Search Results (41)

Polystyrene (PS) is widely used yet highly flammable, and developing halogen-free flame retardants that ensure both high fire safety and mechanical performance remains a challenge. A green intumescent system comprising ammonium dihydrogen phosphate (ADP) and phytic acid–triethylenetetramine (PA–TETA) was incorporated into PS powder via sequential solution grinding and hot pressing. The optimal formulation, PS/10ADP/15PA–TETA, achieved a limiting oxygen index of 28.5% with a UL-94 V-0 rating, and reduced the peak heat release rate and total heat release by 73.8% and 46.2%, respectively, while retaining 78.4% of the tensile strength of neat PS. The ADP/PA–TETA system operates via a cooperative condensed-phase charring and gas-phase dilution mechanism, achieving superior flame retardancy in PS composites. This work provides an effective and eco-friendly strategy for fabricating high-performance PS composites with balanced flame retardancy and mechanical properties. Full article

The aim of this study was to synthesize, characterize, and investigate the biomedical effects of nanoscale cerium phosphate obtained via different synthesis techniques, as well as to evaluate the influence of various CePO₄ concentrations on cells involved in skin structure regeneration (human mesenchymal stem cells, keratinocytes, and fibroblasts) and establish their antioxidant properties. Methods and Results: Cerium(III) orthophosphate was obtained by precipitation with ammonium dihydrogen phosphate from a nitrate solution. By changing the initial concentrations of the solutions and the drying and annealing temperatures, the best conditions for obtaining nanosized phosphate powders were established. The structure of rhabdophane was obtained by X-ray diffraction analysis, and the particle sizes were measured by transmission electron microscopy. The particle sizes ranged from 2 to 10 nm in the transverse direction and 20 to 50 nm in the longitudinal direction. Studies on cell lines have shown a high level of safety, as well as the regenerative potential of CePO₄ nanoparticles, which have a stimulating effect on the proliferation of MSCs at concentrations of 10⁻² to 10⁻³ M for 48 h after application and stimulate the metabolism of human keratinocytes and fibroblasts at a wide range of concentrations (10⁻³ to 10⁻⁵ M). A dose-dependent antioxidant effect of small CePO₄ nanoparticles at a concentration of 10⁻² to 10⁻⁵ has been established, which is stronger than ascorbic acid. Conclusions: A method for obtaining cerium phosphate nanoparticles with beneficial biomedical effects was developed. The non-cytotoxicity and regenerative potential of CePO₄ were established at a wide range of concentrations on different cell lines that are involved in the healing of skin wounds, as were their antioxidant properties. Full article

The flammability and volatility of conventional lithium hexafluorophosphate (LiPF₆)-based electrolytes with organic carbonate solvents remain critical issues to the safety and thermal stability of lithium-ion batteries (LIBs). This study investigates the incorporation of phosphate-based additives including ammonium dihydrogen phosphate (ADP), trimethyl phosphate (TMP), and trimethyl phosphite (TMPi) into LiPF₆ electrolytes for improving the ionic conductivity, safety, and electrochemical performance of LIBs. Self-extinguishing time (SET) measurements demonstrated that the ADP-based LiPF₆ electrolyte significantly reduced flammability, achieving a shorter SET of 04 min 53 s, compared to 12 min for the pristine LiPF₆ electrolyte. The ADP-based LiPF₆ electrolyte possessed the highest ionic conductivity (14.08 mS·cm⁻¹) with an excellent lithium-ion transference number of 0.0076. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (C-V) analyses demonstrated that ADP lowered interfacial resistance and stabilized long-term cycling behavior. In particular, the 1% ADP-based LiPF₆ electrolyte maintained improved charge-discharge profiles and Coulombic efficiency over 200 cycles. These results highlight ADP’s dual functionality in suppressing gas-phase flammability and enhancing condensed-phase electrochemical stability, making it a promising candidate for next-generation, high-safety, high-performance LIB electrolytes. Full article

