Nanoscale Research Letters最新文献

The technology of RGBY micro resonant cavity light emitting diodes (micro-RCLEDs) based on quantum dots (QDs) is considered one of the most promising approaches for full-color displays. In this work, we propose a novel structure combining a high color conversion efficiency (CCE) QD photoresist (QDPR) color conversion layer (CCL) with blue light micro RCLEDs, incorporating an ultra-thin yellow color filter. The additional TiO₂ particles inside the QDPR CCL can scatter light and disperse QDs, thus reducing the self-aggregation phenomenon and enhancing the eventual illumination uniformity. Considering the blue light leakage, the influences of adding different color filters are investigated by illumination design software. Finally, the introduction of low-temperature atomic layer deposition (ALD) passivation protection technology at the top of the CCL can enhance the device's reliability. The introduction of RGBY four-color subpixels provides a viable path for developing low-energy consumption, high uniformity, and efficient color conversion displays.

Carbon nanotube (CNT) has fostered research as a promising nanomaterial for a variety of applications due to its exceptional mechanical, optical, and electrical characteristics. The present article proposes a novel and comprehensive micromechanical framework to assess the viscoelastic properties of a multiscale CNT-reinforced two-dimensional (2D) woven hybrid composite. It also focuses on demonstrating the utilisation of the proposed micromechanics in the dynamic analysis of shell structure. First, the detailed constructional attributes of the proposed trans-scale composite material system are described in detail. Then, according to the nature of the constructional feature, mathematical modelling of each constituent phase or building block’s material properties is established to evaluate the homogenised viscoelastic properties of the proposed composite material system. To highlight the novelty of this study, the viscoelastic characteristics of the modified matrix are developed using the micromechanics method of Mori–Tanaka (MT) in combination with the weak viscoelastic interphase (WI) theory. In the entire micromechanical framework, the CNTs are considered to be randomly oriented. The strength of the material (SOM) approach is used to establish mathematical frameworks for the viscoelastic characteristics of yarns, whereas the unit cell method (UCM) is used to determine the viscoelastic properties of the representative unit cell (RUC). Different numerical results have been obtained by varying the CNT composition, interface conditions, agglomeration, carbon fibre volume percentage, excitation frequency, and temperature. The influences of geometrical parameters like yarn thickness, width, and the gap length to yarn width ratio on the viscoelasticity of such composite material systems are also explored. The current study also addresses the issue of resultant anisotropic viscoelastic properties due to the use of dissimilar yarn thickness. The results of this micromechanical analysis provide valuable insights into the viscoelastic properties of the proposed composite material system and suggest its potential applications in vibration damping. To demonstrate the application of developed novel micromechanics in vibration analysis, as one of the main contributions, comprehensive numerical experiments are conducted on a shell panel. The results show a significant reduction in vibration amplitudes compared to traditional composite materials in the frequency response and transient response analyses. To focus on the aspect of micromechanical behaviour on dynamic response and for the purpose of brevity, only linear strain displacement relationships are considered for dynamic analysis. These insights could inform future research and development in the field of composite materials.

This work studied the thermal stability, electrical, and thermoelectrical properties of copper(I) selenide, Cu₂Se synthesized by high-energy milling in a planetary ball mill. The phase composition was investigated by X-ray powder diffraction analysis and scanning electron microscopy. The conversion of the precursors during mechanochemical synthesis and the stability of the product was monitored by thermal analysis. The dependence of electrical properties on the product porosity was observed. For the densification of Cu₂Se, the method of spark plasma sintering was applied to prepare suitable samples for thermoelectric characterization. High-temperature thermoelectric properties of synthetic Cu₂Se were compared to its natural analogue-mineral berzelianite in terms of its potential application in energy conversion. Based on the results a relatively high figure-of-merit, ZT parameter (~ 1.15, T = 770 K) was obtained for undoped Cu₂Se, prepared by rapid mechanochemical reaction (5 min). Cyclic voltammetry measurements of Na/NaClO₄/Cu₂Se cell implied that mechanochemically synthesized Cu₂Se could be used as a promising intercalation electrode for sodium-ion batteries.

