Search Results (95)

The imperative for high-performance protective materials has catalyzed the rapid evolution of polyurea (PUA) coatings, widely recognized for their mechanical robustness, chemical resistance, and rapid-curing properties. However, their inherent flammability and harmful combustion byproducts pose significant challenges for safe use in applications where fire safety is a critical concern. In response, significant efforts focus on improving the fire resistance of PUA materials through chemical modifications and the use of functional additives. The review highlights progress in developing flame-retardant approaches for PUA coatings, placing particular emphasis on the underlying combustion mechanisms and the combined action of condensed-phase, gas-phase, and interrupted heat feedback pathways. Particular emphasis is placed on phosphorus-based, intumescent, and nano-enabled flame retardants, as well as hybrid systems incorporating two-dimensional nanomaterials and metal–organic frameworks, with a focus on exploring their synergistic effects in enhancing thermal stability, reducing smoke production, and maintaining mechanical integrity. By evaluating current strategies and recent progress, this work identifies key challenges and outlines future directions for the development of high-performance and fire-safe PUA coatings. These insights aim to guide the design of next-generation protective materials that meet the growing demand for safety and sustainability in advanced engineering applications. Full article

In this study, we aimed to investigate the effects of coagulants and dissolved organic matter (DOM) on the biological toxicity of nano-zinc oxide (nZnO) to key microorganisms involved in biological phosphorus removal during sewage treatment. Polyaluminum chloride and polyferric chloride were selected as coagulants, whereas fulvic acid, glucose, and aspartic acid represented the DOM. The mechanisms through which these chemicals influence nZnO toxicity were also investigated. The results show that polyaluminum chloride and polyferric chloride effectively reduced nZnO toxicity in phosphorus-accumulating organisms, demonstrating their detoxification effects. Similarly, fulvic acid and glucose mitigated nZnO toxicity, whereas aspartic acid displayed dual effects: detoxification at low concentrations and enhanced toxicity at high concentrations. These findings highlight the dual role of sewage treatment additives in enhancing traditional pollutant removal and mitigating the nanoparticle-induced inhibition of microbial biochemical processes. This study clarified the interactions between coagulant chemicals, DOM, and nanoparticles in sewage treatment, offering insights into the regulatory mechanisms that improve treatment efficacy and reduce ecological risks. Full article

Accurate predictions of elastic properties under varying doping concentrations and temperatures are critical for designing reliable silicon-based micro-/nano-electro-mechanical systems (MEMS/NEMS). Empirical potentials typically lack accuracy for elastic predictions, whereas density functional theory (DFT) calculations are precise but computationally expensive. In this study, we developed a highly accurate and efficient machine learning-based Deep Potential (DP) model to predict the elastic constants of phosphorus-doped silicon (Si_64−xP_x, x = 0, 1, 2, 3, 4) within a temperature range of 0–500 K. The DP model was rigorously validated against benchmark DFT results. At 0 K, the elastic constants predicted by our DP model exhibited excellent agreement with experimental data, achieving a mean absolute percentage error (MAPE) of only 2.88%. We investigated the effects of doping on elastic constants in single-crystal silicon and determined their second-order temperature coefficients. The calculations demonstrated distinct doping-induced variations, showing pronounced decreases in C₁₁ and C₄₄ and a moderate increase in C₁₂. Finite-element analyses using the fitted temperature coefficients indicated improved thermal stability of silicon resonators through phosphorus doping. Our study explores the integration of machine learning-based atomic-scale simulations with MEMS/NEMS design, providing practical guidance for optimal dopant selection to enhance silicon resonator thermal stability. Full article

