Nano-Structures & Nano-Objects最新文献

This article proposes a mathematical investigation of unsteady flow and heat transfer in the presence of Joule Heating over a radially stretching sheet using a nanofluid of Cu-Ethylene glycol. With an extensive numerical study, we reveal the novel interaction between the shape factors of nanoparticles and surface deformations brought about by stretching. As opposed to earlier studies that have mostly concentrated on traditional nanoparticle forms, our investigation methodically looks at the unique behaviors of Cu-EG nanoparticles on stretching surfaces. The research findings offer great potential for numerous practical applications, in addition to providing insight into basic concepts related to fluid dynamics and heat transfer. The solution to this issue is significant for enhancing thermal management in manufacturing environments, such as cooling systems used in aerospace and electronics. Therefore, our work establishes a foundation for novel methods of creating materials with customized qualities, opening the door for the creation of next-generation technologies that are more sustainable and functional. A numerical solution of the highly non-linear ordinary differential equation is attained with suitable boundary conditions by applying BVP4C in MATLAB. Impact of pertinent parameters on Cu-Ethylene glycol nanofluid Joule Heating concentration, as well as Eckert, Prandtl, and Biot-number on flow and heat transport, are studied. Important results show that the Joule Heating effect raises the total heat transfer rate by roughly 15 %, and the addition of Cu nanoparticles improves thermal conductivity by around 22 %. The findings show that the combined influences of Joule Heating and nanoparticle concentration greatly increase the heat transfer efficiency, offering important new information for the optimization of cooling systems in a range of industrial applications. Finding of the current study is that the shape factor of platelets effectively transfers heat and flow, with sphere forms convey the least amount of heat.

The rGO/ZnCo₂O₄ nanocomposite (NCs) was synthesized using a hydrothermal method. The crystallite size, morphology, and optical properties of rGO, ZnCo₂O₄, and the rGO/ZnCo₂O₄ nanocomposite were extensively characterized using TG/DTA, FT-IR, UV-DRS, XRD, SEM with EDAX, and TEM techniques. The synthesized rGO/ZnCo₂O₄ NCs were crystalline with a cubic spinel structure and an average crystallite size of 19 nm, as confirmed by XRD. The optical bandgaps of pure ZnCo₂O₄ and the rGO/ZnCo₂O₄ nanocomposite were estimated to be 2.3 eV and 1.8 eV, respectively. The crystal violet (CV) dye was efficiently removed from an aqueous solution by photocatalytic degradation under visible light and sunlight irradiation in the presence of pure ZnCo₂O₄ and the rGO/ZnCo₂O₄ nanocomposite. The degradation results revealed that nearly 99.9 % of dye degradation was achieved with the rGO/ZnCo₂O₄ nanocomposite compared to pure ZnCo₂O₄ nanoparticles in 60 minutes. Hence, the rGO/ZnCo₂O₄ nanocomposite can be considered a promising and efficient photocatalyst for the degradation of crystal violet dye. The key highlight of this work is the low-cost, disruptive engineering strategy for synthesizing nanocatalysts for multifaceted applications.

This article highlights the optical, chemical, and biological properties of fluorescent curcumin-mediated zinc oxide (ZnO) nanoparticles (NPs) that were synthesized using a wet chemical precipitation technique and explores their therapeutic properties. Both curcumin and ZnO NPs exhibit exceptional antioxidant and antidiabetic properties in in vitro studies. Synthesized curcumin-ZnO NPs (Cur-ZnO NPs) was characterized via UV, X-ray powder diffraction, photoluminescence, Raman, Fourier transform infrared, scanning electron microscopy, antibacterial, antidiabetic, anticancer, and antioxidant studies. The optical photoluminescence of Cur-ZnO NPs was excited at 450 nm, corresponding to its peak emission. The synthesized NPs demonstrated high antibacterial potential when applied to two Gram-negative (E. coli and P. aeruginosa) and Gram-positive (S. pyogenes and S. aureus) bacteria. These NPs showed significant efficacy against oxidative stress and potential ability for managing diabetes mellitus by reducing the levels of α-amylase and α-glucosidase in the body. Furthermore, the Cur-ZnO NPs exhibited strong cytotoxic effects on a cancer cell line (MCF-7), causing ∼78 % of cell death. Cur-ZnO NPs hold out the prospect for more effective and less toxic therapies to combat cancer.

