardness. The enhanced sinterability of the nanostructured powders enabled their consolidation into (WC-Ni) hard metal with densities approaching the theoretical relative density of 96.07 %, even with low binder content (5 wt% Ni). This is attributed to the uniform distribution of Ni and an extensive Ni-WC interface present prior to sintering. The SPS process at 1350 °C produced sintered bodies (WC-5 wt% Ni and WC-15 wt% Ni) with higher Vickers hardness (2322 HV and 1512 HV, respectively) and superior microstructural quality compared to samples produced by conventional vacuum furnace techniques. These results demonstrated that the mechanical properties of the system WC-Ni processed by SPS are superior to those obtained by vacuum furnace. Therefore, WC-Ni hard metals processed by this approach is a promising alternative to conventional hard metals (WC-Co) for a wide range of applications.

Corrosion characteristics of PPY/GO/CuO nano-composite powder reinforced epoxy coatings on IF steel

The present study has been designed to test the corrosion performance of epoxy based nano-composite coatings on Interstitial Free (IF) steel. PPy and PPy nano-composite powders were formed by polymerization of pyrrole using ferric chloride oxidant. PPy nano-composite powders were synthesized including Graphene oxide (GO) and Copper oxide (CuO) nano-particles. Four combinations have been undertaken in this study viz. pure PPy, PPy-GO (PG), PPy-CuO (PC) and PPy-GO-CuO (PGC). SEM/EDS and XRD results validated the uniform embedding of nano-particles in the pyrrole matrix during polymerization. Moreover, TGA analysis has also confirmed the enhancement of thermal stability of PPy with the incorporation of nano-particles. Further, epoxy (EP) powder was loaded with different concentration of synthesized composite powders to optimize the weight percent (wt%) of PPy, GO and CuO for testing the corrosion characteristics. The different coating configurations were applied on IF steel samples and electrochemical & salt spray testing have been conducted. It has been concluded that coating configuration EP/P2G0.5C1.0 has shown maximum corrosion protection efficiency (ηPE) of approximately 99 %. Moreover, other three configurations EP/P2, EP/P2G0.5 and EP/P2C1.0 have also shown noteworthy results of ηPE of 85, 96 and 97 % respectively. SEM images for cross-sectional view of coatings have also confirmed the uniformity of coatings on to the IF steel. The suitability of these synthesized coatings has also been verified via adhesion test evidencing no significant change in adhesive strength.

CsPbBr3@PbSO4 nanocomposites with near-unity photoluminescence and ultrastability via in-water in situ embedding synthesis strategy

Perovskite quantum dots (PQDs) are emerging as promising nanomaterials for optoelectronic applications. However, developing a cost-effective green synthesis process that simultaneously possesses satisfactory photoluminescence quantum yield (PLQY) and stability remains a severe challenge. Here, CsPbBr3@PbSO4 nanocomposites with a near-unity PLQY of 99.8 % and robust ambient stability are synthesized in situ in water via 4-Bromobenzenesulfonic acid and ditetradecylamine ligands. Notably, these nanocomposites show no decline in PLQY even after being immersed in water for over 250 days, and also exhibit superior stability against heating, ultrasonication, UV irradiation, anion exchange, and erosion by polar solvents. First-principles calculations reveal that CsPbBr3@PbSO4 nanocomposites can form a natural quantum well structure, which effectively promotes the radiative recombination of carriers in CsPbBr3 QDs. Meanwhile, the remarkable stability is attributed to the ultrahigh decomposition enthalpy of PbSO4 that serves as a strong barrier preventing the invasion of anions and polar media into the embedded CsPbBr3 QDs. Finally, besides the convenient application of green fluorescent paper, a fingerprint recognition is demonstrated by fabricating a bright-green LED integrated with the CsPbBr3@PbSO4 nanocomposites powder and a commercial UV chip. This work provides a new strategy for green synthesis and practical application of high-efficient and ultrastable PQDs.

