Journal of Nanoparticle Research最新文献

Silver nanoparticles (AgNPs) have been extensively studied due to their antimicrobial properties against several pathogenic microorganisms. A particularly promising application of these nanoparticles involves their incorporation into textiles to enhance the efficacy of face masks. This work aims to deposit AgNPs on polyamide 6,6 fabrics using a hybrid corona-dielectric barrier discharge plasma reactor and evaluate their antimicrobial effect as well as their cytotoxicity. Prior to deposition, the fabrics were activated in air plasma at atmospheric pressure. The deposition process was then initiated by nebulizing a silver nanoactive into the system by a flat cavity present in the high-voltage electrode, a distinctive feature that sets this approach apart from other AgNP deposition techniques reported in the literature. The incorporation of AgNPs on polyamide 6,6 fabric surface was confirmed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The thermal behavior of the samples was studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). To identify the crystalline phases, X-ray diffraction (XRD) analyses were performed on control (without AgNPs) and treated (with AgNPs) samples. Microbiological analysis was based on the AATCC 100–2019 test method with modifications for two different species of bacteria: Staphylococcus aureus and Klebsiella pneumoniae. Bacterial suspensions with 1–3 × 10⁵ cells/mL were inoculated into control and treated samples, followed by viable cell count (CFU/mL). Statistically significant reductions in bacterial counts were detected, with 62.37% and 74.63% reduction percentages compared to the control sample for Staphylococcus aureus and Klebsiella pneumoniae, respectively. Furthermore, cytotoxicity analysis, performed according to ISO 10993–5/2009, showed that the treated fabrics are not cytotoxic due to higher viability than 70%.

Magnesium’s high storage capacity, with a theoretical value of about 7.6 wt.%, makes it a viable candidate for hydrogen storage. However, slow kinetics and strong thermodynamic stability lead to a rather high desorption temperature, usually above 350 °C. It has been demonstrated that nanosizing magnesium-based materials is a successful strategy for simultaneously improving the kinetic and thermodynamic characteristics of MgH₂ during hydrogen absorption and desorption. MgH₂ nanoparticles were obtained by microwave assisted synthesis. To the best of our knowledge, synthesis of MgH₂ nanoparticles by this method has not been reported. It was possible to produce MgH₂ nanoparticles smaller than 20 nm. MgO and Mg(OH)₂ were also present in the produced nanoparticles, although these compounds may enhance the processes involved in the release and absorption of hydrogen.

Perovskite hydroxystannate (MSn(OH)₆) has garnered considerable interest in recent years as a novel flame retardant characterized by its low toxicity and environmentally benign properties. In order to improve the flame retardancy and smoke suppression properties of epoxy resin (EP) matrices, transition metal hydroxystannate (MSn(OH)₆, M = Fe, Co, Mn) was prepared by a ultrasonic-coprecipitation method and used as flame retardants. The synthesized composites were assessed for their flame retardant characteristics and mechanical properties through the measurement of the limiting oxygen index (LOI), the cone calorimetry test (CCT), and universal tensile testing. Upon the incorporation of 10 wt% of the MSn(OH)₆ flame retardants, the flame retardant of EP composites exhibited marked enhancement, especially manganese hydroxystannate (MHS). Compared with pure EP, the EP/MHS-10 composite demonstrated the best performance, reducing the peak of heat release rate (pHRR), total heat release (THR), total smoke production (TSP) by 60.0%, 14.4%, and 32.6%, respectively. During the process of combustion, the decomposition of MSn(OH)₆ results in the generation of non-flammable gases and water vapor. In the condensed phase, tin (Sn) and transition metals contribute to the formation of a more protective char residue. The residue serves as a physical barrier, effectively isolating the underlying epoxy (EP) matrix material from heat and oxygen.

This paper utilized molecular dynamics simulations to explore how grain size and temperature impact the mechanical characteristics of Fe-Bi nano-polycrystalline complexes. It was determined that the Hall–Petch relationship has a critical grain size of 10 nm, with a corresponding maximum flow stress of 2.58 GPa. In specimens where d exceeds 10 nm, the average rheological stress rises as d decreases, in line with the Hall–Petch relationship because of grain boundary fractures resulting from dislocation slips and deformation twinning. For specimens with d less than 10 nm, the change in rheological stress with respect to d aligns with the inverse Hall–Petch relationship, which is attributable to grain rotation and grain boundary migration. Moreover, as the temperature goes up, the proportion of atoms at the grain boundaries steadily increases, while that within the grains gradually diminishes. With the growth of atomic disorder, melting takes place at the grain boundaries. These discoveries hold favorable implications for the design of bismuth-based free-cutting steels.

