Next Nanotechnology最新文献

The micro-light emitting diode (µLED) technology is poised to revolutionise display applications through the introduction of nanomaterials and Group III-nitride nanostructures. This review charts state-of-the-art in this important area of micro-LEDs by highlighting their key roles, progress and concerns. The review encompasses details from various types of nanomaterials to the complexity of gallium nitride (GaN) and III nitride nanostructures. The necessity to integrate nanomaterials with III-nitride structures to create effective displays that could disrupt industries was emphasised in this review. Commercialisation challenges and the economic enhancement of micro-LED integration into display applications using monolithic integrated devices have also been discussed. Furthermore, different approaches in micro-LED development are discussed from top-down and bottom-up approaches. The last part of the review focuses on nanomaterials employed in the production of micro-LED displays. It also highlights the combination of III-V LEDs with silicon LCDs and perovskite-based micro-LED displays. There is evidence that efficiency and performance have improved significantly since the inception of the use of nanomaterials in manufacturing these.

Bismuth titanate is widely used in various fields of science and technology due to its unique physical and chemical properties. Nanostructured metal oxide compounds of the Bi–Ti–O system, consisting of columnar TiO₂ nanostructures obtained by electrochemical anodization of a two-layer Ti/Al composition, and platelet Bi₂O₃ nanostructures formed by sequential ion-layer deposition were synthesized. Morphological changes and phase transformations in the microstructure of the Bi₂O₃/TiO₂ oxide system, which occur during its thermal annealing at temperatures of 150, 300, 500, and 700 °C, have been studied. Annealing of the oxide system in the range of 150–300 °C degrees leads to inconsequential morphological and structural changes: the mixture of oxides is densified, in addition to anatase, a rutile phase appears in TiO₂. The crystal system of the Bi₂O₃ phase is hexagonal. After annealing at 500 °C, not only morphological changes occurred in the studied composite, but also significant transformations in the microstructure. In the film volume, oxide phases Ti₂O₃ and Bi₂O₃ began to transform into three-component compound Bi₄Ti₃O₁₂, and this process is completed at 700 degrees with the formation of single-phase Bi₄Ti₃O₁₂ nanocomposite with an orthorhombic lattice with the crystal space group Fmmm.

Regenerated silk fibroin (RSF) protein comprising both hydrophilic and hydrophobic chain segments offer great potential for interfacial interaction and stabilization of organic nanoparticles (NPs) in aqueous medium. In this work, aqueous dispersion of poly(3-hexylthiophene):phenyl-C₆₁-butyric acid methyl ester (P3HT:PCBM) NPs of 1:1 weight ratio were prepared using RSF as surfactant for the first time via the mini-emulsion method. The size, morphology, internal structure, interface and hierarchical organization of RSF-stabilized P3HT:PCBM NPs was investigated using UV–visible spectroscopy, contrast-variation small-angle neutron scattering (CV-SANS) and ultra-small-angle neutron scattering (CV-USANS). The P3HT:PCBM NPs were established to be stabilized in the matrix of RSF colloidal microparticles in water. Unlike the commonly used surfactant sodium dodecyl sulfate which produces core–shell (PCBM–P3HT) NPs, the RSF molecules generated P3HT:PCBM NPs with internal structure that resemble phase-separated solvent-cast films. The as-prepared dispersion has good film-forming ability and has been demonstrated for fabrication of composite films comprising graphene oxide.

Graphene oxide (GO) and cellulose nanocrystal (CNC) integrated nanocomposite fibrous membrane of thermoplastic polyurethane (TPU) was designed and synthesized following a solution-specific electrospinning method. GO was investigated for its potential for mechanical and antibacterial properties’ enhancement in the TPU-focused membrane design and development. Concurrently, CNC was integrated with the combination to investigate its hydrophilicity effect in the three-constituent membrane. The membranes were deposited with average fiber diameters ranging from 142.50 nm to 164.60 nm. Testing and characterization of the membranes were found to indicate the following: 1) neither the presence of GO nor CNC nor combination of CNC and GO significantly affected the tensile properties; 2) dynamic mechanical analysis (DMA) revealed that GO and CNC were able to increase the glass transition temperature of the TPU with the strongest response resulting from the use of both nanomaterials; 3) water contact angle measurements following a Sessile drop methodology indicated that the presence of GO had little effect on the initial contact angle, CNC showed a slightly more hydrophobic initial behavior, and CNC with GO displayed a more hydrophilic initial behavior; 4) antibacterial testing showed that neither presence of GO nor CNC improved the antibacterial behavior of the TPU membranes.