Synthesis of TaB2-TaC nanocomposite powders by a boro-carbothermal reduction route

This paper introduces the boron/carbon thermal reduction reaction, represented by the equation 2Ta2O5+ B4C + 11 C = 2TaB2 + 2TaC + 10CO (g), as a novel reaction pathway for synthesizing TaB2₋TaC composite powders. Subsequently, the SPS technique is employed for the fabrication of TaB2-TaC composite ceramics via sintering. The article begins by elucidating the fundamental process of this reaction and constructing a phase diagram through thermodynamic calculations. The experimental results demonstrate that adjusting the synthesis temperature and the proportion of the boron source in the raw materials enables effective control over the ratio of the two phases within the composite materials, allowing the TaB2 phase content to be tailored within the range of 38.1–60 %. Moreover, elevating the synthesis temperature and increasing the proportion of the boron source effectively mitigate the C,O impurity content in the composite powders and facilitate the TaB2 step-growth process. It is noteworthy that the hardness of TaB2-TaC composite ceramics sintered at 2000°C using the optimized complex-phase powder as the precursor reaches 21.7±0.5 GPa, and the fracture toughness attains 5.2±0.2 MPa⋅m1/2.

Mechanochemical dehydration and crystallization of supersaturated zirconia–alumina composite nano powders

Mechanochemical dehydration and crystallization of supersaturated zirconia–alumina composite nano powders

Micropatterning MXene/TiO2 Nanocomposite Ink for Gas Sensing

This work describes the preparation, characterization and micropatterning of MXene (Ti3C2/TiO2) nanocomposite inks. The MXene nanopowder was oxidized to Ti3C2/TiO2 nanocomposite powder by stirring in air for 3 hours using air aging method. The Ti3C2/TiO2 nanocomposite powder was then dispersed into Dimethyl Sulfoxide (DMSO) solvent, and the Ti3C2/TiO2 ink was prepared by using 1% mass fraction of Polyvinylpyrrolidone (PVP) solution as dispersant. The two-dimensional layered nanostructure of MXene and the characteristic peaks of TiO2 were observed by Raman and XRD results. SEM and TEM results show the layered structure of MXene nanoparticles as well as TiO2 nanoparticles with a diameter of about 2 nm on a single layer of MXene. FTIR results confirms that Ti-O bonds and Ti-C bonds indicating that part of Ti3C2 was oxidized to TiO2. The results of Brunauer Emmett Teller (BET) test on Ti3C2/TiO2 nanocomposite ink show that the specific surface area of the ink is 10.7194 m²/g and the maximum adsorption of N2 is 32.039cm3/g. Thermogravimetric analysis (TGA) indicate that Ti3C2/TiO2 exhibited excellent thermal stability, with a mass loss of only 15% at 800°C. In order to achieve the optimal printing effect, plasma surface treatment was carried out on the gold-plated silicon wafers, Polyethylene terephthalate (PET), and glass substrates, which decreases the contact angle of the ink on these substrates. The printing of Ti3C2/TiO2 nanocomposite ink on the substrate using the atomized printing technique with a mask plate enables printing of straight lines with a line width of 5µm. Film thickness can be controlled by adjusting the distance between the printhead and the substrate, as well as the pressure of the atomized printing jet.

Enhanced photocatalytic degradation of harmful pollutants by MoO3/SiO2/MXene nanocomposite powder catalyst

The search for materials to treat wastewater is especially crucial. Herein, we have prepared 1D molybdenum oxide (MoO3) nanobelts through a hydrothermal approach. The binary (MoO3/SiO2) and ternary composites of MoO3/SiO2/MXene were synthesized via ultrasonication route. The as-prepared MoO3, MoO3/SiO2, and MoO3/SiO2/MXene composites were employed to investigate the photocatalytic behavior of two organic dyes, methyl orange (MO) and crystal violet (CV). The % degradation of MO in the presence of MoO3 nanobelts and MoO3/SiO2 was calculated to be 48.9 % and 74.4 %, respectively. In the case of CV dye, the degradation (%) was observed at 53.7 % and 75.9 %. The MoO3/SiO2/MXene composite revealed the best photocatalytic behavior against both MO and CV dyes by removing 94.7 % and 97.7 % under visible light irradiation. The rate constant values of MoO3 nanobelts, MoO3/SiO2 and MoO3/SiO2/MXene composite for MO dye were calculated to be 0.00568 min−1, 0.01156 min−1, and 0.02399 min−1 and for CV dye 0.00679 min−1, 0.01208 min−1, and 0.02798 min−1 respectively. A scavenging test was carried out to monitor the main photo-active species that take part during the photocatalysis and hydroxyl radicals were found to be the highly active species during whole photodegradation progression. The SiO2 particles function as a good adsorbent medium and transfer the adsorbed organics toward more active sites to advance the reaction. 2D MXene nanosheets, as good conductors, reduce the recombination rate of charges, offer large surface area, and facilitate fast transfer of charges. The results suggest that MoO3/SiO2/MXene composite is a potential contender for wastewater remediation applications.

