Search Results (9,602)

Background/Objectives: Metallic NPs have been explored for various therapeutic uses owing to utilitarian physicochemical characteristics such as antibacterial, anti-inflammatory, and healing properties. The objective of this study is to evaluate the therapeutic potential of novel silver carbonate nanostructures in promoting wound healing and their antibacterial activity against Pseudomonas chengduensis and Staphylococcus aureus. Methods: In this work, we prepared Ag₂CO₃ nanoparticles through a two-step methodology that was expected to improve the material’s biomedical performance and biocompatibility. The characterization and assessment of synthesized NPs biocompatibility were conducted using hemolysis assays on the blood of a healthy male human. Further, we performed molecular docking analysis to confirm interactions of silver NPs with biological molecules. Results: In detail, the synthesized NPs showed <5% hemolysis activity at various concentrations, confirming their therapeutic applicability. Additionally, the NPs had good metabolic activities; they raised the T3/T4 hormone content and acted effectively on Insulin-like Growth Factor 1 (IGF-1) in diabetic models. They also facilitated the rate of repair by having the diabetic wounds reach 100% re-epithelialization by day 13, unlike the control group, which reached the same level only by day 16. The synthesized Ag₂CO₃ NPs exhibited high antimicrobial potential against both Pseudomonas chengduensis and Staphylococcus aureus, hence being a potential material that can be used for infection control in biomedical tissue engineering applications. Conclusions: These findings concluded that novel synthesis methods lead to the formation of NPs with higher therapeutic prospects; however, studies of their metaphysical and endocrinological effects are necessary. Full article

Recently, the quest for high-Tc superconductors has evolved from the trial-and-error methodology to the growth of nanostructured artificial high-Tc superlattices (AHTSs) with tailor-made superconducting functional properties by quantum design. Here, we report the growth by molecular beam epitaxy (MBE) of a superlattice of Mott insulator metal interfaces (MIMIs) made of nanoscale superconducting layers of quantum confined-space charge in the Mott insulator La₂CuO₄ (LCO), with thickness L intercalated by normal metal La_1.55Sr_0.45CuO₄ (LSCO) with period d. The critical temperature shows the superconducting dome with Tc as a function of the geometrical parameter L/d showing the maximum at the magic ratio L/d = 2/3 where the Fano–Feshbach resonance enhances the superconducting critical temperature. The normal state transport data of the samples at the top of the superconducting dome exhibit Planckian T-linear resistivity. For L/d > 2/3 and L/d < 2/3, the heterostructures show a resistance following Kondo universal scaling predicted by the numerical renormalization group theory for MIMI nanoscale heterostructures. We show that the Kondo temperature, T_K, and the Kondo scattering amplitude, R_0K, vanish at L/d = 2/3, while T_K and R_0K increase at both sides of the superconducting dome, indicating that the T-linear resistance regime competes with the Kondo proximity effect in the normal phase of MIMIs. Full article

Artificial bio-nanocoatings, primarily composed of proteins, offer a broad range of applications across various fields thanks to their unique properties. Proteins, as major components of these structures, enable a high degree of customization, such as mutations, conjugation with other molecules or nanoparticles, or the inclusion of an enzymatic activity. Their ability to self-assembly simplifies the production of bio-nanocoatings, making this process efficient and environment-friendly. Despite these advantages, a comprehensive understanding of the underlying self-assembly mechanism is lacking, and the reaction rates governing this process have not been characterized. In this article, we introduce a novel method to determine the key parameters describing the self-assembly mechanism of bio-nanostructures. For the first time, this approach enables an accurate calculation of the autocatalytic and self-inhibitory parameters controlling the process. Through mathematical modeling, our method enhances the understanding of how the protein-based nanocoatings form and opens new avenues for their application in nanotechnology and synthetic biology. Improved control over the self-assembly processes may enable the development of nanomaterials optimized for specific functions, such as drug delivery, biosensing, and bioactive surface fabrication. Full article

