Next Nanotechnology最新文献

Flexible nanocomposite materials were prepared by introducing Zinc Oxide (ZnO) and Carbon Black (CB) as nano-fillers separately into vulcanized natural rubber (NR). The impact of curing agents and filler integration on the structure and electrical characteristics of NR was thoroughly examined. Electrical properties such as dielectric constant, dielectric loss, and ac conductivity were assessed. Pure NR exhibited higher dielectric properties and ac conductivity compared to NR cured with pentane-1,5-deylidenediamine (PDD), which gradually decreased up to a certain threshold due to the immobilization of non-rubber constituents. Dielectric Constant of pure NR decreases from 148.81 to 6.87 upon the addition of 2 ml crosslinking agent into NR. Furthermore, NR composites filled with CB demonstrated lower dielectric properties compared to those filled with ZnO, likely attributed to the polar nature of ZnO. Dielectric Constant of cured NR was increased and exhibited 20.7 for the NR composite with 0.06 % ZnO. The surface roughness of the resulting nanocomposites was analyzed using optical profilometry, and its correlation with dielectric and ac conductivity was investigated.

This review explores the integration of graphitic carbon nitride (g-C₃N₄) with model drugs and diverse formulations to obtain nanocomposites with potential for cancer therapy. Beyond the synthesis, the study also deals with cancer-affected organs, elucidates mechanisms of drug action and categorizes g-C₃N₄-based anti-cancer compositions. The responsive elements contributing to cancer inhibition under the chemotherapeutic influence include reactive oxygen species (ROS), mitochondrial potential, oxidative stress, magnetic responsiveness, profound thermal and photo energy penetration, metal retention toxicity, adenosine triphosphate (ATP) blockade in cancer cells, insulating microenvironments within tumours and immune-modulating antibodies. Notably, breast, prostate, lung, ovary and stomach cancers owe their genesis exclusively to abnormal cell proliferation. Our review reveals that the integration of model drugs (MD) with metal ions (MI) on g-C₃N₄ (g-C₃N₄/MDMI) shows enhanced biological activity, compared to metal ions and model drugs alone. The paper refers to several characterization techniques to decipher intricate data patterns and facilitate explanations of in vitro analyses focused on cancer cell viability and proliferation. Upon analysis of all data, g-C₃N₄ emerges as a compelling drug carrier, particularly within the anticancer drug delivery systems. This review not only emphasizes the immense potential of g-C₃N₄ nanocomposites but also paves the way for future advancements in effective cancer treatments.

The Mg(OH)₂ and MgO nanomaterials were synthesized by precipitation followed by calcination from the industrial waste MgCl₂·6H₂O originated from the magnesiothermic reaction of solar-grade silicon (P-waste). A similar synthesis process was carried out in parallel with the commercial precursor MgCl₂·6H₂O (P-com) to compare the products obtained with precursors. For the synthesis of Mg(OH)₂ (1st step), aqueous solutions were prepared (low pH for P-waste and natural pH for P-com). NaOH was used as a precipitating agent, and different synthesis temperatures were evaluated (25, 50, 75, and 90 °C). MgO (2nd step) was obtained through calcination at 500 °C for 30 min of previously synthesized Mg(OH)_2. The P-waste and the two synthesis products (Mg(OH)₂ and MgO) were chemically, thermally, structurally, and morphologically characterized. The results showed that the P-waste is more soluble in an acidic environment, and both precursors present similar thermal behavior and structural profiles. The Mg(OH)₂ obtained in the 1st step of synthesis by both precursors presented the crystalline phases Brucite with lamellar morphology and Halite (NaCl) remained of the precursors. The powders obtained from both precursors in the 2nd step presented the same crystalline phase Periclase (MgO), but different morphologies such as fragmented lamellar for the P-com and cubic for the P-waste. However, the particle size distribution narrows, and the D50 of MgO decreases as a function of increasing the synthesis temperature employed in the 1st step for the P-com. In contrast, the D50 of MgO decreases in the P-waste as a function of low pH. Furthermore, surprisingly, it was observed that the morphology of MgO nanocubes can be obtained from residues and commercial precursors at low calcination temperature and short time (500 °C/30 min) when the Halite remaining from the purification washes is above 4.0% by weight.