In recent years, using biological materials to synthesize metallic nanoparticles has emerged as an efficient and cost-effective approach. This work synthesized silver nanoparticles (AgNPs) from Caulerpa racemosa (Cr) - Polysaccharide (Ps). UV–vis spectroscopy examined the synthesised Cr-Ps-AgNPs, revealing a colour shift and a surface plasmon resonance peak at 450 nm. The Fourier transform infrared spectroscopy is used to detect functional groups within the polysaccharide and to investigate nanoparticle interactions. Scanning Electron Microscopy revealed that the biosynthesized Cr-AgNPs varied in size from 32 to 77 nm. X-ray diffraction confirmed that the Cr-Ps-AgNPs were crystalline. Also, dynamic light scattering showed that the Cr-Ps-AgNPs particles, which were biosynthesized nanoparticles, had a size distribution that was polydisperse, with an average diameter of 42.8 nm. In a dose-dependent manner, the biosynthesized Cr-Ps-AgNPs demonstrate high antioxidant activity in the DPPH, reducing power, and total antioxidant scavenging tests. The antibacterial activity of Cr-Ps-AgNPs against Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus, and Streptococcus pyogenes was assessed using an agar well diffusion test, which revealed dose-dependent activity. The cytotoxicity investigation showed a dose-dependent activity against breast cancer cells (MCF-7), with an inhibitory concentration (IC50) of 38 μg/mL. The results of this study show that synthesised Cr-Ps-AgNPs exhibit antioxidant, antibacterial, and anticancer properties.

The rare earth dope d nano-cluster can be a building block for the next-generation photo-electrical industry, so the imminent discovery of novel, suitable nano-functional material is urgent. Praseodymium element as a wonderful dopant, bestow a novel photoelectrochemical properties for nanomaterials especially for semiconductor, derived from its unfulfilled 4f electrons configuration and active electronic transitions between 4f to 4f and 4f to 5d. In view of this, the neutral and anionic clusters of PrSi_n^0/- with a medium size of n = 10–20 are comprehensively investigated by the quantum chemistry method of mPW2PLYP associated with the global searching potential energy surface techniques. The geometry evolution in medium size for PrSi_n can be attributed to three stages of replaced (n = 10–12), linked (n = 13–19), and cage (n = 20) structure. For PrSi_n^-, two evolution phases are obviously observed by linked (n = 10–19) and cage (n = 20) structure. The PES spectra of the anionic most stable cluster and several degeneracy structures are simulated to identify the ground state structure. Each cluster of AEA, charge transfer, and VDE values are all calculated. Combined with binding energy, HOMO-LUMO gap, molecular orbital analysis, and a series of optical properties estimated, including simulated UV–vis, IR, and Raman spectra, excitation behavior shows PrSi₂₀^- has not only prominent stability but also has a proper range of lighting absorption, higher electron-hole recombination, possible as a functional material for optoelectronic devices.

The aim of the present study is to prepare carbon dots (CDs) from Acacia caesia leaves and use them to synthesize Magnetite@CD (Fe₃O₄@CD) nanocomposites (NCs). The absorbance spectrum, photoluminescence, and surface functional groups were revealed in the optical and morphological properties analysis, which confirmed the successful formation of Fe₃O₄@CD NCs. Electron microscopy showed that the NCs had an almost spherical shape, with an average particle diameter of 11.02 nm. A vibrating sample magnetometer (VSM) also confirmed the superparamagnetic behavior of Fe₃O₄@CD NCs behaved in a superparamagnetic way. This study also observed effective in vitro antioxidant, anti-inflammatory, and cytotoxicity properties, all with low inhibitory concentration 50 (IC₅₀) values. However, neither Candida albicans nor Aspergillus niger showed any potential antifungal activity by both CDs and Fe₃O₄@CD NCs. The synthesized Fe₃O₄@CD NCs demonstrate significant potential for biomedical applications due to their superparamagnetic properties and low IC₅₀ values, offering new insights into the design of multifunctional nanocomposites. Tuning the physiochemical properties of nanomaterials can have broad-field scientific applications.

