Next Nanotechnology最新文献

By the semipolar blue single GaN μ-LED and blended Ir(piq)2(acac) + CC-MP5 polymer thin film color converter, a high-speed white-light μ-LED-based system is built up for the applications of short-distance VLC. The characteristics and properties of both devices are analyzed to understand the requirements for transmission and illumination. By selecting the growing orient, the influence of QCSE is reduced in this GaN μ-LED. Meanwhile, possessing the low reflection characteristic, it is beneficial for signal modulation. For the polymer thin film color converter with a lifetime of 7.8 ns, low surface reflection and high conversion efficiency are thought of good properties. Color-converted cool white light has a CCT of around 7000 K and high color accuracy with a CRI of about 90. The APD-combined frequency responses of the GaN μ-LED and GaN μ-LED + polymer are measured as 750 MHz and 600 MHz, respectively. After the optimization by utilizing the adaptive SNR-flattening pre-emphasis algorithm, the transmission performance of the white-light μ-LED is significantly promoted. For NRZ-OOK encoding, a 1.4 Gbps 0.15-m free-space transmission is achieved with a rising time of 656.33 ps, a falling time of 493.32 ps, and a Q-factor of 4.75. Besides, in more advanced data formats, the performance of this white-light μ-LED can be better highlighted. For the same 0.15-m free-space VLC, a high-speed 3 Gbps broadband 8-QAM-OFDM transmission is fulfilled with an EVM of 23.9%, an average SNR of 12.5, and a BER below 3.8 × 10^-3; while to the best of our knowledge, a record 3.5 Gbps BL-DMT transmission is implemented as well. This white-light μ-LED can also be integrated into large-scale arrays for multi-functional VLC applications.

Au nanostructures offer a wide range of applications such as surface-enhanced Raman spectroscopy, photovoltaics, and biosensors. Effective integrating well-controlled Au nanostructures on chip via a self-assembly process remains challenging as most of the Au nanostructures were prepared by either chemical synthesis methods or lithography patterning techniques. This study introduces a simple two-step approach for fabricating Au nanostructures on substrate with well controlled morphology and density. First, epitaxial Au-Sr₃Al₂O₆ (SAO) vertically aligned nanocomposites (VANs) were deposited on SrTiO₃ substrates. Second, by subsequently dissolving the water-soluble SAO matrix, various Au nanostructures ranging from 0D nanoparticles to 1D nanopillars are demonstrated. The Au morphology tuning is achieved by varying the deposition parameters of the VANs. This method eliminates the need of harsh chemical solutions and tedious lithography/patterning steps. These findings provide a novel strategy for tailoring the Au nanostructures and their optical properties, and, demonstrating on-chip integration for advanced optical device applications.

Mechanistic insights into the interfacial evolution are essential for advancing rechargeable zinc metal batteries (RZMBs). Employing in situ atomic force microscopy (AFM), we observed the Zn plating and stripping processes on the Zn metal anode and investigated the effect of initial stripping over the interfacial evolution. During the initial stripping process, the interfacial evolution is uneven, and by-products form at the Zn anode, which contributes to the heterogeneous nucleation and quick dendrite growth during the subsequent plating, causing performance fading. In contrast, uniform Zn deposition and reversible dissolution can be achieved during the initial plating and following stripping processes. The Zn substrate remains flat without evident cracks or pits, which ensures the interfacial stability of the Zn metal anode during cycling. This work provides direct insights into the morphological evolution and interfacial mechanism of Zn metal anode, promoting the optimal design of advanced RZMBs.