Enhancing the thermal conductivity of fluids by using nanoparticles with outstanding thermophysical properties has acquired significant attention for heat-transfer applications. Nanofluids have the potential to optimize energy systems by improving heat-transfer efficiency. In this study, cobalt ferrite nanoparticles clusters with controlled mean sizes ranging from 97 to 192 nm were synthesized using a solvothermal method to develop novel nanofluids with enhanced thermal conductivity. These clusters were comprehensively characterized using transmission electron microscopy, X-ray diffraction, Raman spectroscopy, vibrating-sample magnetometry, and nitrogen physisorption. The CoFe₂O₄ cluster nanofluids were prepared using the two-step method with various base fluids (water, propylene glycol, and a mixture of both). Dynamic light scattering analyses of the average Z-size of the dispersed nanoadditives over time revealed that the stability of the dispersions is influenced by cluster size and the proportion of glycol in the base fluid. The thermal conductivity of the base fluid and nine different 0.5 wt% CoFe₂O₄ cluster nanofluids was measured using the transient hot wire method at temperatures of 293.15, 303.15, and 313.15 K, showing different temperature dependencies. The study also explores the relationships between the thermal conductivity, cluster size, and specific surface area of the nanoadditives. A maximum thermal conductivity enhancement of 4.2% was reported for the 0.5 wt% nanofluid based on propylene glycol containing 97 nm CoFe₂O₄ clusters. The findings suggest that the specific surface area of nanostructures is a more relevant parameter than size for describing improvements in thermal conductivity. Full article

Friction is ubiquitous in industry and daily life, which not only leads to the wear and tear of equipment and machinery, but also causes a lot of energy waste. Friction is one of the significant factors leading to energy loss in mechanical systems. Therefore, it is essential to minimize friction losses. Creatures in nature have evolved various surfaces with different tribological characteristics to adapt to the environment. By studying, understanding, and summarizing the friction and lubrication regulation phenomena of typical surfaces in nature, various bionic friction regulation theories and methods are obtained to guide the development of new lubrication materials and lubrication systems. This article primarily discusses the study of lubrication mechanisms through biomimetic design, which is mainly divided into chemical approaches, structural strategies, and chemical–structural coupling approaches. From the chemical point of view, this paper mainly summarizes joint lubrication and engineering lubrication in biomedicine, with inspiration from lotus leaves, fish skin, and snake skin, each with unique antifriction structures which are famous for their super hydrophobicity in nature. Finally, chemical–structural coupling simulates the lubrication mechanism of natural organisms from the joint action of biological structures and chemical substances, and is applied to coating design, so as to reduce the friction and wear on coating surfaces, improve the durability and anti-pollution ability of coatings, significantly improve the tribological performance of mechanical systems, promote scientific innovation, and promote energy conservation, emission reduction, and sustainable development. Full article

With the inherent demand for hydrophobic materials in processes such as membrane distillation and unidirectional moisture conduction, the preparation and application development of profiles such as modified cellulose acetate membranes that have both hydrophobic functions and biological properties have become a research hotspot. Compared with the petrochemical polymer materials used in conventional hydrophobic membrane preparation, cellulose acetate, as the most important cellulose derivative, exhibits many advantages, such as a high natural abundance, good film forming, and easy modification and biodegradability, and it is a promising polymer raw material for environmental purification. This paper focuses on the research progress of the hydrophobic cellulose acetate preparation process and its current application in the water-treatment and resource-utilization fields. It provides a detailed introduction and comparison of the technical characteristics, existing problems, and development trends of micro- and nanostructure and chemical functional surface construction in the hydrophobic modification of cellulose acetate. Further review was conducted and elaborated on the applications of hydrophobic cellulose acetate membranes and other profiles in oil–water separation, brine desalination, water-repellent protective materials, and other separation/filtration fields. Based on the analysis of the technological and performance advantages of profile products such as hydrophobic cellulose acetate membranes, it is noted that key issues need to be addressed and urgently resolved for the further development of hydrophobic cellulose acetate membranes. This will provide a reference basis for the expansion and application of high-performance cellulose acetate membrane products in the environmental field. Full article

