Search Results (427)

Nanotechnology holds great promise for alleviating drought stress in crops. This study elucidates and compares the distinct physiological mechanisms by which two nanomaterials, nano-cerium oxide (CeO₂) and nano-titanium dioxide (TiO₂), function as seed-priming agents to enhance drought tolerance in barley. A comprehensive analysis encompassing germination performance, hormonal dynamics, starch metabolism, osmotic adjustment, photosynthetic pigments, and the antioxidant system revealed that each nanomaterial operates through a unique pathway. Specifically, priming with 150 mg·L⁻¹ nano-CeO₂ (CP-150) primarily promoted root development and stress resilience. This effect was achieved by persistently reducing abscisic acid (ABA) levels, elevating gibberellin (GA₃), enhancing amylase activity to mobilize seed reserves, and increasing soluble protein accumulation in roots. In contrast, priming with 500 mg·L⁻¹ nano-TiO₂ (TP-500) was more effective in enhancing shoot physiology and adaptive capacity by rapidly inducing auxin (IAA), robustly stimulating the antioxidant enzyme system, and increasing photosynthetic pigment content. The temporally and spatially complementary actions of these nanomaterials, with nano-CeO₂ fostering root-based resilience and nano-TiO₂ boosting shoot-level functions, synergistically support seed germination and seedling establishment under drought conditions. This study provides a mechanistic foundation for designing targeted nano-priming strategies to improve crop drought resistance. Full article

This study investigated the combined effects of climate change-related salinity extremes and nanoparticle pollution on the seagrass Posidonia oceanica and the macroalga Caulerpa prolifera. Both species were exposed, individually and in co-occurrence, to different salinity regimes (34; 38 and 42 g kg⁻¹) and to the emerging contaminant nano-TiO₂ (0.7 mg L⁻¹, environmentally relevant concentration, and 5.0 mg L⁻¹, high-stress exposure). Biochemical and physiological responses were assessed at baseline (T0) and after 3, 6, and 12 days of exposure, followed by a 12-day recovery phase to evaluate post-stress resilience. This multifactorial design enabled the evaluation of interactive and cumulative effects of salinity shifts associated with climate change and nanoparticle contamination. Results showed that P. oceanica was particularly sensitive to nano-TiO₂ at a concentration of42 g kg⁻¹. Reduced photosynthetic performance was associated with enhanced oxidative stress and limited recovery capacity, suggesting potential long-term impacts on meadow persistence and ecosystem functioning. In contrast, C. prolifera exhibited higher tolerance and recovery efficiency, potentially gaining a competitive advantage under climate-induced environmental variability and increasing the risk of seagrass decline and community shifts in coastal ecosystems. These biochemical markers of early stress do not necessarily reflect direct population effects, particularly in long-lived foundation species such as Posidonia oceanica. Full article

Titanium dioxide (TiO₂) nano- and submicrometric particles’ widespread use in different sectors raised concerns about human and environmental exposure. The validation of analytical methods is essential to ensure reliability in risk assessment studies. In this study, a single-particle inductively coupled plasma mass spectrometry (spICP-MS) method was validated for the detection, quantification, and dimensional characterization of TiO₂ particles in biological tissues. Tissue samples collected after exposure to TiO₂ particles underwent mild acidic digestion using a HNO₃/H₂O₂ mixture to achieve complete matrix decomposition while preserving particle integrity. The resulting digests were analyzed by ICP-MS operated in single-particle mode to quantify and size TiO₂ particles. Method validation was conducted according to ISO/IEC 17025:2017 and included linearity, repeatability, recovery, and detection limit assessments. The limit of detection for TiO₂ particles was 0.04 µg/g, and 55.7 nm was the size the detection limit. Repeatability was within 0.5–11.5% for both TiO₂ mass concentrations and particle size determination. The validated method was applied to tissues from inhalation-exposed subjects, showing TiO₂ levels of 80 ± 20 µg TiO₂/g and particle number concentrations of 5.0 × 10⁵ ± 1.2 × 10⁵ part. TiO₂/mg. Detected TiO₂ particles’ mean diameter ranged from 230 to 330 nm. The developed and validated spICP-MS method provides robust and sensitive quantification of TiO₂ particles in biological matrices, supporting its use in human biomonitoring and exposure assessment studies. Full article