Titanium alloys are frequently subjected to surface treatments to enhance their biocompatibility and corrosion resistance in biological environments. Plasma electrolytic oxidation (PEO) is an environmentally friendly electrochemical technique capable of forming oxide layers characterized by high corrosion resistance, biocompatibility, and strong adhesion to the substrate. In this study, the PEO process was performed using a low-melting-point ternary eutectic electrolyte composed of Ca(NO₃)₂–NaNO₃–KNO₃ (41–17–42 wt.%) with the addition of ammonium dihydrogen phosphate (ADP). The use of this electrolyte system enables a reduction in the operating temperature from 280 to 160 °C. The effects of applied voltage from 200 to 400V, current frequency from 50 to 1000 Hz, and ADP concentrations of 0.1, 0.5, 1, 2, and 5 wt.% on the growth of titanium oxide composite coatings on a Ti-6Al-4V substrate were investigated. The incorporation of Ca and P was confirmed by phase and chemical composition analysis, while scanning electron microscopy (SEM) revealed a porous surface morphology typical of PEO coatings. Corrosion resistance in Hank’s solution, evaluated via Tafel plot fitting of potentiodynamic polarization curves, demonstrated a substantial improvement in electrochemical performance of the PEO-treated samples. The corrosion current decreased from 552 to 219 nA/cm², and the corrosion potential shifted from −102 to 793 mV vs. the Reference Hydrogen Electrode (RHE) compared to the uncoated alloy. These findings indicate optimal PEO processing parameters for producing composite oxide coatings on Ti-6Al-4V alloy surfaces with enhanced corrosion resistance and potential bioactivity, which are attributed to the incorporation of Ca and P into the coating structure. Full article

Magnesium whitlockite (Mg-WH) has emerged as a promising biomaterial for bone regeneration due to its compositional similarity to natural bone minerals. This study aimed to systematically modify a dissolution–precipitation synthesis method to produce Mg-WH granules with tailored morphologies and controlled phase compositions for possible use in bone regeneration applications. Three distinct precursor granules were prepared by mixing varying amounts of ammonium dihydrogen phosphate and magnesium hydrogen phosphate with calcium sulfate. The precursors were then transformed into biphasic and single-phase Mg-WH granules by means of immersion in magnesium- and phosphate-containing solutions under controlled conditions. The X-ray diffraction results demonstrated that biphasic materials containing Mg-WH and either calcium-deficient hydroxyapatite (CDHA) or dicalcium phosphate anhydrous (DCPA) formed after 24 h of synthesis, depending on the synthesis conditions. Prolonging the reaction time to 48 h resulted in complete transformation into single-phase Mg-WH granules. Fourier-transform infrared spectroscopy confirmed the presence of functional groups characteristic of Mg-WH, CDHA, and DCPA in the intermediate products. The spectra also indicated the absence of precursor phases and the progressive elimination of secondary phases as the reaction time increased. Scanning electron microscopy analyses revealed notable morphological transformations from the raw granules to the product granules, with the latter exhibiting interlocked spherical and rod-like particles composed of fine Mg-WH rhombohedral crystals. N₂ adsorption–desorption analyses exposed significant differences in the surface properties of the synthesized granules. By varying precursor, reaction solution compositions, and reaction times, the study elucidated the phase evolution mechanisms and demonstrated their impact on the structural, morphological, and surface properties of Mg-WH granules. Full article