Dimethyl methylphosphonate (DMMP) and modified nano-silica were utilised to enhance the mechanical properties, thermal stability, and flame retardancy of waterborne polyurethane (WPU). Nano-silica modified with the silane coupling agent γ-aminopropyltriethoxysilane (KH550) exhibited excellent dispersibility and stability. Compared with pure WPU, the limiting oxygen index (LOI) of P/Si-WPU increased from 18.1% to 28.3%, and its UL-94 rating reached V-0, with a significant improvement in elongation at break. Furthermore, the peak heat release rate of P/Si-WPU decreased by 29.1%, while the total heat release was reduced by 6.8% in comparison to pure WPU. The synergistic flame-retardant mechanism of phosphorus and silicon was investigated through an analysis of the char residue of WPU and its composites. This study provides a potential approach for the development of WPU with superior flame retardancy and enhanced mechanical properties. Full article

Nickel–phosphorus (NiP) alloys have been widely used in many engineering fields such as aerospace, automotive, and optics; however, it is difficult to study the material removal mechanism and microscopic size changes in the polishing process of nickel–phosphorus alloys through simple experiments. In light of these difficulties, there is a need to improve our understanding of the surface friction and wear mechanisms of NiP materials. In the present study, molecular dynamics simulations are employed for the first time to investigate the material removal mechanism, mechanical response, phase transformation, and stress distribution of two NiP alloys with different phosphorus contents during the nano-polishing process by adjusting the polishing depth and speed. Our simulation results indicate that the mechanical response of the low-phosphorus alloy is slightly higher than that of the high-phosphorus NiP alloy. Larger polishing depths and higher speeds reduce the surface quality and lead to increased residual stress. The findings presented herein provide an atomic-level understanding of the material removal mechanism of NiP alloys via MD methodology and offer valuable guidance for selecting alloys with an appropriate NiP ratio as engineering materials and for developing processing methods to improve surface quality. Full article

The objective of this study was to examine the impact of various foliar fertilization treatments on the growth of new shoots, photosynthetic characteristics of leaves, and mineral nutrient content in the leaves of ‘Marselan’ grapevines. Five distinct combinations of nano zero-valent iron (n ZVI), compound sodium nitrophenolate (CSN), and potassium dihydrogen phosphate (KH₂PO₄) were administered through foliar application to ‘Marselan’ grapevines cultivated in the Wuwei region of the Hexi Corridor, with water spray serving as the control treatment. The results showed that T5 treatment (15 mg·L⁻¹ n ZVI + 0.4 g·L⁻¹ CSN + 2.5 g·L⁻¹ KH₂PO₄) significantly increased the leaf area and SPAD value of ‘Marselan’ grapes; T4 treatment (15 mg·L⁻¹ n ZVI + 0.4 g·L⁻¹ CSN + 1.67 g·L⁻¹ KH₂PO₄) significantly increased the internode length of new grape shoots. T5 treatment was favorable to increase the basic coarseness of new grape shoots, the net photosynthetic rate of the leaves, and stomatal conductance; leaf transpiration rate was the highest under the T4 and T5 treatments; T3 (15 mg·L⁻¹ n ZVI + 0.4 g·L⁻¹ CSN + 1.25 g·L⁻¹ KH₂PO₄), T4, and T5 treatments could improve leaf initial fluorescence at different periods. At 45 days after flowering, the maximum photochemical efficiency under the T3 and T4 treatments reached the highest value throughout the period, and the T3 treatment improved leaf potential maximum quantum yield. Meanwhile, the leaf nitrogen and phosphorus content under the T5 treatment were the highest in the five periods. Additionally, the contents of potassium (K), manganese (Mn), copper (Cu), and zinc (Zn) in the leaves increased significantly under the T4 and T5 treatments. The following conclusions emerged from a comprehensive analysis: the T4 treatment was the best, and the T5 treatment was the second most effective. Full article