In this study, magnesium-modified clinoptilolite (MZ) was successfully synthesized via precipitation and calcination to efficiently remove Pb(II) from aqueous solutions. The material was systematically characterized using BET, XRD, SEM-EDX, FT-IR, and XPS. Adsorption kinetics followed a pseudo-second-order model (R² = 0.9956), with MZ removing over 70% of Pb(II) within the first 3 h. Isotherm data were best described by the Langmuir model (R² = 0.9686), confirming monolayer chemical adsorption, with a maximum adsorption capacity (q_m) of 1656 mg/g. Notably, MZ maintained high adsorption capacity across a pH range of 3.0~5.5, and its performance was largely unaffected by the presence of high concentrations of competing ions (0.1~1.0 M NaNO₃). Mechanistic analysis revealed that the loaded MgO facilitates the chemical conversion of Pb(II) to hydroxycarbonate (Pb₃(CO₃)₂(OH)₂) via surface complexation, which constitutes the primary removal mechanism. These findings demonstrate that magnesium modification can transform natural zeolites into high-capacity, stable adsorbents, offering promising potential for the treatment of Pb(II)-contaminated water. Full article

This work presents a green chemistry route to obtain titanium dioxide TiO₂ nanoparticles with an average size of about 13.25 nm using lemongrass (Cymbopogon citratus) extract. For these assessments, TiO₂ nanoparticles were added to the coating at concentrations of 1% and 5% w/w on fiber-cement sheets. Self-cleaning evaluation was analyzed by the photodegradation of methylene blue (MB) dye at concentrations of 5, 10, and 20 mg/L applied to the coated sheet, and then exposed to simulated sunlight. The coating containing 5 wt% TiO₂ nanoparticles showed the highest photodegradation, reaching 93.3% after 4 h under simulated sunlight exposure at the lowest MB concentration (5 mg/L). Additionally, average contact angles of 80.4°, 92.03°, and 104.25° were determined for coatings containing 0%, 1%, and 5 wt% TiO₂, respectively. Moreover, the modified 5 wt% TiO₂ exhibited up to 30.9% greater hydrophobicity than the control. Antifungal efficacy against Aspergillus niger and Penicillium was evaluated using the Poisoned Food method with nanoparticles at concentrations of 1 and 3 mg/mL showing a moderate growth inhibition. In conclusion, the versatility demonstrated suggests potential applications such as a nano-additive for aqueous acrylic coatings, improving hydrophobicity, self-cleaning and antifungal properties, which could be attractive to the construction industry. Full article

Ozone micro–nano bubbles (OMNBs) are an emerging preservation technology. However, there are few reports regarding their application in controlling postharvest diseases of agricultural products. Radix astragali, as a medicinal and edible plant, is particularly vulnerable to pathogenic microorganisms during postharvest storage, which leads to diminishing the quality and commercial value. In this study, fresh R. astragali inoculated with Penicillium polonicum was treated with different concentrations (2, 3, 4, 5, 6, 8 mg/L) of OMNBs and stored at room temperature for 28 days. The results indicate that 3 mg/L OMNBs application for 8 min effectively inhibited the development of blue mold in fresh R. astragali and preserved its quality. Then, we compared the three different treatments of micro–nano bubbles (MNBs), 3 mg/L O₃, and 3 mg/L OMNBs on physiological and pathological parameters of un-inoculated fresh R. astragali during storage and analyzed the changes in the active ingredients by liquid chromatography and metabolomics. The results indicate that the 3 mg/L OMNBs treatment effectively inhibited the decline in weight loss rate, respiratory rate, firmness, browning index, and ABTS and DPPH radical-scavenging rates, as well as reduced the incidence rate and disease index of fresh R. astragali during storage. The metabolomics results suggest that the 3 mg/L OMNBs application activated the mevalonate pathway (MVA), the methylerythritol phosphate pathway (MEP), and the phenylpropanoid biosynthesis pathway to maintain the content of active ingredients such as terpenoids and flavonoids, and these findings are consistent with the results of HPLC-MS analysis. Full article