This research focuses on finding an environmentally friendly method for extracting gold from a sulfide flotation concentrate. In this study, an ammonia–copper–thiosulfate leaching system was utilized for the extraction of gold. The flotation concentrate sample contains about 190 ppm of gold, 160 ppm of silver, and 6.89% of copper. To achieve an optimized gold extraction, various parameters, such as thiosulfate, ammonia and copper concentrations, pulp density, pH, stirring rate, temperature, and time, were investigated. About 87% of gold was leached under the following conditions: 0.5 M S₂O₃²⁻, 1.0 M NH₃, 0.1 M Cu²⁺, a stirring rate of 350 rpm, a pH of 12, a pulp density of 10% solids, a temperature of 25 °C, and a leaching time of 2 h. Additionally, to improve the economic effectiveness of the leaching system, thiosulfate consumption was investigated by utilizing different additives, such as diethylenetriamine (DETA), glycerol, and ammonium dihydrogen phosphate (ADP). The results showed that with the use of ADP, gold extraction increased from 87% to 91% while reducing copper dissolution. Additionally, the thiosulfate consumption also decreased from 0.37 M to 0.3 M. The inclusion of ADP was particularly effective, enhancing gold extraction efficiency and reducing reagent consumption, thereby making the process more sustainable. Considering the high economic value of gold, the optimization of recovery efficiency is prioritized over reagent costs in this study. Overall, this study indicates that the optimized ammonia–copper–thiosulfate leaching system with ADP additive is a promising environmentally friendly method for the extraction of gold. Full article

In this study, nanoparticles with a monoclinic crystal structure of Gd_0.85−yLa_yPO₄:15%Eu were synthesized through a hydrothermal method. Initial investigations focused on the influence of the precursor on the resulting structure of LaPO₄:1%Eu, with variations in synthesis temperature. Various syntheses were conducted using ammonium dihydrogen phosphate (NH₄H₂PO₄) and diammonium hydrogen phosphate ((NH₄)₂HPO₄) as PO₄³⁻ ion precursors, and the synthesis temperature ranged from room temperature to 200 °C. Based on the synthesis and analysis outcomes, diammonium hydrogen phosphate was selected as the precursor for PO₄³⁻ ions. Subsequent hydrothermal synthesis was performed at 180 °C to produce nanoparticles with a monoclinic crystal structure. After evaluating the synthesis and analysis results, the decision was made to increase the Eu³⁺ content from 1% to 15% by replacing La or Gd when a single-phase La_0.75Gd_0.24PO₄:1%Eu with a monoclinic crystal structure was achieved. These structural modifications were carried out in order to stabilize the anhydrous monoclinic structure and improve the luminescence properties of the phosphate. The synthesized samples were characterized using X-ray diffraction and scanning electron microscopy. Luminescence properties were meticulously measured and discussed. The emission intensity of monoclinic structure La_0.75Gd_0.1PO₄:15%Eu was found to be almost twice as high as compared with La_0.61Gd_0.24PO₄:15%Eu. Additionally, magnetization dependence on the applied magnetic field strength was measured, revealing paramagnetic properties in the investigated samples. Full article

Buchwaldoboletus xylophilus is an edible bolete species belonging to the family Boletaceae and the genus Buchwaldoboletus. It is found in tropical and subtropical regions, which are known for their rare wild resources. In this study, wild B. xylophilus was isolated and cultured, and its biological characteristics and artificial cultivation techniques were studied. The results show that the optimal carbon source, nitrogen source, and inorganic salt for the mycelium growth of B. xylophilus were maltose, ammonium tartrate, and magnesium sulfate, respectively. The most appropriate temperature was 28 °C, and the pH value was between 5 and 6. The most effective combination was determined via orthogonal experimentation, as follows: dextrose, ammonium nitrate, potassium dihydrogen phosphate, and 28 °C. The results of artificial cultivation in mushroom houses show that the mycelium of B. xylophilus was strong and grew well on the culture medium. The mycelial growth rate was 4.54 mm/d, and the fungus bags were filled about 50 days after inoculation. The primordia formed 9 to 14 days after covering with soil and the fruiting body matured in 6~8 days. The average yield of fresh mushrooms reached 131.07 ± 29.38 g/bag, and the average biological efficiency reached 28.48 ± 6.39%. In this study, artificial cultivation technology in respect of B. xylophilus in mushroom houses is reported for the first time. The fruiting bodies obtained through cultivation were identified using morphological and molecular biological methods. This technology offers benefits such as affordability, a brief cultivation cycle, substantial yields, and superior quality, making it ideal for industrial-scale and extensive cultivation. Full article