High–Strength Porous TiNbZrTaFe Alloys Fabricated by Sintering of Nanocomposite Powder Precursor with Space Holder Technique

High–Strength Porous TiNbZrTaFe Alloys Fabricated by Sintering of Nanocomposite Powder Precursor with Space Holder Technique

Fabrication and characterization of Ti-12Mo/xAl2O3 bio-inert composite for dental prosthetic applications.

Introduction: Titanium (Ti)-molybdenum(Mo) composites reinforced with ceramic nanoparticles have recently significant interest among researchers as a new type of bio-inert material used for dental prosthetic applications due to its biocompatibility, outstanding physical, mechanical and corrosion properties. The current work investigates the impact of alumina (Al2O3) nanoparticles on the properties of the Ti-12Mo composite, including microstructure, density, hardness, wear resistance, and electrochemical behavior. Methods: Ti-12Mo/xAl2O3 nanocomposites reinforced with different Al2O3 nanoparticles content were prepared. The composition of each sample was adjusted through the mechanical milling of the elemental constituents of the sample for 24h under an argon atmosphere. The produced nanocomposite powders were then cold-pressed at 600 MPa and sintered at different temperatures (1,350°C, 1,450°C, and 1,500°C) for 90min. Based on density measurements using the Archimedes method, the most suitable sintering temperature was found to be 1,450°C. The morphology and chemical composition of the milled and sintered composites were analyzed using back-scattering scanning electron microscopy (SEM) and X-ray diffraction (XRD). Results and Discussion: The results showed that the addition of Mo increased the Ti density from 99.11% to 99.46%, while the incorporation of 15wt% Al2O3 in the Ti-12Mo composite decreased the density to 97.28%. Furthermore, the Vickers hardness and wear behavior of the Ti-Mo composite were enhanced with the addition of up to 5 wt% Al2O3. The sample contains 5 wt% Al2O3 exhibited a Vickers hardness of 593.4HV, compared to 320HV for pure Ti, and demonstrated the lowest wear rate of 0.0367mg/min, compared to 0.307mg/min for pure Ti. Electrochemical investigations revealed that the sintered Ti-12Mo/xAl2O3 nanocomposites displayed higher corrosion resistance against a simulated artificial saliva (AS) solution than pure Ti. The concentrations of Ti, Mo, and Al ions released from the Ti-12Mo/xAl2O3 nanocomposites in the AS solution were within the safe levels. It was found from this study that; the sample of the composition Ti-12Mo/5wt%Al2O3 exhibited appropriate mechanical properties, biocompatibility, corrosion resistance against the AS solution with acceptable ion concentration released in the biological fluids. Therefore, it can be considered as a new bio-inert material for potential applications in dental prosthetics.

Energy Storage Application of CaO/Graphite Nanocomposite Powder Obtained from Waste Eggshells and Used Lithium-Ion Batteries as a Sustainable Development Approach.

The reuse of waste materials has recently become appealing due to pollution and cost reduction factors. Using waste materials can reduce environmental pollution and product costs, thus promoting sustainability. Approximately 95% of calcium carbonate-containing waste eggshells end up in landfills, unused. These eggshells, a form of bio-waste, can be repurposed as catalytic electrode material for various applications, including supercapacitors, after being converted into CaO. Similarly, used waste battery electrode materials pose environmental hazards if not properly recycled. Various types of batteries, particularly lithium-ion batteries, are extensively used worldwide. The recycling of used lithium-ion batteries has become less important considering its low economic benefits. This necessitates finding alternative methods to recover and reuse the graphite rods of spent batteries. Therefore, this study reports the conversion of waste eggshell into calcium oxide by high-temperature calcination and extraction of nanographite from spent batteries for application in energy storage fields. Both CaO and CaO/graphite were characterized for their structural, morphological, and chemical compositions using XRD, SEM, TEM, and XPS techniques. The prepared CaO/graphite nanocomposite material was evaluated for its efficiency in electrochemical supercapacitor applications. CaO and its composite with graphite powder obtained from used lithium-ion batteries demonstrated improved performance compared to CaO alone for energy storage applications. Using these waste materials for electrochemical energy storage and conversion devices results in cheaper, greener, and sustainable processes. This approach not only aids in energy storage but also promotes sustainability through waste management by reducing landfills.