Spinel-based glass-ceramics face challenges such as a narrow crystallization window for the target phase and the difficulty in suppressing the competitive Li_xAl_xSi_1−xO₂ crystals. This study proposes a method to regulate the phase formation in ZnO-MgO-Al₂O₃-SiO₂ glass by precisely controlling the heat treatment temperature. The microstructural evolution was analyzed by DSC, XRD, Raman spectroscopy, SEM, TEM, and XPS. The results indicate that the heat treatment at a nucleation temperature of 780 °C for 2 h and a crystallization temperature of 880 °C for 2 h effectively inhibits the precipitation of the Li_xAl_xSi_1−xO₂ secondary phase, yielding a glass-ceramic with nano-sized MgAl₂O₄, ZnAl₂O₄ spinel as the primary crystalline phase. The obtained glass-ceramic exhibits excellent mechanical properties, including a Vickers hardness of 922.6 HV, a flexural strength of 384 MPa, and an elastic modulus of 113 GPa, while maintaining a high visible light transmittance of 84.3%. This work provides a clear processing window and theoretical basis for fabricating high-performance, highly transparent spinel-based glass-ceramics through tailored heat treatment. Full article

There is a growing demand for biocompatible, non-toxic nanomaterials with specific functional properties, including catalytic activity. In this study, magnetic iron oxide nanoparticles were synthesized via chemical co-precipitation in the presence of polyethylene glycol (PEG). PEG was used as a coating agent to reduce particle agglomeration. Comprehensive characterization of the synthesized nanocomposites was performed using scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX) and vibrating sample magnetometry (VSM). SEM studies confirmed the nanosized structure of the particles with an average diameter of 20–60 nm. The saturation magnetization values were 57.37 emu·g⁻¹ for nFe₃O₄-PEG6000, 11.95 emu·g⁻¹ for nFe₃O₄-PEG4000 and 3.97 emu·g⁻¹ for nCo_0.5Ni_0.5Fe₂O₄-PEG4000. In addition to their high magnetic properties, ferrofluids exhibited peroxidase-like activity, which makes them highly suitable for bioanalytical and biomedical use. The Michaelis–Menten constant (K_M) for hydrogen peroxide ranged from 1.15 to 4.98 mM. Transmission electron microscopy (TEM) proved the penetration of the nano-ferrofluids into the yeast cells of Ogataea polymorpha. The studied nano-ferrofluids were found to be non-toxic at concentrations up to 0.2 mg·mL⁻¹ for both prokaryotic and eukaryotic cells, showing no inhibitory effect on the growth of the bacterium Escherichia coli, the yeast Ogataea polymorpha, or animal and human cell lines. These results indicate that the advantages of synthetic nano-ferrofluids—including peroxidase-like activity, strong magnetic properties, cost-effective synthesis, stability, and low toxicity—make the synthesized nano-ferrofluids highly promising for future biomedical and bioanalytical applications. Full article

Nano-biochar (n-BC) is an emerging eco-friendly material with potential to improve crop performance under salt stress. This study aimed to evaluate the effects of foliar applications of bamboo-derived n-BC on the morphological and biochemical responses of lettuce plants under salt stress (40 mM NaCl). n-BC solutions (1.0, 3.0, and 5.0% w/v) were foliar-applied every five days until harvest. Salt stress markedly increased hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) by 264.54% and 14.02%, disrupted Na⁺/K⁺ homeostasis, and reduced biomass. Foliar n-BC mitigated these effects by reducing Na⁺ accumulation by 22.24–25.11% and enhancing K⁺, Ca²⁺, and Mg²⁺ uptake. The treatments also improved photosynthetic pigments and increased proline, soluble proteins, and soluble sugars. Oxidative damage was alleviated, as reflected by reductions in H₂O₂ and MDA together with enhanced ascorbate peroxidase, catalase, and superoxide dismutase activities. Total phenolics, flavonoids, and ABTS and DPPH scavenging activities also increased under n-BC application. Among all the concentrations, 3.0% (w/v) n-BC consistently produced the greatest improvements in growth, ionic balance, and antioxidant responses. These findings demonstrate that bamboo-derived n-BC is a promising foliar biostimulant for enhancing lettuce performance under saline conditions. Full article