The antibacterial property of silver nanofluid was investigated on Pseudomonas aeruginosa and Klebsiella pneumoniae. Silver nanoparticles were synthesized using Nigella sativa (black seeds), green tea, ginger, and garlic as reductant agents through hydrothermal and microwave methods. The physical characteristics of nanoparticles were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), Energy-dispersive X-ray spectroscopy (EDX), and visible ultraviolet spectroscopy (UV–vis). The crystal size measured from SEM analysis on average was about 60 nm and calculated from Debey-Scherer equation was around 43 nm. The nanofluid was prepared by solving the nanoparticles in deionized water. The effect of prepared nanofluid was examined on the growth of two kinds of bacteria that is Pseudomonas aeruginosa and Klebsiella pneumoniae by an antibacterial sensitivity test using the pour plate method. The nanofluids showed a considerable antibacterial effect on Pseudomonas aeruginosa and a moderate effect on Klebsiella pneumoniae on agar plates.

The energy crisis and complex environmental issues stemming from fossil fuel consumption have propelled the development and utilization of renewable energy sources, with electrochemical water splitting (EWS) being an effective way and ideal method for producing clean and renewable energy (hydrogen). Up to now, the majority of EWS-related reactions have been studied mainly under acidic and alkaline conditions, which have achieved relatively excellent catalytic activities and efficiencies, albeit with certain safety risks, accompanied by corrosion, contamination, and the generation of waste liquids, in addition to the demand for acid- and alkali-resistant electrocatalytic materials as well as costly anion/cation-exchange membranes. To overcome these shortcomings, the development of advanced catalysts for neutral EWS becomes an attractive and more sustainable option. Unfortunately, there are relatively few theoretical discussions and practical applications of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) as well as other anodic oxidation reactions under neutral conditions. Single/dual-atom electrocatalysts (S/DACs), characterized by maximum metal utilization efficiency, homogeneous active sites, and remarkable synergistic effect, exhibit great potential for EWS-related reactions under neutral conditions. Therefore, we provide a brief mechanistic discussion of neutral HER/OER, focusing on the synthesis, modulation strategies, characterization techniques and current representative applications in EWS-related reactions under neutral conditions, as well as the challenges and prospects of S/DACs. This review may provide some insights to facilitate the practical application of efficient hydrogen production under neutral conditions.

This study investigates integrating pixelated colloidal quantum dot (QD) layers into LCDs to enhance color conversion and pixel-level enrichment for future display technologies. We developed miniature prototypes with pixel-sized QD color-converter layers seamlessly integrated into the backlight unit (BLU). The prototypes, featuring red- and green-emitting QD pixels with a single blue LED on glass substrates, underwent rigorous environmental tests such as Thermal Shock Test (TST), Thermal Cycle Test (TCT), High Temperature High Humidity Test (HHT), and Low Temperature Test (LTT). The assessment covered the uniformity of light, spectral radiance, and CIE color coordinates, revealing insights into the performance of the QD layers through the analysis of pre- and post-environmental tests. Despite a decrease in luminance, the QD layers exhibited resilience against rapid temperature variations, enduring thermal shock, and thermal cycle tests without cracking. However, high-temperature and high-humidity conditions revealed susceptibility. Low-temperature stress tests demonstrated stable color gamut coordinates with no discernible shifts. This research fills a notable gap in the existing literature by conducting comprehensive environmental tests on pixel-sized QD utilization in display technologies, providing valuable insights to enhance the stability, durability, and reliability of QD displays.

The need for alternative treatment of infections caused by vancomycin-resistant Enterococci (VRE) is of global concern. This study used Azanza garckeana (AG) seeds to synthesize silver nanoparticles (AgNPs) with anti-VRE activity. The nanoparticles were characterized using UV-Vis, FTIR, SEM, and EDXRF. Antimicrobial activities, MIC, and MBC were evaluated by agar well and microtiter dilution, respectively. UV-spectroscopy confirmed the presence of peaks at 435 nm for spherical AgNPs. FTIR spectrum showed sharp peaks at 3441, 2936, 2859, 1640, and 1385 cm⁻¹, indicating the presence of hydroxyl, methyl, methylene, alkenyl, and alkyl groups in the AgNPs. SEM and EDXRF results revealed particles with clustered crystalline patterns and silver as the highest element present, with nickel also present in very minute amounts. The AgNPs exhibited inhibitory activity against the VRE species at both 50 and 100 µg/ml. Also, MIC values varied between 12.5 µg/ml and 25 µg/ml, while MBC values were 50 µg/ml and 25 µg/ml respectively. Conclusively, A. garckeana AgNPs demonstrated potent antimicrobial activity, suggesting their antimicrobial properties could be utilized in a variety of biomedical applications.

