Results in Materials最新文献

The production of nanoparticles using biogenic synthesis techniques is becoming more prominent due to its diverse applications. In this research, the extract from mango leaf was utilized to fabricate a green method for producing Ag-doped and undoped TiO₂ nanoparticles that is non-toxic, economical, and environmentally favorable. Titanium isopropoxide (TTIP) was used as a precursor for Ag-doped and undoped TiO₂ nanoparticle production, where the concentrations of the dopant material silver were 2.5 and 3%. Acquired undoped and Ag-doped TiO₂ nanoparticles were characterized using several analytical techniques. The morphological, structural, and photocatalytic activity were evaluated using XRD, SEM, EDX, and UV–Vis spectroscopy. In the XRD analysis, undoped and Ag-doped TiO₂ nanoparticles indicated the formation of an anatase phase, but there was no rutile phase. The photocatalytic activity and nanoparticles’ band gap were assessed using UV–Vis spectroscopy. The UV–Vis Spectroscopy also revealed a reduced band gap energy (E_g) of Ag-doped TiO₂ nanoparticles than the undoped TiO₂ Nanoparticles (NPs). The development of photocatalytic activity and features of the “Red-shift” characteristic was established by the progressive photo-degradation of Methylene Blue (MB). The SEM analysis revealed that Ag-doped TiO₂ nanoparticles showed more agglomeration than the undoped sample. The average particle size of undoped TiO₂ nanoparticles was 38.33 nm, and the size gradually increased for 2.5% and 3% Ag-doping. Utilizing EDX analysis, the doping of Ag+ in the TiO₂ lattice structure was confirmed. We can predict from the findings that utilizing biosynthesized TiO₂ nanoparticles can be an excellent option for water purification, dye-sensitized solar cells, photo-degradation process, etc., in the long run.

The electronic, mechanical, elastic, dynamical, and optical properties of the ZrCoAs half-Heusler compound have been systematically investigated using the plane wave self-consistent field approach with the Perdew-Burke-Erzerhof generalized gradient approximation (GGA-PBE) exchange-correlation functional. The study includes examinations with and without spin orbit coupling (SOC) effects. Results indicate a decrease in the Kohn-Sham band gap with the inclusion of SOC effects. Electronic bandgap formation was attributed to Co 3d, Zr 3d, and As 2p for the conduction band, and Co 3d and As 2p for the valence band without SOC effects. With SOC, Co 5d, Zr 8d, and As 3p dominated the conduction band, while Co 3d and As 3p dominated the valence band. The lattice constant showed a 0. 063% decrease with the SOC effects, which is better aligned with the experimental observations. ZrCoAs demonstrated ductility, mechanical stability, and dynamical stability. The optical properties were found to be excellent for photovoltaic applications, suggesting its potential in solar energy conversion technology. This study provides valuable information on ZrCoAs and presents opportunities for its use in solar cells, optoelectronic devices, and thermoelectric applications. The material's versatility and suitability for practical applications make it a promising candidate for further exploration in renewable energy research.

This study analyzed the behavior of three HDPE smooth geomembrane samples of 1.0, 1.5, and 2.0 mm thicknesses under heat exposure for 8760 h and the combined effect of UV radiation for 8760 h followed by heat aging for 4380 h. The results show high antioxidant consumption, an increase in viscosity, and stress cracking susceptibility, demonstrating the occurrence of cross-linking and accelerating oxidative degradation. Samples under the combined effect of UV radiation followed by heat exposure showed advanced oxidative degradation in comparison to those under heat exposure. DMA results corroborate the morphological changes in the polymer, exhibiting different thermal behavior for some types of exposure and different samples’ thicknesses.

Aim

This study aimed to fabricate and characterize Mesoporous calcium silicate nanoparticles (MCSNs) and silver-incorporated Mesoporous calcium silicate nanoparticles (Ag-MCSNs) as bioactive nanoparticles either for hybridization with contemporary endodontic materials to improve their bioactivity by using (MCSNs) as a drug delivery system, and to achieve both low cytotoxicity and enhanced antibacterial activity by incorporating Ag which is avery potent antibacterial agent to form (Ag-MCSNs) as new multifunctional materials.