This study systematically investigates the effect and mechanism of a TiO₂ nano-lubricant on edge cracking and surface quality during the rolling of Mg/Al composite foils. Initial friction and wear tests identified an optimal nano-lubricant concentration of 3.0 wt.%, at which the system achieved a minimum average coefficient of friction of 0.067. Subsequent rolling tests using this concentration showed that the nano-lubricant reduced rolling force by 5.39–7.54% compared to dry conditions. It also significantly suppressed the initiation and propagation of edge cracks. Furthermore, the surface roughness parameters Ra and Rz were reduced by 16.5% to 24.0%, and the height profile fluctuation range was reduced by 33% to 45%, resulting in a smoother and more uniform surface morphology. The analysis of the underlying mechanism indicates that the superior performance originates from the synergistic effects of the rolling effect, the mending effect, the polishing effect, and the protective film effect. This work establishes that the use of a 3.0 wt.% TiO₂ nano-lubricant is a viable strategy for fabricating high-quality Mg/Al composite foils with minimal defects. It thereby offers both theoretical and practical guidance for the advanced rolling of bimetallic composites. Full article

Phenol, an essential feedstock widely used in manufacturing and chemical industries, inevitably results in the discharge of phenol-laden wastewater. To enhance the phenol-degradation efficiency of Fe-based amorphous alloys, a novel atomic-scale fabrication approach for Fe-Cu galvanic couples is proposed, enabling the rapid and uniform formation of micro/nano Fe-Cu structures on the surface of Fe-based alloys with significant improvement in the catalytic activity towards phenol. Micron/nano Fe-Cu couples can be fabricated within 15 s at 45 °C. Phenol degradation experiments reveal that the pristine amorphous alloy exhibits a 40 min hatching period before the phenol removal process, and it exhibits a kinetic constant (k_obs) of 0.1596 min⁻¹ after the hatching period, under conditions of 50 °C, 0.5 g/L catalytic loading, 10 mmol/L H₂O₂, and pH = 3 towards a 50 mg/L phenol solution. With the micro/nano Fe-Cu galvanic couples, the k_obs value markedly increased to 2.23~2.36 min⁻¹ under identical conditions except for 3 mmol/L H₂O₂, corresponding to approximately a 14-fold improvement. This cost-effective and time-efficient atomic-scale fabrication strategy offers a promising platform for the development of next-generation catalytic alloys and functional materials. Full article

Addressing the significant pressure for carbon emission reduction in the cement industry, the development of novel cement materials capable of achieving “in situ carbon sequestration” has become an important research focus. This study introduces nesquehonite (MgCO₃·3H₂O, NQ) as a functional admixture into the Portland cement system, systematically investigating its effects on the cement hydration process, the evolution of hydration products, and its carbon sequestration efficiency. Through designed penetration resistance tests and hydration tests with a high water-to-solid ratio, this research utilized X-ray diffraction analysis to determine the phase composition and content of hydration products at different ages. This was combined with scanning electron microscopy to observe microstructural evolution and Nano Measure software 1.2.5 for ettringite crystal size measurement, analyzing the impact of NQ on the early hydration process of P.I cement. The results indicate that the incorporation of NQ significantly alters the early hydration of P.I cement. The Mg²⁺ and CO₃²⁻ ions released upon its dissolution interact with Ca²⁺ and OH⁻ in the pore solution, effectively promoting the early precipitation of carbon sequestration products such as calcium carbonate and minor magnesium-containing carbonates. The addition of 10% NQ hindered the crystallization of Ca(OH)₂ before 6 h but promoted its formation after 24 h. Mechanical property tests revealed that a sample with an optimal 3% NQ dosage not only increased the paste’s penetration resistance but also enhanced the compressive strength of the 1-day hardened sample by 8.37% compared to the plain sample, without a decrease and even a slight increase at 28 days. This enhancement is closely related to the microstructural strengthening effect induced by the carbonation products. This study confirms the feasibility of using NQ to steer the cement hydration pathway towards a low-carbon direction, revealing its dual functionality in regulating hydration and sequestering carbon within cement-based materials. The findings provide a new theoretical basis and technical pathway for developing high-performance, low-carbon cement. Full article