Gadolinium garnet ferrite (GdIG) and terbium garnet ferrite (TrIG), known for their favourable magnetic and dielectric characteristics, were combined with doped zinc spinel ferrite (GdIG)x-(TrIG)y/Mn_0.2Co_0.3Zn_0.5Fe₂O₄(1-x-y) (at x=1 y=0, x=0 y=1, x=y=0.5, x=y=0.25, x=y=0) to achieve improved permittivity, permeability and magnetic properties with reduced magneto-dielectric losses. Our study details the synthesis process and the resulting enhancements in structural, magnetic, and dielectric properties of the prepared samples. Analysis of the X-ray diffraction (XRD) patterns confirmed the presence of a crystalline structure characterized by both cubic spinel and cubic garnet phases in the composites. The microstructures of the composites were analysed with field emission scanning electron microscopy (FESEM), revealing the variation in a grain size from 0.11 μm to 0.96 μm at x =y=0.5. A thorough link between the crystal structure and XRD spectra, transmission electron microscope (TEM), and selected area electron diffraction (SAED) patterns have all been investigated in order to enhance the characterisation of the samples. At 1KHz, the composites exhibit highest electrical resistivity values of 5.9$\times$10⁶ Ωm and 2.6$\times$10⁶ Ωm. With the incorporation of spinel ferrites in garnet ferrite composite (x=y=0.25) the highest value of dielectric constant (885.2) and low value of dielectric loss (0.07) at 100 KHz has been obtained. Permeability values, derived from permittivity data, showed an increase in real permeability values of from 1.4$\times$10¹² to 9.2$\times$10¹⁷ for x=y=0.5 to x=y=0.25 composite. Vibrating sample magnetometer (VSM) further confirm that the composite x=y=0.25 has highest magnetic saturation (148.8 emu/g), coercivity (502 Oe) and microwave operating frequency (33.6 GHz). The observed high dielectric constant, low loss values, switching field distribution and good magnetic properties suggest the potential suitability of these samples for various electronic devices like: high frequency devices, antennas, switching devices and magnetic recording devices.

The development of eco-friendly and sustainable nano textile materials has become a crucial response to the environmental problems facing the textile industry as well as the need for increased functionality. This review delves into the history of nano textiles, following advancements from their inception to present-day uses and potential future directions. In the past, the textile industry has struggled with environmental problems such as pollution and overuse of resources. With the use of nanotechnology, textiles can now have better qualities like increased stain resistance, durability, and antibacterial performance. There is currently a major shift toward the integration of eco-friendly nanomaterials, such as biodegradable and bio-based nanoparticles, which support more sustainable production practices. These developments not only address environmental issues but also enhance textile performance, offering attributes like water resistance, UV protection, and self-cleaning capabilities. Future directions are expected to center on refining nanomaterial synthesis, scaling production, and ensuring comprehensive lifecycle sustainability. Emerging trends, such as smart functionalities and circular economy approaches, are anticipated to further revolutionize the industry. This review summarizes previous accomplishments, assesses recent innovations, and identifies future research opportunities to advance the field of green nano textiles.

The design and fabrication of smart and low-cost nanocomposites (NCs) is still an area of challenge in wastewater treatment. In this context, firstly individual graphene oxide (GO) and cerium oxide (CeO₂) nanoparticles (NPs) were synthesized by precipitation method. This was followed by synthesis of GO-CeO₂-NCs by mixing GO and CeO₂-NPs in natural surfactant which was characterized by UV–visible absorption spectroscopy. The morphology of the synthesized GO-CeO₂-NCs was established by scanning electron microscopy (SEM) studies while high resolution transmission electron microscopy (HRTEM) analysis revealed shape and particle size of the synthesized NCs. Fourier transform infrared spectroscopy (FTIR) was used to confirm the presence of different functional groups in the synthesized GO-CeO₂-NCs and thermal stability was determined by thermal gravimetric analysis (TGA). The synthesized GO-CeO₂-NCs was used as catalyst in heterogeneous Fenton process for the degradation of methyl violet (MV) dye. The effects of various experimental parameters, i.e., pH, H₂O₂, GO-CeO₂ NCs for MV degradation were investigated to have optimum condition. The optimum conditions for effective degradation with 98 % was achieved just within 100 minutes, at pH=8, [H₂O₂] 80×10⁻⁴ M, and [GO-CeO₂] 18 mg/L for 3×10⁻³ M degradation. The experimental observations have led up to propose a most plausible mechanism for GO-CeO₂-NCs enhanced Fenton’s degradation of MV. GO-CeO₂ nanocomposites with H₂O₂ shows amazing removal capacities in the elimination of MV. In summary, synthesized GO-CeO₂ nanocomposites demonstrate remarkable efficiency in present work, and offering a promising solution for the effective degradation of methyl violet dye in wastewater treatment.

