The 10 most-cited articles in Advanced materials research, 2024

Metal oxide nanoparticles are widely used in various fields, including catalysis, sensing, energy storage, and more. Manganese dioxide (MnO 2 ) is a promising material for gas sensors due to its sensitivity to various gases, including oxidizing and reducing gases. The calcination temperature affects their size, crystallinity, surface area, and other properties. In the present research work, the influence of calcination temperature on the structural, electrical and gas sensing properties of MnO 2 nanoparticles or nanopowders was investigated. The MnO 2 nanopowder was calcinated at 200, 400, 600, and 800 °C in a muffle furnace for 4 hours. After that, using the calcinated powder of MnO 2 , the thick films were prepared using the standard screen printing technique. The structural characterizations were investigated using SEM, EDS, and XRD. It has been found that as the calcination temperature is increased, the electrical, structural, and gas-sensing properties of MnO 2 change. The prepared thick films calcinated at 200, 400, 600, and 800 °C are labeled as samples 1, 2, 3, and 4,…

Solid-state diffusion bonding effectively joins dissimilar materials, even with varying metallurgical properties and melting points. In this study, a Cu/Ni joint was produced at a bonding temperature of 950°C for 60 minutes under a vacuum. The microstructural and mechanical properties of the bonding interface were evaluated using scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS), microhardness tests, and X-ray diffraction (XRD). It was found that the EDS point scan analysis revealed the formation of a solid solution of Cu-Ni at the bonding interface. Since Cu-Ni exhibit complete solubility with each other, no intermetallic compounds (IMCs) were formed. The microhardness indicated that the bonding interface had a microhardness of 20% and 54% higher than the base metals (BM) of Ni and Cu, respectively.

Waste from plastic materials is outstripped due to the growth of industrialization and urbanization. Plastic materials are non-biodegradable; decomposition is not possible all the time. The recycling of plastic materials by using them in concrete will be a great deal for plastic management. This research investigation aims to measure the optimum percentage of plastic in concrete without a reduction in concrete strength and shear behavior of reinforced concrete. Using the provision of Mix Design ACI 211.1-91, the M28 concrete grade was created. Plastic materials have been collected and passed through a No-4 sieve (4.76mm). The combination of fine aggregates and ground plastic materials (RPET, PP) in the weight fraction of fine aggregate mix (0%, 2%, 4%, 6%, 8%, 10%) was used in the concrete. Concrete beams (750´150´150 mm) are reinforced with two 12 mm longitudinal steel bars in the tension zone, with proper clear cover for testing the shear capacity. In order to conduct the compressive and tensile splitting test, concrete specimens with a diameter of 100 mm and a height of 200 mm…

Microwave heating was used with a gas foaming method for fabricating limestone carbonated hydroxyapatite scaffold (SCHA). Carbonated hydroxyapatite (CHA) was produced from limestone as a calcium source using the co-precipitation method. For further treatment, 0.6 gr CHA powder was mixed in 1 ml H2O2 solution as a blowing agent. The slurry-foam-like CHA was heated in a microwave with different levels of heating power from 180 W to 720 W. The SCHA samples were characterized using X-ray diffraction (XRD), Fourier-transform infrared (FTIR), and Scanning electron microscope (SEM). The crystallinity and crystallite size were affected due to different rates of heating power in the microwave-assisted method. The increasing temperature decreased the crystallite size from 37.49 to 33.97(nm). However, other crystallinity trends were observed at 180 W because the lower power heating needed a longer time to be formed SCHA. The different power rates have an insignificant contribution to the morphology of the scaffolds.

In the field of fuel cell technology, the development of cost-effective catalysts is crucial for the commercialization of Alkaline Membrane Fuel Cells (AMFCs). Platinum (Pt) has traditionally been employed as the catalyst in AMFCs, but its high cost poses a major barrier to widespread adoption. In this study, a new catalyst material was developed by incorporating Manganese Dioxide (α-MnO2) into Carbon Nanotubes (CNTs) using hydrothermal synthesis techniques. The synthesized catalyst was characterized using Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD), and its electrocatalytic activity was evaluated through Linear Sweep Voltammetry (LSV) and CV through Rotating Disc Electrode (RDE) experiments. The results showed that the α-MnO2-CNT composite displayed strong durability in the alkaline environment and high electrocatalytic activity for oxygen reduction reaction (ORR). The LSV measurements revealed a current density of -4.1 mA/cm2 and an overpotential of -0.3V relative to Standard Calomel Electrode (SCE) in a 0.1M KOH electrolyte. Additionally, the α-MnO2-CNT…

