Journal of Nanoparticle Research最新文献

The study investigated processes of bimetallic copper/silver nanoparticle formation in aqueous media using two reducing agents: sodium borohydride and ascorbic acid. Adding these reducing agents in sequence allows the synthesis of bimetallic nanoparticles at room temperature. The influence of stabilizing agents such as sodium dodecyl sulfate, cetyltrimethylammonium bromide, and oleic acid and their combinations on the composition of nanoparticles in suspensions and the stability of suspensions was examined. When using a combination of oleic acid and sodium dodecyl sulfate, bimetallic copper/silver nanoparticles with a preset composition of 4:1 were formed. These nanosized systems remain stable for at least 3 months. The proposed synthetic method allows the fabrication of copper/silver nanoparticles ranging in size from 30 to 40 nm. The studied nanoparticles were shown to completely inhibit the colony growth of E. coli and S. aureus test strains on dense nutrient media when diluted to 10%, with exposure times of 3 and 5 h.

Carbon dots (CDs) have been obtained by laser ablation of charcoal in a biocompatible liquid and deposited as a thin film on a silicon substrate. A ns-pulsed Nd:YAG laser, operating at 1064 nm of wavelength, irradiates for times up to 3 h the solid carbon target placed into a phosphate-buffered saline (PBS) solution and distilled water, to prepare the CDs dispersion. The prepared thin film on silicon, under a UV lamp at 365 nm in air generates fluorescence in the visible region, with a band around 470 nm, with a blue color. Further investigations concern the thin-film irradiation using 0.8–3.0 MeV protons with 3 nA current in a vacuum, showing also fluorescence in the visible region, from about 400 up to 700 nm, as recorded by a suitable optical spectrometer. The practical applications of CDs are also presented especially in the biomedical field and in the dosimetry ambit, where they can be employed for bioimaging, diagnostics, and therapy.

The removal of Ni²⁺ ions from the effluent of the paper mill was accomplished by using magnesium ferrite nanoparticles. The nanoparticles were produced through a sol–gel process at low temperatures. Experimental factors were meticulously optimized to enhance the adsorption process. Optimal conditions were determined to be 1.0 mL of buffer solution with a pH of 8.0, 100 mg of nano-sorbent, and mixing for 30 min. When these conditions were put to test, the removal efficiency was enhanced to ≥ 98.4%. Additionally, it was discovered that the nanoparticles exhibit exceptional reusability upon regeneration after the first use. The investigation of adsorption equilibrium was conducted utilizing the Langmuir, Freundlich, and Sips models. The Sips isotherm demonstrated the strongest correlation with the experimental results, as indicated by the coefficient of determination (R²) of 0.9976 while the reaction order was estimated as 1.61 by the kinetic model.

Lung cancer is the leading cause of cancer-related deaths, worldwide. To date, various strategies have been developed and examined for treating lung cancer. The era of nanotechnology has opened a new avenue for designing advanced nanoparticulate systems for single or multiple delivery of chemotherapeutics. Despite the promising synergism between these systems, some challenges still remain. Therefore, various combination therapies based on nanostructures are developed to alleviate the drawbacks of conventional systems. These combinations may or may not have synergistic therapeutic effects. It has been observed that using combination therapies could result in a higher rate of response to treatment when compared with each modality alone. While these nanotechnological routes demonstrate promising therapeutic potentials, still some challenges such as manufacturing scalability, stability under physiological conditions, and ability to clinical translation remain unsolved. These therapies not only moderate the symptoms of the disease but also are useful for cure. It is worth noting that performing various combinations of therapies based on the symptoms, stage, and type of lung cancer could have better therapeutic outcomes than single therapies. Therefore, these kinds of treatments are proposed for clinical lung cancer treatment.

Currently, iron oxide nanoparticles around 25–30 nm in diameter are the standard magnetic tracers used for magnetic particle imaging (MPI) applications. Compared to iron oxide nanoparticles, less research has been performed in creating pure iron nanoparticles for MPI applications. Previous studies have created iron core–iron oxide shell nanoparticles around 15 nm in diameter, but in order to achieve optimal MPI signal similar to iron oxides, larger diameters around 20 nm are needed. However, due to the strong magnetic characteristics of pure iron, synthesizing pure iron nanoparticles above 15 nm in diameter can be challenging due to the high risk of agglomeration. Therefore, an investigation into creating 20-nm-sized iron nanoparticles was performed utilizing potential surfactants that might prevent agglomeration. A thermal decomposition of iron pentacarbonyl was performed with different surfactants including decylamine (DA), dodecylamine (DDA), hexadecylamine (HDA), octadecylamine (ODA), and dioctyldecylamine (DODA) to determine potential differences in size or composition. All surfactants possessed a linear structure and only varied in alkyl-chain length. From the results, it was found that longer alkyl-chain length surfactants assisted in creating larger iron nanoparticle sizes.

The consumption of fossil fuels as non-renewable energy sources has been rising, posing significant threats to both human life and the environment. Currently, the research focuses on addressing the high energy demands of modern society. Supercapacitors have garnered considerable attention drawn because of their exceptional features such as high power density, reliable long cycle stability, rapid charge/discharge capabilities, and environmentally friendly nature. Supercapacitor performance depends significantly on the large surface area of electrode materials and the characteristics of the electrolyte. Renowned for its outstanding potential as an electrode material, graphene is highlighted in this review, particularly when combined with TMOs such as Ru, Co, Ni, and Mn. This study explores TMOs with various nanocomposites emphasizing their roles in supercapacitor electrodes and detailing the charge/discharge mechanisms. It also highlights current trends and potential future research avenues to enhance the performance of next-generation supercapacitor devices.

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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.