Iron deficiency limits plant growth and is usually addressed with iron fertilizers. Iron−based nanomaterials (nZVI, α−FeOOH, α−Fe₂O₃, γ−Fe₂O₃, and Fe₃O₄) show promise as novel alternatives, but the effects of sulfide nano−zero−valent iron (S−nZVI) on crops remain little studied. Thus, this study aimed to synthesize a novel iron−based nanomaterial, S−nZVI, using a one−step method, and to evaluate the effects of S−nZVI and nZVI at concentrations ranging from 5 to 100 mg L⁻¹ on the physiological and photosynthetic characteristics of Chinese cabbage (Brassica rapa L.). In the study, foliar application of iron nanoparticles increased leaf area, biomass, and photosynthesis, with 50 mg L⁻¹ the most efficient concentration (S−nZVI > nZVI). Moreover, the photosynthetic rate of the leaves increased significantly (>200%), and carbohydrate accumulation also increased significantly. Additionally, S−nZVI treatment increased leaf iron content by 5.8−fold compared to the control group, likely by enhancing the activity of antioxidant enzymes. However, the 100 mg L⁻¹ S−nZVI treatment significantly inhibited these physiological and biochemical indicators. Overall, the foliar S−nZVI (50 mg L⁻¹) enhanced Chinese cabbage growth by alleviating iron deficiency, boosting antioxidant activity, and reducing oxidative stress; further field trials are needed to verify its effectiveness and cost−efficiency. Full article

Magnesia-dolomite refractories have emerged as sustainable alternatives to traditional carbon- or chromium-containing linings in steelmaking and cement industries. Their outstanding thermochemical stability, high refractoriness, and strong basic slag compatibility make them suitable for converters, electric arc furnaces (EAF), and argon–oxygen decarburization (AOD) units. However, their practical application has long been constrained by hydration and thermal shock sensitivity associated with free CaO and open porosity. Recent advances, including optimized raw material purity, fused co-clinker synthesis, nano-additive incorporation (TiO₂, MgAl₂O₄ spinel, FeAl₂O₄), and improved sintering strategies, have significantly enhanced density, mechanical strength, and hydration resistance. Emerging technologies such as co-sintered magnesia–dolomite composites and additive-assisted microstructural tailoring have enabled superior corrosion resistance and extended service life. This review provides a comprehensive analysis of physicochemical mechanisms, processing routes, and industrial performance of magnesia–dolomite refractories, with special emphasis on their contribution to technological innovation, decarbonization, and circular economy strategies in high-temperature industries. Full article

This study presents a comprehensive investigation into the large-scale production of synthetic and hybrid (nanoparticle-loaded) nanofibers using needleless electrospinning. A diverse range of polymers, including polyamide 6 (PA6) and its other polymer combinations, recycled PA6, polyamide 11 (PA11), polyamide 12 (PA12), polyvinyl butyral (PVB), polycaprolactone (PCL), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polyurethane (PU), polyvinyl alcohol (PVA), and cellulose acetate (CA), were utilized to fabricate nanofibers with tailored properties such as polymer solution concentrations and various solvent systems. Furthermore, an extensive variety of nano- and micro-particles, including TiO₂, ZnO, MgO, CuO, Ag, graphene oxide, CeO₂, Er₂O₃, WO₃, MnO₂, and hyperbranched polymers, were incorporated into the polymeric systems to engineer multifunctional nanofibers with enhanced structural characteristics. The study examines the impact of polymer–nano/micro-particle interactions, fiber morphology, and the feasibility of large-scale production via needleless electrospinning. The resulting nanofibers exhibited diameters starting from 80 nm, depending on the polymer and processing conditions. The incorporation of TiO₂, CeO₂, WO₃, Ag, and ZnO nanoparticles into 15% PA6 solutions yielded well-dispersed hybrid nanofibers. By providing insights into polymer selection, nano- and micro-particle integration, and large-scale production techniques, this work establishes a versatile platform for scalable hybrid nanofiber fabrication, paving the way for innovative applications in nanotechnology and materials science. Full article