Introducing a computer simulation to model flexural vibrations of sandwich structures reinforced by advanced nanocomposites surrounded by auxetic concrete foundation

This study introduces a computer simulation framework aimed at analyzing the flexural vibrations of sandwich structures comprising a polymer core sandwiched between two face sheets reinforced with graphene oxide powder (GOP) nanocomposites. The sandwich structures are situated on an auxetic concrete foundation, incorporating sophisticated theoretical formulations to approximate the three-dimensional displacement fields of GOP-reinforced rectangular plates under varying loading conditions. The research addresses the complex interplay of material properties and geometric configurations, crucial for optimizing the structural performance of advanced composite materials in practical applications. The computational model integrates analytical techniques to predict the dynamic behavior of the sandwich structure’s flexural vibrations. Key parameters such as the dispersion of GOP within the polymer matrix, and the auxetic properties of the concrete foundation are systematically varied and analyzed to understand their impact on the overall structural response. Results from the simulations provide insights into the natural frequencies of the GOP-reinforced sandwich structures, offering valuable data for design engineers and materials scientists. The study underscores the potential of graphene oxide powder nanocomposites in enhancing the mechanical performance of sandwich structures, particularly when supported by innovative foundation materials like auxetic concrete. Future research directions include validation and further refinement of the computational model to accommodate additional complexities and real-world conditions.

Spherical polystyrene/zinc oxide nanocomposite powder fabricated by continuous process chain of melt mixing and indirect heating

Polymer powders are limited by particle size, shape, and properties in various applications. Preserving the chemical properties of the material throughout the process is a critical part of developing consistently shaped nanocomposite powders across diverse polymer types. The goal of this study is to demonstrate continuous methods to produce spherical Polystyrene (PS) and zinc oxide (ZnO) nanocomposites. A single-screw extruder is used to melt mix PS pellets with ZnO nanoparticles, followed by pelletization, dry grinding, and spheroidization in a Downer Tower to form spherical polymers. To minimize agglomeration, the process incorporates an ethanol treatment and a final sieving step. The resulting nanocomposite powder exhibits exceptional flowability and well-defined spherical morphology. Additionally, incorporating ZnO nanoparticles enhanced the thermal stability and glass transition temperature of the nanocomposite while reducing particle size distribution. Thermogravimetric analysis and X-ray diffraction confirm the preservation of the chemical structure of the spherical nanocomposite specimens throughout processing.

Novel piezoelectric xNF–(1−x)PZT materials for catalytic/photocatalytic removal of pollutants

This study explores the potential of using nanocomposite powders consisting of NiFe2O4 and Pb(Zr0.47Ti0.53)O3 in varying concentrations (30 %, 40 %, 50 %, and 70 wt.%) to remove pollutants from water-based solutions. XRD, FTIR, and XPS analyses showed the successful synthesis of the pure ferrite phase directly on the ferroelectric templates. The presence of all elements specific to parents NF and PZT can be observed by XPS and EDS analyses. The AFM and PFM observations suggest that the addition of NF can locally enhance and possibly improve the piezoelectric properties. The degradation efficiency was tested under different conditions (mechanical stirring, ultrasonic vibration, and UV irradiation). The results showed that the nanocomposites exhibited high efficiency in the degradation of the reactive yellow 84 dye and Bisphenol A, with an optimum composition of x = 40 % NiFe2O4 addition, in line with PL tests. Also, no leached Pb ions could be detected in the solution. Furthermore, a simple rotational stirring method was found to be a fast and effective way to degrade the micropollutants.