In this paper, platinum nanoparticles with a size of less than 50 nm were rapidly and successfully synthesized in low-temperature molten salt using a microwave method. The morphology and structure of the product were characterized by SEM, TEM, EDX, XRD, etc. The TEM and SEM results showed that the prepared product was a nanostructure with concave and uniform size. The EDX result indicated that the product was pure Pt, and the XRD pattern showed that the diffraction peaks of the product were consistent with the standard spectrum of platinum. The obtained Pt/C nanoparticles exhibited remarkable electrochemical performance in a formic acid catalytic oxidation reaction (FAOR), with a peak mass current density of 502.00 mA·mg⁻¹_Pt and primarily following the direct catalytic oxidation pathway. In addition, in the chronoamperometry test, after 24 h, the mass-specific activity value of the Pt concave NPs/C catalyst (10.91 mA·mg⁻¹_Pt) was approximately 4.5 times that of Pt/C (JM) (2.35 mA·mg⁻¹_Pt). The Pt/C NPs exhibited much higher formic acid catalytic activity and stability than commercial Pt/C. The microwave method can be extended to the preparation of platinum-based alloys as well as other catalysts. Full article

The structure and magnetic properties of epitaxial Heusler alloy films (Co₂FeGe) deposited on MgO (100) substrates were investigated. Films of 60 nm thickness were prepared by magnetron co-sputtering at different substrate temperatures (T_S), and those deposited at room temperature were later annealed at various temperatures (T_a). X-ray diffraction confirmed (001) [110] Co₂FeGe || (001) [100] MgO epitaxial growth. A slight tetragonal distortion of the film cubic structure was found in all samples due to the tensile stress induced by the mismatch of the lattice parameters between Co₂FeGe and the substrate. Improved quality of epitaxy and the formation of an atomically ordered L2₁ structure were observed for films processed at elevated temperatures. The values of magnetization increased with increasing T_S and T_a. Ferromagnetic resonance (FMR) studies revealed 45° in-plane rotation of the easy anisotropy axis direction depending on the degree of the tetragonal distortion. The film annealed at T_a = 573 K possesses the minimal FMR linewidth and magnetic damping, while both these parameters increase for another T_S and T_a. Overall, this study underscores the crucial role of thermal treatment in optimizing the magnetic properties of Co₂FeGe films for potential spintronic and magnonic applications. Full article

Innovative methods for substrate patterning provide intriguing possibilities for the development of devices based on ordered arrays of semiconductor nanowires. Control over the nanostructures’ morphology in situ can be obtained via extensive theoretical studies of their formation. In this paper, we carry out an investigation of the ordered nanowires’ formation kinetics depending on the growth mask geometry. Diffusion equations for the growth species on both substrate and nanowire sidewalls depending on the spacing arrangement of the nanostructures and deposition rate are considered. The value of the pitch corresponding to the maximum diffusion flux from the substrate is obtained. The latter is assumed to be the optimum in terms of the nanowire elongation rate. Further study of the adatom kinetics demonstrates that the temporal dependence of a nanowire’s length is strongly affected by the ratio of the adatom’s diffusion length on the substrate and sidewalls, providing insights into the proper choice of a growth wafer. The developed model allows for customization of the growth protocols and estimation of the important diffusion parameters of the growth species. Full article

Traditional sunscreens have relied on synthetic compounds to protect against harmful ultraviolet (UV) radiation. However, there is increasing interest in utilizing the natural photoprotective properties of microalgae extracts. This approach does not only aim to enhance the stability and efficacy of sun protection formulae but also seeks to reduce the reliance on synthetic sunscreens. This study investigates the encapsulation of Tisochrysis lutea extract (TL) in nanostructured lipid carriers (NLCs) to create a combination (NLC-TL) with enhanced physicochemical stability, antioxidant activity, SPF efficacy, wound healing capacity, and skin hydration. The particle size and ζ-potential were approximately 100 nm and −50 mV, respectively, and both formulations successfully passed the stability tests. The antioxidant activity, measured via DPPH assay, revealed that NLC-TL achieved the highest free radical scavenging activity across all tested concentrations, indicating a synergistic effect. The incorporation of TL in NLCs maintained the sun protection factor (SPF) of a 2% extract solution (1.53 ± 0.13). The wound healing assay indicated that NLC-TLs significantly enhanced wound closure compared to controls and TL alone. Additionally, skin hydration tests on healthy volunteers revealed that NLC-TLs provided superior and sustained hydration effects. These results highlight NLC-TLs’ potential as a multifunctional topical agent for cosmetic and therapeutic applications. Full article