Perovskite solar cells (PSC) have emerged as highly efficient photovoltaic devices, boasting remarkable power conversion efficiencies (PCE) exceeding 25.5%. However, the incorporation of perovskite films raises environmental concerns due to associated toxicity, and PSC deteriorates over time due to material breakdown accelerated by heat, moisture, and undesired chemical reactions at interfaces. For example, employing titanium dioxide TiO₂ as the electron transport layer (ETL) and the organic semiconductor Spiro-OMeTAD as the hole transport layer (HTL) can lead to instability in the device. The broad bandgap of TiO₂ leads to charge carrier recombination in ETL, undermining device performance, along with the high cost and complex synthesis of Spiro-OMeTAD. Researchers have investigated several methods to tackle these challenges, including altering the interfacial structure and employing adaptable materials between the charge-gathering electrode and perovskite active layers. Due to their extensive bandgap and notable electron mobility, perovskite oxides are highly attractive; however, these materials encounter difficulties such as clustering, which can cause short circuits and leakage current. They also suffer from inefficient charge separation, surface hydrophilicity, and inadequate absorption of visible light. Furthermore, the addition of graphene particles to both compact and mesoporous TiO₂ layers, which act as electron-selective layers, aims to lower series resistance and boost electron extraction efficiency, achieving a peak PCE of 26.3%. These materials have garnered attention for their outstanding optoelectronic properties, superior stability, and non-toxic characteristics. This review extensively delves into the integration of graphene-based materials as interfacial layers and how that will affect the performance of PSC in terms of stability and efficiency.

Solar-driven steam generation technology is an environmentally friendly, cost-effective means of sewage treatment and seawater desalination. A significant challenge in the development of this technology is improving the evaporation performance of evaporation devices. Herein, we report an innovative three-dimensional (3D) solar evaporator constructed with MXene-TiO_X nanocomposite as the photothermal layer and polyvinyl alcohol hydrogel as the water-transport medium. An inverted cone-concave structure of 30° on the photothermal layer can absorb more sunlight through diffuse light reflection. The 3D solar evaporator demonstrates a notable evaporation rate of 2.09 kg m⁻² h⁻¹ , surpassing the efficacy of alternative evaporative systems. In the seawater desalination experiment, the condensed water had salinity levels that were considerably lower than the established threshold for drinking water. The ion rejection ratios for the four primary ions demonstrate a high level of efficacy, with values approaching 99.91%. In addition, the 3D solar evaporator exhibits robust performance in the context of wastewater treatment. This study provides significant contributions to the understanding of the efficiency of solar evaporators based on structural design principles, offering approaches to mitigate the challenges posed by limited freshwater availability.

The present study focuses on the hydrothermal synthesis of nickel sulfide (NiS) stabilized on carbon nanospheres (CNSs) with varying concentrations of CNSs. The samples were annealed to study the effect on their structural, chemical, and optical properties. Various characterizations were performed to confirm the presence of NiS nanocomposites, to study the annealing effects, and to examine how the increased amount of carbon nanospheres affects the sample properties. X-ray diffraction (XRD) patterns revealed the formation of multiple-phase C/NiS₂/NiSO₄·6(H₂O) nanocomposites, which were observed to be forming CNSs/NiS nanocomposites after annealing, indicating the removal of sulfate impurity. Significant variations in the bandgap and absorption spectra were observed due to the varying concentration of CNSs from 0.3 g to 0.7 g. Morphological study through field emission scanning electron microscope (FESEM) showed the formation of nanosheets of NiS₂/NiSO₄·6(H₂O) over carbon nanospheres, which was reduced to NiS after annealing. Transmission electron microscope (TEM) images of annealed samples showed the formation of CNSs/NiS nanocomposites. Electrochemical studies conducted through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) showed diffusion-controlled behavior in all samples, rendering samples ideal for solar cell applications with the value of Warburg impedance 116.4 Ohm(s)^1/2 for CNS1. Overall, the characterization results provide valuable insights into the properties and behavior of the synthesized nanocomposites.