Surface passivation is a well-established method for modifying carbon dots (CDs), intended to improve their properties. We present a theoretical study employing density functional theory (DFT) and time-dependent-DFT (TD-DFT) to explain the photoluminescence (PL) mechanism of amine-modified carbon dots (CD-NH₂) [CDs modified with (3-Aminopropyl) triethoxy silane (APTES)] considering their local geometry at the terminal ends; the zig-zag (CD_ZZ-NH₂) and armchair (CD_AC-NH₂) structural orientations. The experimental evidence from our previous report suggests that the amine groups were tethered on the surface of CDs through a Si-O bond realized by the silane coupling reaction between the ethoxy group of APTES and the hydroxyl group of the CDs. The effect of pH in tweaking the PL of these systems is scrutinized in the present study. The influence of pH and structure on the bandgap of CD-NH₂ is demonstrated by analyzing the difference in HOMO-LUMO energies, the density of states (DoS) spectra, and electrostatic potentials (ESP).

Nanobiocatalyst is a useful technological development that brings together modern nanotechnology and biotechnology and offers benefits for enhancing the activity, stability, and performance of enzymes in bioprocessing applications. Nanosupports used in nanocatalysts have a number of advantages over conventional materials, including a robust framework, tunable morphology, increased surface area, excellent pore geometry, inherent properties, and distinctive optical properties for the supporting matrix. Nanobiocatalysts based on silica have been used in drug delivery, optical imaging, pollution control and other catalytic processes. In this review we trace the development of silica-based nano-bio catalysts as a supporting matrix, discussing their structure-property relationships and discuss molecular-level interactions between enzymes and surfaces. The influence of parameters such as pore size, morphology, and surface modifications on immobilisation efficiency and resulting activity is also examined. Additionally, a summary and significant advancements of silica -based nano biocatalysts with potential future applications in the production of biofuel and bioremediation is provided. Overall, the review identifies nano-silica biocatalysts as a promising support and suggests future directions and challenges.

In this work, electrospun reduced graphene oxide (rGO)/nickel oxide (NiO)/poly(caprolactone) (PCL) nanofibers were prepared with different concentrations of rGO was synthesized using a chemical reduction route. X-ray diffraction peaks at 21.3° and 24.5° reveal (110) and (200) planes of PCL polymer with orthorhombic unit cell parameters. Broad peaks at 26.9° and 37.3° are the plane (002) and (111) respectively for rGO and NiO, respectively in the rGO/NiO/PCL nanofiber. The defect parameter in carbon, ID/IG, for pure rGO and rGO/NiO/PCL varied from 0.87 to 0.33, indicating an increase in the sp² domain as the rGO content increased from 5 % and 15 % of rGO/NiO/PCL nanofiber. The corrosion resistance of rGO/NiO/PCL nanofiber Ecorr and Icorr increases with increasing rGO content. In corrosion, analysis reveals the minimum values of Ecorr and Icorr are 0.04 V and 2.6 μA, respectively. The specific capacitance estimated from cyclic voltammetry, CV and Galvanic charging and discharging, GCD analysis is 381.9 Fg⁻¹ at a scan rate of 5mVs⁻¹ and 524 Fg⁻¹ respectively. The maximum energy density, E and power density, P are 72.7 W h kg⁻¹ of 499.9 k W kg⁻¹ for 15 wt% rGO/NiO/PCL nanofiber. Moreover, rGO/NiO/PCL nanocomposite exhibited good cycle stability of 65.5 % after 1000 charge–discharge cycles. NiO/rGO/PCL nanocomposite are one of the best candidates for supercapacitor application