Biological routes of nanoparticle synthesis, especially the use of plant-based extracts, have shown great potential for the production of silver nanoparticles (Ag NPs). Ag NPs synthesized in this way is a simple one-step method that is economical and environmentally friendly. With the increasing need to develop new and effective antibacterial agents, a novel and stable Ag NPs is synthesized using aqueous seed extract of Strychnos potatorum (SP). Ag NPs obtained at room temperature (S1) and under optimal microwave irradiation (S2) were compared in the present work. The as-synthesized Ag NPs are characterized by Ultraviolet-Visible (UV-Vis) spectroscopy, X-Ray Diffraction (XRD), Fourier Transform Infrared (FT-IR) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM). UV-Vis spectra showed Surface Plasmon Resonance (SPR) peaks at 430 nm (S1) and 438 nm (S2) associated with the formation of Ag NPs. XRD patterns indicate the crystallinity of Ag NPs, with an average crystallite size of approximately 23 nm (S1) and 15 nm (S2). FT-IR study revealed potential biomolecules to form Ag NPs. FESEM and TEM analysis revealed the spherical shape of Ag NPs. An average particle size of approximately 31 nm (S1) and 19 nm (S2) was revealed from TEM analysis. To the best of our understanding, this study is novel as Ag NPs synthesized from SP using a microwave oven are described in detail for the first time. The study also demonstrated the potential of Ag NPs for antibacterial effect against Gram-positive bacteria (Streptococcus pneumoniae, Staphylococcus aureus) and Gram-negative bacteria (Klebsiella pneumoniae, Vibrio vulnificus). Our findings show that at a specific concentration, small NPs are more efficient in inhibiting bacterial activity. This research indicates that Ag NPs synthesized from SP exhibit strong antibacterial activity for the treatment of bacterial infection.

This study investigated the encapsulation of propranolol hydrochloride drug using nanoliposome coatings prepared by a magnetic stirring method. The encapsulation efficiency was determined using a UV–vis spectrophotometer, and the morphology of the propranolol-loaded liposomes was examined by electron microscopy. The results showed that propranolol hydrochloride can be effectively encapsulated in liposomes with a capsule percentage exceeding 70 %. The composition of the lipids used in the liposome structure played a crucial role in the solubility of the encapsulated drug. The relatively good solubility of propranolol allowed for its better entrapment within the aqueous part of the liposomes. The encapsulation of propranolol hydrochloride within liposomal coatings is expected to improve the stability of the drug in the body and significantly reduce its release until it reaches the target organ. The prepared liposomes exhibited a particle diameter between 20 and 100 nm, making them suitable for intravenous drug delivery. The findings suggest that nanoliposome coatings are a promising strategy for the controlled delivery of propranolol hydrochloride.

Silver nanoparticles (AgNPs) have gained significant attention in recent years due to their unique physicochemical properties and wide-ranging applications. This study investigates the green synthesis of silver nanoparticles using the pathogen Shigella flexneri 29508 and evaluates their efficacy as both antioxidant and antifungal agents. The pure strain of the bacterium was identified as a potential nanoparticle producer based on its ability to reduce silver ions to nanoparticles. The formation of silver nanoparticles was confirmed by characteristic colour changes and further confirmed by UV–visible spectroscopy with SPR around 415 nm. The synthesized silver nanoparticles were characterized using various techniques, including TEM, SEM and DLS. DLS confirmed the nano-size, homogeneity and good stability of the fabricated particles TEM analysis revealed the spherical morphology of the nanoparticles, with an average size of 50 nm. SEM analysis also confirmed and supported the data. The antioxidant activity of the green-synthesized silver nanoparticles was evaluated using standard assays, and results demonstrated significant antioxidant potential, indicating the ability of the nanoparticles to neutralize free radicals and protect against oxidative stress. The bio-synthesised silver nanoparticles were also tested for their antifungal properties against two clinically relevant fungal strains. Resazurin-based micro-dilution viability assays, agar well diffusion, and spread plate assay methods were employed to determine the MIC and MBC of the nanoparticles, assessing their inhibitory effects on fungal growth. The results revealed potent antifungal activity, with varying degrees of efficacy against the tested fungal pathogens. Besides bioactivity, the cytotoxicity of the nanoparticles was also evaluated using primary cell cultures of peripheral blood cells. The bio-fabricated structures exhibited minimal toxicity and mortality, indicating their benign and eco-friendly nature in biological systems. This study highlights the successful green synthesis of silver nanoparticles using bacteria and elucidates their antioxidant, cytotoxicity, and antifungal activities. These findings contribute to the development of eco-friendly nanoparticle synthesis methods and suggest potential applications in the fields of medicine, agriculture, and environmental remediation.