The optical and thermoplasmonic properties of bimetallic nanoparticles (NPs) offer a wide range of possibilities for designing functional materials and innovative nanotechnological devices. Their exploration is generating increasing interest in experimental and theoretical scientific research. The combination of noble metals such as gold (Au) and silver (Ag) within the same nanostructure, in the form of an alloy or core/shell arrangement, presents several advantages and potential applications. In this paper, the finite element method (FEM) is used to study the optical response and nanoscale heat generation capability of bimetallic core/shell nanospheres composed of a mixed alloy ${(\mathrm{Au}}_x{\mathrm{Ag}}_{1-x})$-core and an Au-shell. First, we studied the surface plasmon resonance (SPR) properties by generating absorption spectra. Our results show that the position and amplitude of the SPR peak of these nanospheres are strongly influenced by the fractions of Au and Ag metals composing the core, as well as by the Au-shell thickness. In particular, the SPR-peak position can be adjusted between $535\mathrm{nm}$ and $1085\mathrm{nm}$ depending on the composition and structure of these NPs. Secondly, we studied the ability of these NPs to convert absorbed light into heat when exposed to either a continuous wave (cw) laser or a femtosecond pulsed (fs-pulsed) laser. The results demonstrate the ability to control the temperature generated by these NPs based on the core composition, Au-shell thickness, illumination intensity, and the type of illumination (cw or fs-pulsed). In particular, under fs-pulsed illumination, the internal temperature of the NPs is significantly higher than under cw illumination. These findings are crucial for the use of these alloy-core and Au-shell nanoparticles in various thermoplasmonic applications.

In this communication, effect of Gd doping for CoFe_2–xGd_xO₄ (CFGO) nanoparticles has been investigated for structural, magnetic and electrical properties. X–ray diffraction (XRD) patterns reveal the presence of matrix like CFGO phase fraction with coexisting GdFeO₃ (GFO) smaller crystallites and α–Fe₂O₃ (FO) phase fraction. Variation in crystallite size (D) for all three phases has been explored from the analysis on XRD patterns. Magnetic nature has been understood on the basis of lattice disorder, magnetic linkages between different ions of CFGO lattices that conduces magnetic characteristic of three different phases coexist within the CFGO nanoparticle lattices. Influence of frequency, temperature and Gd doping level on different electrical behaviors has been understood on the bases of various relaxation processes, charge conduction mechanism, correlated barrier hopping (CBH) mechanism, maximum barrier height, activation energy and structure–property correlations.

Water is the basic entity required for the survival of any life form on earth. However, in the present scenario, due to its contamination with various types of contaminants, there is a global crisis of water. One of the major organic pollutants described to be present in most industrial-modeled water is 4-nitrophenol. Due to its persistence and high potential for bioaccumulation, it is considered a high-priority environmental and health concern. Numerous nanomaterials are considered to have huge potential in the treatment of contaminated water due to their unique high surface area as well as some beneficial properties that support work even in low concentrations. In the last few years, much attention has been paid by scientists to different applications of nanocomposites for water purification. This review represents a comprehensive approach to how to enhance nanocomposite-mediated adsorption for effective 4-NP removal from modeled water. It involves high adsorption capacity, with adsorbents calcium and aluminum layered double hydroxide-loaded magnetic nanocomposite and magnetite nanoparticles, with capacities as high as 598 mg g-1 and 636 mg g-1, respectively. Such advanced materials may improve the hydrophilicity and mechanical properties of the material. The processes could be endothermic and exothermic in nature. pH also plays a role in performance, where, in most studies, conditions above 6 corroborate the removal of 4-NP. Textural properties and functional groups present on the surface of the adsorbent also determine whether the process is physical or chemical. Further studies should be focused on large-scale decontamination of the contaminant, entrenching the use of low-cost and environmentally friendly adsorbents that are more environmentally acceptable in real applications. This would not enable researchers to follow up with new strategies for the remediation of water that is contaminated with 4-NP on the basis of making a model for engineering nanocomposites for the remediation of contaminants.