This study evaluated the CH₄, CO, H₂, NH₃, and NO–sensing abilities of Al₁₂C₁₂ nanocages by using density functional theory. The geometry optimisation, cohesive energy, adsorption energy, and other electronic properties of Al₁₂C₁₂ nanocages and complexes after gas adsorption were calculated. The Al₁₂C₁₂ nanocage is highly symmetric and consists of eight hexagonal and six tetragonal rings. The Al₁₂C₁₂ nanocage had a cohesive energy of 4.6 eV and an energy gap of 1.593 eV, indicating that Al₁₂C₁₂ nanocages are stable and have semiconductor-like properties. The gas that the Al₁₂C₁₂ nanocage most effectively adsorbed was NH₃. The NH₃ complex not only had largest adsorption energy and shortest adsorption distance but also transferred the most charges and had the largest dipole moment. Mulliken charge transfer theory and molecular electrostatic potential analyses were used to evaluate charge transfer and distribution. The charge distribution of the Al₁₂C₁₂ nanocage differed depending on the type of gas, with NH₃ resulting in the greatest number of charges being transferred. Density of states analysis was performed, and the results indicate that the complex was primarily composed of 3p orbitals of C and Al. The highest occupied molecular orbital and lowest unoccupied molecular orbital were analysed. Interactions with various gases significantly reduced the energy gap values of pure nanocages, and those of the NH₃ and NO complexes were significantly reduced because of changes in the 3p orbitals of the C and Al atoms. This study demonstrates that pure Al₁₂C₁₂ nanocages have potential as materials for the detection of NH₃ and NO gas.

In this study, pure TiO₂ and 5 wt% BaTiO₃ nanocomposites were synthesized using the sol–gel method. The crystal structure, morphology, optical properties, and chemical composition of the synthesized nanoparticles were characterized by using XRD, SEM, HR-TEM, UV–vis spectroscopy, and XPS. The average crystallite sizes of the pure TiO₂ and 5 wt% BaTiO₃ were approximately 15.2 nm and 8 nm, respectively. Particle size is affected by the nature of the surfactant. Spherically shaped nanoparticles with aggregation and a homogeneous size distribution were observed using SEM and HR-TEM. The bandgap was determined to be 3.24 eV and was found to have excellent optical behavior. The chemical and electronic states of the BaTiO₃ nanoparticles were determined by XPS. The nanoparticles photocatalytically degraded the Congo red dye in an aqueous solution. Compared to pure TiO₂ nanoparticles, 5 wt% BaTiO₃ nanoparticles with surfactant assistance demonstrated better photocatalytic activity.

The silicon-gallium system’s nano-phase diagram, which takes into account the shape influence of the nanoparticles, has been evaluated for the first time using phase equilibrium and thermodynamic data. By using suitable thermodynamic models for the computation of the thermodynamic parameters, the impact of grain size has been taken into account. Ga nanoalloy has been studied in a variety of shapes, including icosahedral, spherical, hexahedral, octahedral, tetrahedral, film, and wire. The findings have been contrasted with data and empirical values from earlier research. It has been noted that thermodynamic characteristics such as the eutectic temperature, eutectic composition, and melting temperature of Si and Ga drop as particle size in the Ga–Si system decreases. The melting temperature of the nanoparticles is significantly influenced by the dimensions of the nanomaterials. The current work has made use of the dimension-based surface particle concentration, the total number of particles, and their relationship. Dimension of nanoparticles is important for analyzing their thermodynamic properties and phase diagram, in addition to their size.