Present inspection minutely explores the features of Tsallis entropy and the corresponding internal energy and heat capacity of GaAs quantum dot (QD) incorporating Gaussian impurity. Simultaneous influence of Gaussian white noise (GWHN) has also been invoked where GWHN enters the system by means of additive and multiplicative modes. The study unfolds extremely subtle interplay between temperature, entropy index, GWHN, mode of incorporation of GWHN and the particular physical parameters concerned. The resultant influence of the said interplay finally governs the traits of the Tsallis entropy-based thermal properties. The investigation manifests competitive behavior between thermal disorder and spatial disorder that prominently affects the thermal properties.

The structural color properties of colloidal arrays can be controlled by colloidal assembly via tuning the size, composition, and ordering of colloidal particles and their formation at the macroscale. Controlled assembly and patterning offer many advantages for the technological development of photovoltaics, optics, and lab-on-a-chip, where the ordering of particles can influence the properties and functions of a system. Many techniques have been well established for patterning ordered colloidal arrays (colloidal crystals), and disordered colloidal arrays (colloidal glasses). However, they are time-consuming and require additional steps such as masking, etching, or stamping. The advent of digital manufacturing, in which additive manufacturing is combined with computer-aided design (CAD), can overcome some of the challenges in fabricating structures from colloidal particles. This article presents a review of recent strategies for digitally fabricating 1D (e.g., single line), 2D (e.g., arrays of dots and patterns with lines), and 3D (e.g., dots and balls) colloidal crystals and glasses, including inkjet printing, direct ink writing, electrohydrodynamic jet printing, two-photon lithography, and digital light processing. The requirements of colloidal ink formulations for different 3D printing methods are discussed. The effects of the wettability of the printed ink on the ordering of colloidal particles in the fabricated structures and the resulting structural colors are discussed. Finally, a summary and perspective on future development are presented.

As a member of the hexagonal boron nitride (h-BN) system, boron nitride nanoribbons (BNNRs) have a BN polar covalent bonding infrastructure, and there are small-scale effects with strong correlation with piezoelectric effects as well as edge-strengthening quantum effects. However, realizing the polarization effect on BNNRs through experiments remains challenging. Here, we verify the strain-induced polarization effect on BNNRs through computational simulations and experiments. Using the ten-point iterative method, a computational model that can be used for the discrete difference of the polarization charge density and energy density of BNNRs is developed, and the correctness of the model for the polarization effect of Gaussian strain-induced BNNRs is verified by the computational programming in Python language. The polarization effects of strain-induced zigzag-edge BNNRs (ZBNNRs) for sawtooth strain, parabolic strain and oblique sawtooth strain are also investigated separately. In addition, the results of the computational simulations are experimentally verified to be consistent with the theoretical calculations. And the piezoelectric constant of − 276.88 pm∙V⁻¹ for strained ZBNNRs is found to be four times higher than that of unstrained ZBNNRs. This study provides a relevant reference for the study of realizing the high integration of nano-scale h-BN based piezoelectricity for piezoelectricity.

Metal oxide porous nanomaterials are of great interest across scientific fields due to their intriguing properties, allowing their usage from lab-scale research to industrial applications. However, the production of high surface area metal oxide nanomaterials still poses significant challenges. This study introduces a novel method for synthesizing highly porous tin oxide (SnO₂) nanostructures using carbon as the template material. The synthesis process includes the formation of a precursor composite containing resorcinol-formaldehyde gel and a tin oxide precursor, which is first carbonized to convert the resorcinol-formaldehyde into a porous three-dimensional carbon framework. This framework acts as a scaffold for the nucleation of SnO₂ nanoparticles. Subsequent oxidation selectively removes the carbon template, yielding highly porous SnO₂ nanomaterials. Electron microscopy analysis shows that the nanomaterials feature a particle size with average diameter of ∼30 nm, whereas Gas adsorption-desorption characterization indicates pronounced mesoporosity, with a pore size of 3 nm and a specific surface area of 476 m²/g. The enhanced surface area surpasses the previously reported studies on porous SnO₂. This is significant considering the easy production process of the nanomaterials, which signifies its potential for large-scale production. Furthermore, this approach offers versatility, as different materials can replace the carbon component, allowing for tailored nanostructure design and enhanced properties. The resulting materials can offer exciting possibilities in the field of materials science and nanotechnology.