Methods

The MCSNs and Ag-MCSNs nanoparticles were made using the template method. Both nanoparticles' mesoporous structure, specific surface area, pore volume, pore size, and shape were examined and characterized by FTIR, XRD, EDS, DLS, and FE-SEM. The ion release, pH change, cytotoxicity by MTT assay, and antibacterial properties against planktonic Enterococcus faecalis were further investigated by colony forming units (CFUs) counting technique.

Result

MCSNs nanoparticles were prepared and successfully incorporated with silver as Ag-MCSNs. MCSNs and Ag-MCSN nanoparticles had the characteristic mesoporous material shape and over time showed sustained ion release (Ca²⁺,Si⁴⁺ and Ag⁺) ,with an alkaline pH value (8.2–9.0). Both materials showed no obvious cytotoxicity but more cell viability with MCSNs (vitality value is >70%). Both nanoparticles showed antibacterial activity against Enterococcus faecalis (p < 0.05). With MCSNs containing Ag (Ag-MCSNs) showing higher antibacterial effect.

Conclusion

Both mesoporous calcium silicate nanoparticles (MCSNs) and mesoporous calcium silicate nanoparticles loaded with silver (Ag-MCSNs) displayed a characteristic mesoporous structure, ion release, alkaline pH, minimal cytotoxicity, and outstanding antibacterial performance with MCSNs containing Ag (Ag-MCSNs) showing higher antibacterial effect. This substance may be improved to provide a better root canal filler material, sealer, or novel intracanal medicament in dentistry.

Porous materials play a crucial role in various industrial applications, where precise determination of geometric parameters like dynamic tortuosity, as well as viscous and thermal characteristic lengths, is essential for optimizing acoustical performance. Up to this point, there has been no published size sensitivity test that recommends the ideal sample size for analyzing these parameters in an industrial environment. The present article analyzes different reconstructed porous material samples using conventional CFD and coupled FEA-CFD simulations and suggests optimal sample size and specific simulation setup optimized for industrial purposes, which grant high accuracy and reasonable computational cost. The present paper analyzed several samples, which were reconstructed by micro-CT and analyzed in Star-CCM+ simulation environment. It was found that the optimal sample size ($1.5\times 1.5\times 1.5$ mm or $2.5\times 2.5\times 2.5$ mm) is different for specific average pore sizes. It was proven through various numerical simulations based on reconstructed porous material samples that running only one coupled CFD-FEM simulation is satisfactory to directly determine all investigated parameters. It was demonstrated that the computationally demanding numerical model could be simplified in specific cases using a rigid body and highlight the limitations.

The following study presents the structural, optical, and photocatalytic properties of thin films of titanium dioxide (TiO₂) and bismuth trioxide (Bi₂O₃) in their pure state, as well as mixtures of both oxides in different atomic proportions (with respect to Ti and Bi) and as films modified with a dispersed phase of graphene oxide (GO). The films were sintered at 400 °C, 450 °C, 500 °C and 550 °C. The synthesis of the oxides was carried out by the sol-gel method and the material deposits were synthesized by the dip-coating technique. For mixtures with atomic proportions of 50% and 70% Bi₂O₃, bismuth titanates were obtained with Bi₂(Ti₂O₇) (cubic) stoichiometry at 550 °C and Bi₄Ti₃O₇ (orthorhombic) stoichiometry at 500 °C, respectively. It was determined that the Bi₂(Ti₂O₇) compound presents the best photocatalytic properties in the degradation of tartrazine in aqueous solution using solar radiation, achieving up to 30% in the photodegradation of the dye. The GO was incorporated in 2% p/p to the precursor solutions of TiO₂ and Bi₂O₃; the resulting materials presented a better photocatalytic activity.