Micro- and nano-structures of ZnO were synthesized by the vapor–solid method at 600, 700, and 800 °C in atmospheres of Ar and air, at atmospheric pressure. The structural characterization XRD shows that the nano-structures synthesized in air atmosphere at 600 °C, while diffraction peaks were found due to Zn because the presence of metallic Zn remains on the surface of the pellet. SEM images show that the morphologies range from nano-wires to micro-tubes. When cathodoluminescence is measured in micro-tubes, there is a shift of the near-band edge of the ZnO toward red; this is due to structural defects in the ZnO network. This result is corroborated with panchromatic CL measurements, which exhibit a difference in brightness between the micro-tubes. Furthermore, EDS measurements show an atomic quantity ratio of Zn:O that differs from the stoichiometric composition in the micro-tubes. The photocatalytic activity of three types of structures—nano-wires, micro-tubes, and micro-rods under UV irradiation using methylene blue as a model pollutant—were evaluated. The best response was obtained for nanowires, not only because they have a larger surface area but also because of the present defects. Full article

Lithography serves as a fundamental process in the realms of microfabrication and nanotechnology, facilitating the transfer of intricate patterns onto a substrate, typically in the form of a wafer or a flat surface. Grayscale lithography (GSL) is highly valued in precision manufacturing and research endeavors because of its unique capacity to create intricate and customizable patterns with varying depths and intensities. Unlike traditional binary lithography, which produces discrete on/off features, GSL offers a spectrum of exposure levels. This enables the production of complex microstructures, diffractive optical elements, 3D micro-optics, and other nanoscale designs with smooth gradients and intricate surface profiles. GSL plays a crucial role in sectors such as microelectronics, micro-optics, MEMS/NEMS manufacturing, and photonics, where precise control over feature depth, shape, and intensity is critical for achieving advanced functionality. Its versatility and capacity to generate tailored structures make GSL an indispensable tool in various cutting-edge applications. This review will delve into several lithographic techniques, with a particular emphasis on masked and maskless GSL methods. As these technologies continue to evolve, the future of 3D micro- and nanostructure manufacturing will undoubtedly assume even greater significance in various applications. Full article

It is expected that two-dimensional (2D) metal nitrides (MNs) consisting of the 13th group elements of the periodic table and nitrogen, namely aluminium nitride (AlN), gallium nitride (GaN), indium nitride (InN) and thallium nitride (TlN), have enhanced physical and mechanical properties due to the honeycomb, graphene-like atomic arrangement characteristic of these compounds. The basis for the correct design and improved performance of nanodevices and complex structures based on 2D MNs from the 13th group is an understanding of the mechanical response of their components. In this context, a comparative study to determine the elastic properties of metal nitride nanosheets was carried out making use of the nanoscale continuum modelling (or molecular structural mechanics) method. The differences in the elastic properties (surface shear and Young’s moduli and Poisson’s ratio) found for the 2D 13th group MNs are attributed to the bond length of the respective hexagonal lattice of their diatomic nanostructure. The outcomes obtained contribute to a benchmark in the evaluation of the mechanical properties of AlN, GaN, InN and TlN monolayers using analytical and numerical approaches. Full article

In the field of modern optical computing and communication, optical bistability plays a crucial role. With a weak third-order nonlinear coefficient, low switch thresholds of optical bistability from Si-based nanophotonic structures remain a challenge. In this work, a metasurface consisting of silicon nanostrip arrays placed on the optically thick silver film is proposed. The light–matter interaction is enhanced by mirror-inducing the magnetic anapole states (MASs) and asymmetrically optimizing its silicon nanostrip. Numerical results show that the average enhancement factor (EF) of an electric field can be greatly enhanced to be 1524.8. Moreover, the optical bistability of the proposed metasurface achieves the thresholds of I_ON-OFF and I_OFF-ON of 8.5 MW/cm² and 7.1 MW/cm², respectively, which is the lowest threshold when compared to the previous works based on silicon nanostructures. The angular dependance of the bistability performance is also investigated. This work facilitates the proposed hybrid metasurface in the fields of miniaturized all-optical switches and modulators, which are key components in optical computing and communication. Full article