Extracellular vesicles (EVs) have mostly been investigated as carriers of biological therapeutics such as proteins and RNA. Nevertheless, small-molecule drugs of natural or synthetic origin have also been loaded into EVs, resulting in an improvement of their therapeutic properties. A few methods have been employed for EV cargo loading, but poor yield and drastic modifications of vesicles remain unsolved challenges. We tested a different strategy based on temporary pH alteration through incubation of EVs with alkaline sodium carbonate, which resulted in conspicuous exogenous molecule incorporation. In-depth characterization showed that vesicle size, morphology, composition, and uptake were not affected. Our method was more efficient than gold-standard electroporation, particularly for a potential therapeutic toxin: the plant Ribosome Inactivating Protein saporin. The encapsulated saporin resulted protected from degradation, and was efficiently conveyed to receiving cancer cells and triggered cell death. EV-delivered saporin was more cytotoxic compared to the free toxin. This approach allows both the structural preservation of vesicle properties and the transfer of protected cargo in the context of drug delivery.

Graphic Abstract

Candida species are escalating resistance to conventional antifungal treatments, intensifying their virulence, and obstructing the effectiveness of antifungal medications. Addressing this challenge is essential for effectively managing Candida infections. The overarching objective is to advance the development of more efficient and precise therapies tailored to counter Candida infections. This study focuses on developing antifungal combined drugs using curcumin-enhanced silver-functionalized graphene nanocomposites (Cur-AgrGO) to effectively target key virulence factors of C. albicans, C. tropicalis, and C. glabrata (Candida spp.). The green reduction of graphene oxide (GO) using bioentities and active molecules makes this approach cost-effective and environmentally friendly. The nanocomposites were characterized using various techniques. Combining Cur-AgrGO with photodynamic therapy (PDT) demonstrated effective antifungal and antibiofilm activity with delayed growth and metabolism. The nanocomposites effectively suppressed hyphal transition and reduced key virulence factors, including proteinases, phospholipases, ergosterol levels, and cell membrane integrity. The findings suggest that Cur-AgrGO + PDT has potential as a treatment option for Candida infections. This innovative approach holds promise for treating Candida infections.

Graphical abstract

Spin–orbit couplings (SOCs), originating from the relativistic corrections in the Dirac equation, offer nonlinearity in the classical limit and are capable of driving chaotic dynamics. In a nanoscale quantum dot confined by a two-dimensional parabolic potential with SOCs, various quantum scar states emerge quasi-periodically in the eigenstates of the system, when the ratio of confinement energies in the two directions is nearly commensurable. The scars, displaying both quantum interference and classical trajectory features on the electron density, due to relativistic effects, serve as a bridge between the classical and quantum behaviors of the system. When the strengths of Rashba and Dresselhaus SOCs are identical, the chaos in the classical limit is eliminated as the classical Hamilton’s equations become linear, leading to the disappearance of all quantum scar states. Importantly, the quantum scars induced by SOCs are robust against small perturbations of system parameters. With precise control achievable through external gating, the quantum scar induced by Rashba SOC is fully controllable and detectable.

Titanium dioxide nanoparticles (TiO₂-NPs) are a promising anode material for Lithium-ion batteries (LIBs) due to their good rate capability, low cost, non-toxicity, excellent structural stability, extended cycle life, and low volumetric change (∼4%) during the Li⁺ insertion/de-insertion process. In the present paper, anatase TiO₂-NPs with an average particle size of ~ 12 nm were synthesized via a green synthesis route using Beta vulgaris (Beetroot) extract, and the synthesized TiO₂-NPs were evaluated as anode material in LIBs. Furthermore, we employed an aqueous binder (1:1 mixture of carboxy methyl cellulose and styrene butadiene) for electrode processing, making the process cost-effective and environmentally friendly. The results revealed that the Li/TiO₂ half-cells delivered an initial discharge capacity of 209.7 mAh g⁻¹ and exhibited superior rate capability (149 mAh g⁻¹ at 20 C) and cycling performances. Even at the 5C rate, the material retained a capacity of 82.2% at the end of 100 cycles. The synthesis route of TiO₂-NPs and the aqueous binder-based electrode processing described in the present work are facile, green, and low-cost and are thus practically beneficial for producing low-cost and high-performance anodes for advanced LIBs.