The popularity of additively manufacturing polymers using the powder bed fusion technique, particularly polymer laser sintering has seen an unprecedented increase. As a result, numerous studies have been conducted to determine the impact of different process parameters on the physical and mechanical properties of printed parts. In addition, extensive work has also been done to optimise the process parameters to ensure that printed parts possess high qualities. However, most of these studies have only focused on the static mechanical and physical properties. In this regard, the current study aims to determine the best exposure parameters for Diapow PP MF polypropylene for different dynamic mechanical properties. It was established that the loss and storage moduli of the Diapow PP MF polypropylene material might both be subject to the volumetric laser energy density. The best process parameter set of laser power, scanning speed, layer thickness, and hatch distance for Diapow PP MF to produce printed parts with low damping and high static load carrying capacity, the respective best process parameter set is 32.9 W, 3000 mm/s, 0.15 mm, and 0.25 mm (laser energy density = 0.290 Jmm⁻³). Conversely, for high damping at room temperature, the respective best process parameter set is 32.9 W, 5000 mm/s, 0.15 mm, 0.25 mm (laser energy density = 0.146 Jmm⁻³) for laser power, scanning speed, layer thickness, and hatch distance, respectively.

Over the past decades, the number of patients with lower extremity amputation increased world-wide. The increasing rate of patients, particularly in developing countries, has led to limited access to clinics and services for prosthetic and orthotic care. Additive manufacturing has rapidly evolved over the last decade and is opening new possibilities for prosthetics and orthotics. 3D printed prosthetic sockets are a promising solution to reduce access- or cost-related barriers to prosthesis use since 3D printed prosthetic sockets can be manufactured at an affordable cost and quickly delivered to patients. We sought to compare the ultimate strength of 3D printed sockets made of different filaments (polyethylene terephthalate glycol, polycarbonate, and co-polymer polypropylene) with that of traditionally fabricated sockets (laminated composite sockets and thermoplastic sockets) and to examine whether the strength of 3D printed sockets could be improved through iterative design changes focused on reinforcing the distal end of the socket. All sockets were mechanically tested in accordance with ISO 10328 standards. Although the strength of all of the 3D printed sockets was weaker than that of laminated composite sockets, design modifications to reinforce the distal end improved the strength of 3D printed sockets made of polycarbonate and polypropylene (but not polyethylene terephthalate glycol), resulting in ultimate strengths and stiffnesses that were comparable to the traditionally fabricated thermoplastic socket. In addition, our results demonstrated that socket failure occurred mainly at the distal end regardless of material type. The strength of some 3D printed sockets under limited testing conditions showed promise to be used for clinical purpose, especially when the socket was reinforced with distal struts.

In the current study, silver/silver chloride nanoparticles (Ag/AgCl-NPs) were synthesized using the leaf extract of the endemic Lebanese plant, Origanum ehrenbergii Boiss, as the reducing medium. The structure, morphology, and physiochemical characteristics of the synthesized AgNPs were determined by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV) absorption spectroscopy, and Fourier transform infrared (FTIR) spectroscopy, and photoluminescence (PL). The antioxidant activity of the AgNPs was assessed according to the 2, 2-diphenyl−1-picrylhydrazyl (DPPH) assay. The antibacterial effect of the AgNPs was investigated using the broth microdilution method, agar well diffusion, Time-kill test, and biofilm inhibition and eradication assays. This is the first report dealing with the characterization, antioxidant, and antibacterial properties of biosynthesized Ag/AgCl-NPs using the plant Origanum ehrenbergii Boiss. The findings demonstrated the synthesis of face-centered cubic (fcc) Ag/AgCl-NPs with a mean particle size of 15 nm that displayed remarkable antioxidant capacity and inhibitory activities against eight bacteria; 3 g-positive (Enterococcus faecium, Staphylococcus aureus, and Staphylococcus haemolyticus) and 5 g-negative bacteria (Pseudomonas aeruginosa, Citrobacter braakii, Escherichia coli, Stenotrophomonas maltophilia, and Klebsiella pneumoniae). The synthesized AgNPs inhibited the growth of bacteria after 3 h. Ag/AgCl-NPs exhibited inhibitory effects on the bacterial biofilms’ formation as well as on pre-formed biofilms. These results highlight the potential to use these biosynthesized Ag/AgCl-NPs as antibacterial, antibiofilm, and antioxidant agents.