Most of the bottles manufactured with PET polymer (polyethylene terephthalate) are used in beverage packaging and, after use, are turned into garbage, causing environmental problems. The concept of recycling and reuse of these materials for use in civil construction can become an interesting solution for the reduction of urban solid waste that would be destined to the formation of large volumes in sanitary landfills. Seeking to minimize this problem, this work used discarded PET bottles, ground into fibers, to prepare a concrete-based composite. The behavior of concrete composites with the addition of PET fibers in different compositions 7.5 kg/m³, 10 kg/m³ and 12.5 kg/m³ was evaluated. The choice of these concentrations aimed to study the addition of a reasonable amount of PET, characterizing greater reuse of a recycled material, seeking to provide a reinforcement effect in the cementitious matrix. The samples were subjected to mechanical tests of axial compression and diametral compression in a duly calibrated hydraulic press. For the axial compression test, the composite with 10…

The magnetic properties of magnetite nanoparticles (Fe 3 O 4 NPs) are being investigated. Fe 3 O 4 NPs were prepared using the co-precipitation method and oven dried. The magnetic properties are influenced by the electron environments of the Fe 3+ ions within the iron oxide structure. XPS spectra of Fe 3+ (2p 3/2 ) and (2p 1/2 ) show peaks around 706.45 eV and 720.76 eV, respectively. Furthermore, magnetite NPs dried at 60 °C exhibited the largest hysteresis loop at 50K and less at 300K. In addition, the values of Ms and Mr indicate ferromagnetic behavior in Fe 3 O 4 NPs. The result of this material shows high Ms (~38.638 emu/g) at 50K with Hc of 3.094K (near ferromagnetism) and ~33.843 emu/g at 300K with Hc of 0.000K (superparamagnetic). However, these magnetic properties are utilized for biomaterial applications such as separating biomolecules or coating core shells for nanoparticles, which presents an option for future biomedical technology.

3D-printing technology is being used as a regular approach in prototyping and the production of machine components. However, despite their metallic counterparts, there are many issues including infill pattern, density, and stress concentration coefficient in 3D printing that are not well-defined. The infill density plays a significant role in the printing time and mechanical properties of the printed objects. On the other hand, like metallic materials, changing geometry, such as fillet radius and hole alters the strength of the printed elements. In this work, experimental works have been conducted to determine the effect of infill density on the tensile strength of 3D printed elements. Furthermore, various standard specimens for tensile testing have been prepared to investigate the effects of fillet radius and in-plane hole diameters on the tensile strength of PLA 3D-printed elements with different infill density. Using the experimental results, the tensile stress concentration coefficients as a function of fillet radius, hole diameters, and infill density have been determined. The…

Green light-emitting YPO4:Tb3+ and YPO4:Tb3+: Ce3+ nanoparticles were synthesised at low temperatures using the polyol method. The phase purity, micromorphology and luminescence characteristics were studied using Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier Transfer Infrared absorption spectroscopy (FT-IR) and Photoluminescence spectroscopy (PL). Combined XRD and TEM analysis showed that the YPO4 nanoparticles crystallised into a single phase of tetragonal (I41/amd) structure. For all samples, the emission intensity at λem=543 nm assigned to 5D4→7F5 is more prominent than 5D4→7F6 with a maximum at λem=488 nm, and the asymmetric ratio was calculated and analysed. The asymmetric ratio is strongly correlated with the symmetry around the local environment of Tb3+ ions. A significant increase in the asymmetric ratio is observed with an increase in annealing temperature. The energy transfer from Ce3+ ions to Tb3+ ions was tested by studying the photoluminescence properties of YPO4:Tb3+ and YPO4:Tb3+: Ce3+ nanoparticles and how it results in the improvement of…

Nanoencapsulation technology has been used in food and pharmaceutical applications to increase bioactive chemical functioning and stability against external influences. To develop a cost-effective encapsulating procedure, additional optimization is required. This study employed response surface methodology (RSM) to optimize the encapsulation of anthocyanin-rich extract from black rice bran. The extract was encapsulated through pre-gelation and polyelectrolyte complex formation processes. Box-Behnken design was employed to determine the optimum conditions for the encapsulation process with the following process variables: chitosan concentration, pH, and CaCl2 concentration. Chemical characteristics, surface morphology, and particle size were used to describe the resultant capsules, which were then subjected to phytochemical analysis. The optimal encapsulation conditions for anthocyanin were 6.30 mg/mL chitosan, pH 5.5, and 36 mM CaCl2, with a 51.20 % encapsulation efficiency. The developed anthocyanin-loaded nanocapsule has a high TPC (3.87 mg GAE/g) and potent antioxidant activity…