Calcareous soils, prevalent in arid and semi-arid regions, often limit agricultural productivity due to their alkaline nature and poor nutrient availability. This study assessed the effects of mineral sulfur (312 kg ha⁻¹), nano-sulfur (12, 24, and 36 kg ha⁻¹), and compost (4.8 tons ha⁻¹) on the physical and chemical properties of saline calcareous soils and their impact on maize and wheat yields. The field experiment on new extended agriculture in Mallawy, Egypt, utilized a randomized complete block design. The results showed that nano-sulfur treatments outperformed mineral sulfur. Specifically, the combination of 36 kg ha⁻¹ nano-sulfur with 4.8 tons ha⁻¹ compost improved key soil physical properties, including bulk density, porosity, and hydraulic conductivity. This treatment also significantly reduced soil pH, electrical conductivity, and exchangeable sodium while enhancing the availability of essential nutrients such as nitrogen (N), phosphorus (P), potassium (K), and total sulfate (SO₄²⁻). These enhancements in soil health led to notable increases in both maize and wheat yields, as well as better crop nutrient uptake. The findings suggest that nano-sulfur, when used in conjunction with compost, is a highly effective amendment for improving the health of saline calcareous soils, enhancing crop productivity, and promoting sustainable agricultural practices in arid and semi-arid regions. This combination provides a promising alternative to excessive chemical fertilizers, fostering soil health and long-term agricultural sustainability. Full article

Livestock and poultry waste liquid contains a lot of nitrogen, phosphorus, and microorganisms, and direct discharge causes great harm to the environment. Chicken manure was selected as the research object, and nanoparticle nano-Fe₂O₃, nano-C₆₀, antibiotics enrofloxacin, sulfamethoxazole, and oxytetracycin were selected as additives to carry out medium-temperature sequential batch anaerobic digestion experiment. The experiment lasted for 55 days. The results showed that (1) gas production reached its peak in the first 1–2 days of a single stress experiment, and the cumulative gas production in the first 10 days was as follows: R5 > R4 > R3 > R2 > CK > R1; (2) the concentrations of total volatile fatty acids (TVFAs) in the groups increased rapidly from day 1 to 10, and the concentrations of TVFAs in the nano-Fe₂O₃ and nano-C₆₀ groups were higher than those in the other four groups. The pH of the system decreased, and the soluble chemical oxygen demand (SCOD) was consistent with the trend of TVFAs, while the pH of the nanoparticle group was lower; (3) changes in the horizontal structure of bacterial community of Firmicutes and Bacteroidetes were dominant bacteria in each group on the first day. On day 5, the relative abundance of actinomycetes and Bacteroidetes increased significantly. This experiment contributes to the study of the effects of adding nanoparticles and antibiotics to anaerobic digestion substrates on gas production characteristics, provides data support, and characterizes the microbial situation during digestion. This paper can help to realize carbon emission reduction in agriculture and rural areas. Based on the above background, a self-designed system for testing the anaerobic digestion potential of methane was used in this study using chicken manure. Based on the single pollutant stresses of nano-Fe₂O₃, nano-C₆₀, enrofloxacin, sulfamethoxazole, and hygromycin, the effects of different pollutants under independent stresses on methane production and the changes in the performance of the anaerobic digestion system for gas production were investigated. The chemical parameters and microbial diversity in the anaerobic digestion process were analyzed, and the effects of different nanoparticles and antibiotics on the anaerobic system of chicken manure were elucidated. The results of the study can provide data support for the stable operation of biogas projects, which is of great significance in promoting the sustainable development of ecological agriculture. Full article

Existing studies have demonstrated the positive effects of nano-sized iron oxide on compost maturity, yet the impact of nano-sized iron oxide on phosphorus speciation and bacterial communities during the composting process remains unclear. In this study, pig manure and straw were used as raw materials, with biochar-supported nano-sized iron oxide (BC-Fe₃O₄NPs) as an additive and calcium peroxide (CaO₂) as a co-agent, to conduct an aerobic composting experiment with pig manure. Four treatments were tested: CK (control), F1 (1% BC-Fe₃O₄NPs), F2 (5% BC-Fe₃O₄NPs), and F3 (5% BC-Fe₃O₄NPs + 5% CaO₂). Key findings include the following. (1) BC-Fe₃O₄NPs increased compost temperatures, with F3 reaching 61℃; F1 showed optimal maturity (C/N ratio: 12.90). (2) BC-Fe₃O₄NPs promoted stable phosphorus forms; Residual-P proportions were higher in F1, F2, and F3 (25.81%, 51.16%, 51.68%) than CK (19.32%). (3) Bacterial phyla Firmicutes, Actinobacteria, and Proteobacteria dominated. BC-Fe₃O₄NPs altered community composition, especially on day 7. Firmicutes dominated CK, F1, and F3; Proteobacteria dominated F2. At the genus level, day 7 showed Corynebacterium (CK), Clostridum (F1, F3), and Caldibacillus (F2) as predominant. (4) Pearson correlation analysis revealed shifted correlations between phosphorus forms and bacterial phyla after BC-Fe₃O₄NPs addition. Firmicutes positively correlated with NaOH-OP in F1 during the thermophilic phase, facilitating phosphate release and adsorption by BC-Fe₃O₄NPs. The significance of correlations diminished with increasing additive concentration; in F3, all phyla positively correlated with various phosphorus forms. Full article