The present research focuses on synthesizing and characterizing sulfur-doped Zinc oxide (S-ZnO) nanoparticles (NPs) utilizing an economical, simple, cost-effective, and solution-free thermo-mechanical technique. The antibacterial activity of these nanoparticles against Klebsiella pneumoniae and their efficiency in the photocatalytic degradation of the pollutant 2,4-dichlorophenol are assessed. Powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the crystallite size and morphological features, respectively. XRD results for S-ZnO NPs with concentrations of 3 wt%, 5 wt%, and 7 wt% showed crystallite sizes of 14.51 nm, 11.33 nm, and 10.14 nm, respectively. FE-SEM shows the morphology of pristine ZnO as rod-shaped and when sulfur is doped in ZnO, it shows tube-shaped morphology. The band gap values for pristine ZnO and 5 wt% S-ZnO NPs were 3.02 eV and 2.82 eV, respectively, highlighting the enhanced photocatalytic potential of the doped nanoparticles. Pristine ZnO and 5 wt% S-ZnO NPs have surface areas of 30.86 m²/g and 39.77 m²/g, respectively. Photocatalytic studies demonstrated that 5 wt% S-ZnO NPs exhibit superior photocatalytic activity, achieving 92% degradation of 2,4-dichlorophenol in an aqueous medium within 60 min at a concentration of 0.8 mg/mL under natural sunlight. Scavenger tests using histidine and ascorbic acid confirmed that hydroxyl radicals (⋅OH) played a key role in pollutant breakdown. The reusability of S-ZnO NPs revealed stability over three cycles. Antibacterial tests using the disc diffusion method against Klebsiella pneumoniae indicated that 5 wt% S-ZnO had stronger antibacterial effects than pristine ZnO, making it promising for environmental remediation and biomedical applications.

Cancer is known to be among the biggest health issues of nowadays, as its therapy has become increasingly more complicated due to drug-resistant tumors. This means that medicine may potentially become ineffective in specific cases, which can result in dire circumstances for the patient. Therefore, research for alternative ways of combating drug resistance has taken the front seat recently. Metal nanoparticles (NPs) have shown promise in addressing issues commonly observed in traditional chemotherapy, such as drug resistance. These tiny metal particles are known to greatly contribute to cancer treatment by enhancing targeting capabilities, silencing genes, and delivering medication more effectively. Additionally, metal NPs that have been modified with targeting molecules allow for greater precision in delivering energy to tumors. Specifically, the nanomedicine usage to fight against cancer has grown in popularity. The various factors that contribute to the inability of cancer drugs to effectively kill cancer cells include increased levels of drug transporters that remove the drugs, faulty pathways for cellular death, and low oxygen levels. The use of nanoparticles designed to specifically target and overcome these mechanisms has the potential to significantly improve the ability to reverse multidrug resistance in cancer treatment. Through the development of tailor-made nanoparticles having ligands which binds to drug-resistant cancer cells, the unwanted uptake of drugs in other parts of the body is minimized and improved targeting is facilitated. Studies have found that metallic nanostructures can be employed to examine sensitivity to therapy and cancer resistance. The use of metal NP therapeutic systems not only offers the ability to diagnose and treat simultaneously, but also enables precise and directed drug release. This has the potential to greatly transform the way cancer is treated and managed. Therefore, various metal nanoparticles can be considered possible chemotherapeutic options. Moreover, with the growing understanding of various drug resistance mechanisms in tumors, there is a rising focus on creating NPs specifically designed to combat these mechanisms.

Paper deacidification is one of the most important tasks in the conservation of cultural relics. Recently, fluorocarbon solvents which are safe, environment-friendly, and do not react with paper have attracted extensive attention and have been used as the deacidification solvent. However, as one of the most commonly used deacidification agents, the poor dispersibility of nano-MgO in organic solvent has greatly restricted the paper deacidification effect. Herein, by introducing polyvinylpyrrolidone (PVP, K30) as a guiding agent during the process of nano-MgO electrolysis synthesis, we enhanced the dispersibility of nano-MgO in fluorocarbon solvent (C₅H₃F₉O) with stable suspension time extended to 1.5 h, then optimized deacidification performance of paper in Qing Dynasty. The nano-MgO immobilized with PVP (MgO/PVP) is flaky. Compared with MgO synthesized directly without surfactant, its suspension stability increased from 30 min to 1.5 h. Moreover, nano-MgO immobilized with PVP exhibited the best paper deacidification effect. Other than pH 7.8 and 7.9 in groups of MgO and MgO-PVP (PVP addition after MgO synthesis), the pH of the paper after deacidification reached 8.85 for MgO/PVP. In addition, tensile strength of the treated paper is increased 16.3% and the color of the paper is slightly influenced. Overall, We have improved the electrolysis method, and realized the uniform dispersion of nano-MgO in fluorocarbon solvent, which brought the good deacidification effect to the paper and had certain significance in the protection of cultural relics.

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