The green synthesis of metallic nanoparticles is attributable towards diverse applications in various fields, recently. In this research, we report simple and eco-friendly synthesis of chromium oxide (Cr₂O₃) nanoparticles using the fruit extract of Phyllanthus emblica as a reducing and capping agent. The absorbance peaks at 350 nm and 450 nm validated the nanoparticle formation in UV–visible spectrum. FTIR spectrum revealed the nature of functional groups. The crystalline properties of nanoparticles were ascertained by XRD analysis. EDX spectrum corroborated the elemental composition of nanoparticles in which chromium and oxygen constituted 68% of total weight. SEM images demonstrated agglomeration of nanoparticles resulting in the formation of large irregularly shaped flakes. Cr₂O₃ nanoparticles demonstrated excellent antimicrobial properties against 11 bacterial isolates and 1 fungal isolate. The largest inhibition zone (53 mm) was measured against A. baumannii while the smallest inhibition zone (26 mm) was recorded against S. aureus. Minimum inhibitory concentration (MIC) values were < 1 µg/ml for all microbes. However, the synthesized nanoparticles did not reveal synergism with any of the selected antibiotics (FICI values > 1). Nanoparticles possessed potent anti-biofilm powers with maximum (77%) inhibition of E. coli biofilms and minimum (45%) inhibition of S. enterica biofilms. Photocatalytic activity of Cr₂O₃ nanoparticles was evaluated to determine their efficacy in environmental bioremediation. Outcomes demonstrated degradation of methyl red (84%) but not of methylene blue dye. Furthermore, the Cr₂O₃ nanoparticles displayed considerable antioxidant (43%) as well as anti-inflammatory (44%) potentials. Hence, the present study accounts for the versatile applications of P. emblica-mediated Cr₂O₃ nanoparticles which could be pursued for future biomedical and environmental applications.

Graphical Abstract

Titanium dioxide (TiO₂) nanoparticles have gained significant attention due to their wide-ranging applications. This research explores an approach to functionalize Niobium Nitrogen Titanium Dioxide nanoparticles (Nb-N-TiO₂ NPs) with Mentha arvensis ethanolic leaf extracts. This functionalization allows doped NPs to interact with the bioactive compounds in extracts, synergizing their antioxidant activity. While previous studies have investigated the antioxidant properties of TiO₂ NPs synthesized using ethanolic extracts of Mentha arvensis, limited research has focused on evaluating the antioxidant potential of doped nanoparticles functionalized with plant extracts. The characterization analyses are employed by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Ultraviolet–visible (UV–Vis) spectroscopy to evaluate these functionalized doped nanoparticles thoroughly. Subsequently, the antioxidant capabilities through the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) assays have been assessed. Within functionalized Nb-N-TiO₂, the FTIR has a distinctive peak at 2350, 2010, 1312, 1212, and 1010 cm⁻¹ with decreased transmittance associated with vibrations linked to the Nb-N bond. SEM revealed a triangular aggregation pattern, 500 nm to 2 µm of functionalized Nb-N-TiO₂ NPs. Functionalized doped Nb-N-TiO₂ NPs at 500 µg mL⁻¹ exhibited particularly robust antioxidant activity, achieving an impressive 79% efficacy at DPPH assessment; meanwhile, ferric reduction efficiency of functionalized doped Nb-N-TiO₂ showed maximum 72.16%. In conclusion, doped Nb-N-TiO₂ NPs exhibit significantly enhanced antioxidant properties when functionalized with Mentha arvensis ethanolic extract compared to pure Nb-N-TiO₂ manifested that doped Nb-N-TiO₂ have broad promising endeavors for various biomedicine applications.

Effective treatment of oily wastewater, which is toxic and harmful and causes serious environmental pollution and health risks, has become an important research field. Membrane separation technology has emerged as a key area of investigation in oil–water separation research due to its high separation efficiency, low costs, and user-friendly operation. This review aims to report on the advances in the research of various types of separation membranes around emulsion permeance, separation efficiency, antifouling efficiency, and stimulus responsiveness. Meanwhile, the challenges encountered in oil–water separation membranes are examined, and potential research avenues are identified.