This study aimed to explore the combined effects of micro-nano bubble water drip irrigation and different phosphorus (P) application rates (P0: 0 kg·hm⁻²; P1: 86 kg·hm⁻²; P2: 172 kg·hm⁻²; P3: 258 kg·hm⁻²) on maize growth, soil phosphorus dynamics, and phosphorus use efficiency to optimize irrigation and P fertilizer use efficiency. Through a field column experiment, the impact of micro-nano bubble water drip irrigation on maize plant height, stem diameter, leaf SPAD values, biomass, and yield was evaluated. The results showed that (1) irrigation methods significantly affected maize growth indicators such as plant height, stem diameter, and root dry weight. Micro-nano bubble water drip irrigation consistently promoted growth during all growth stages, especially under higher P application. (2) P application significantly increased the dry weight and P concentration in maize roots, stems, leaves, ears, and grains. Under micro-nano bubble water drip irrigation, the P concentrations in roots and grains increased by 59.28% to 92.59%. (3) Micro-nano bubble water drip irrigation significantly enhanced P uptake efficiency, partial factor productivity of P, and agronomic P use efficiency. Particularly under P1 and P2 treatments, the increases were 134.91% and 45.42%, respectively. Although the effect on apparent P recovery efficiency was relatively small, micro-nano bubble water drip irrigation still improved P utilization under moderate P levels. (4) Structural equation modeling indicated that P supply under micro-nano bubble water drip irrigation primarily regulated alkaline protease and alkaline phosphatase, enhancing soil P availability, which in turn promoted maize P accumulation and increased yield. In conclusion, this study demonstrated that the combination of micro-nano bubble water drip irrigation and appropriate P application can effectively promote maize growth and nutrient utilization, providing a theoretical basis for optimizing irrigation and fertilization strategies in maize production. Full article

Magnesium alloy ZK60 shows great promise as a medical metal material, but its corrosion resistance in the body is inadequate. Hydroxyapatite (HA), the primary inorganic component of human and animal bones, can form chemical bonds with body tissues at the interface, promoting the deposition of phosphorus products and creating a dense calcium and phosphorus layer. To enhance the properties of ZK60, HA was added to create HA/ZK60 composite materials. These composites, fabricated using the advanced technique of LPBF, demonstrated superior corrosion resistance and enhanced bone inductive capabilities compared to pristine ZK60. Notably, the incorporation of 3 wt% led to a significant reduction in bulk porosity, achieving a value of 0.8%. The E_corr value increased from −1.38 V to −1.32 V, while the minimum I_corr value recorded at 33.9 μA·cm⁻². Nano-HA achieved the lowest volumetric porosity and optimal corrosion resistance. Additionally, these composites significantly promoted osteogenic differentiation in bone marrow stromal cells (BMSCs), as evidenced by increased alkaline phosphatase (ALP) activity and robust calcium nodule formation, highlighting their excellent biocompatibility and osteo-inductive potential. However, when increasing the HA content to 6 wt%, the bulk porosity rose significantly to 3.3%. The E_corr value was −1.3 V, with the I_corr value being approximately 50 μA·cm⁻². This increase in porosity and weaker interfacial bonding, ultimately accelerated electrochemical corrosion. Therefore, a carefully balanced amount of HA significantly enhances the performance of the ZK60 magnesium alloy, while excessive amounts can be detrimental. Full article

This study investigated the effects of nano zero-valent iron-modified biochar (nZVI@BC) as a soil amendment on potted rice growth, soil properties, and heavy metal dynamics. Seven treatments with varying amounts of soil conditioner, biochar, and nZVI@BC were applied to potted rice. Results showed that nZVI@BC application significantly improved rice agronomic traits, with the 15 g·kg⁻¹ treatment increasing the panicle formation rate by 15% and 100-grain weight by 8% compared to the control. Soil fertility was enhanced, with available phosphorus increasing from 137 to 281 mg·kg⁻¹ in the most effective treatment. Heavy metal analysis revealed that nZVI@BC application did not increase soil heavy metal content, with Cd levels remaining below 0.3 mg·kg⁻¹ across treatments. Notably, the 10 g·kg⁻¹ nZVI@BC treatment showed potential for slight Cd immobilization, reducing its concentration from 0.32 to 0.26 mg·kg⁻¹. Microbial community analysis showed that nZVI@BC altered soil microbial diversity and composition, with the 10 g·kg⁻¹ treatment resulting in the highest fungal diversity (Chao1 index: 294.219). The relative abundance of the beneficial fungal class Agaricomycetes increased from 40% to 55% with optimal nZVI@BC application. These findings suggest that nZVI@BC has potential as an effective soil amendment for improving rice cultivation while maintaining soil health, microbial diversity, and potentially mitigating heavy metal contamination. Full article

After the period of halogenated compounds, the period of nano-structured systems, and that of phosphorus (and nitrogen)-based additives (still in progress), following the increasingly demanding circular economy concept, about ten years ago the textile flame retardant world started experiencing the design and exploitation of bio-sourced products. Indeed, since the demonstration of the potential of such bio(macro)molecules as whey proteins, milk proteins (i.e., caseins), and nucleic acids as effective flame retardants, both natural and synthetic fibers and fabrics can take advantage of the availability of several low-environmental impact/“green” compounds, often recovered from wastes or by-products, which contain all the elements that typically compose standard flame-retardant recipes. The so-treated textiles often exhibit flame-retardant features that are similar to those provided by conventional fireproof treatments. Further, the possibility of using the same deposition techniques already available in the textile industry makes these products very appealing, considering that the application methods usually do not require hazardous or toxic chemicals. This review aims to present an overview of the development of bio-sourced flame retardants, focusing attention on the latest research outcomes, and finally discussing some current challenging issues related to their efficient application, paving the way toward further future implementations. Full article

Phosphorus (P) recovery from wastewater is considered to be a positive human intervention towards sustainable P use in the global P cycle. This study investigated the feasibility of synthesizing a superparamagnetic nano-sorbent that was functionalized by lanthanum silicate nanorods (NR_La-Si) using drinking water treatment sludge (DWTS), evaluating both its P adsorption capacity and fertilization effect. The DWTS-based La-modified P nano-sorbent (P-sorbent _D) exhibited complicated but single-layer-dominant adsorption for phosphate, with a maximum adsorption capacity up to 26.8 mg/g, which was superior to that of most of the similar sludge-based P-sorbent. The NR_La-Si-modified P-sorbent _D was identified with several characterization techniques and the leaching metal elements from the nano-sorbent were tested, which were below the limits proposed by the Food and Agriculture Organization of the United Nations. In addition, the growth and vigorousness of Arabidopsis thaliana indicated that the exhausted P-sorbent _D could be used as a potential water-soluble moderate-release P fertilizer, which was also confirmed by the well-fitted P uptake model and the P desorption pattern from the sorbent–fertilizer. The doped lanthanum silicate nanorods could play the dual role of P complexation enhancement and health/growth promotion. In light of this, this study proposed a new way of reclaiming DWTS as a P-sorbent for fertilization, offering new insights into the path toward “closing the P loop”. Full article