Drip irrigation with a fertilizer application could effectively alleviate the soil pollution caused by excessive phosphorus fertilizer. Phosphate fertilizer was dissolved in water and produced a chemical reaction with the ions in irrigation water. The new precipitates were generated, which caused more severe and complex blockage of drip irrigation emitters. Songhua River water was selected as the irrigation water. The experiment investigated the effects of three types of phosphorus fertilizers (urea phosphate, UP; potassium dihydrogen phosphate, PDP; ammonium polyphosphate, APP) and the concentrations (0.2, 0.3, and 0.4 g/L) on the blockage of drip irrigation emitter. The results showed that three types of phosphorus fertilizers intensified the degree of blockage compared with no fertilization, the order from small to large being UP < PDP < APP. The degree of blockage was directly proportional to the concentration of phosphate fertilizer. The system discharge variation ratio (Dra) under UP, PDP, and APP treatments decreased by an average of 6.2~27.7%, 13.8~33.8%, and 21.5~44.6%, respectively. The Christiansen coefficient of uniformity (CU) decreased by an average of 5.9~23.5%, 10.3~27.9%, and 19.1~38.2%. The UP was superior to PDP and APP from the perspective of drip irrigation evaluation indicators. The main reason was that UP reduced the pH value of the water source and inhibited the generation of carbonates. The APP was unable to lower the pH value and had the most serious blockage. The APP was coupled with three concentrations of Mn²⁺ (1, 2, and 3 mg/L) for drip irrigation, which could optimize the blockage problem and explore the efficacy of Mn²⁺. The 2 mg/L Mn²⁺ could maximize the drip irrigation efficiency of the APP. The average increase in Dra and CU was 24.57% and 18.54% macroscopically. Mn²⁺ could alter the lattice parameters of carbonates and had a certain impact on their size and morphological distribution on a microscopic level. The results showed that fertilization with UP at a concentration of 0.2 g/L did not significantly exacerbate clogging. The drip irrigation effect of Songhua River water combined with 0.2 g/L concentration UP was the best. Moreover, 2 mg/L of Mn²⁺ was proposed to alleviate the clogging characteristics of APP4. This study could provide reference for improving the efficiency of the Songhua River drip irrigation system. Full article

The use of traditional sealing materials in buildings poses a significant risk of fire and noise pollution. To address these issues, we propose a novel composite functional sealant designed to enhance fire safety and sound insulation. The sealant incorporates a unique four-component filler system consisting of carbon nanotubes (CNTs) decorated with layered double hydroxides (LDHs), ammonium dihydrogen phosphate (ADP), and artificial marble waste powder (AMWP), namely CLAA. The CNTs/LDHs framework provides structural support and enhances thermal stability, while the ADP layer acts as a protective barrier and releases non-combustible gases during combustion. AMWP particles contribute to sound insulation by creating impedance mismatches. The resulting composite functional sealant exhibits improved mechanical properties. In terms of flame retardancy, it boasts the lowest peak heat release rate (PHRR) of 224.83 kW/m² and total smoke release (TSR) of 981.14 m²/m², achieving the V-0 classification. Furthermore, its thermal degradation characteristics reveal a notably higher carbon residue rate. Additionally, the sound insulation capability has been significantly enhanced, with an average sound insulation level of 43.48 dB. This study provides a promising solution for enhancing the fire safety and acoustic properties of building sealing materials. Full article

Biological control plays an increasingly important role in various aspects of modern agriculture and forestry. Identifying biocontrol strains with commercial potential for effective disease management is currently a focal point in biological control research. In this study, Bacillus atrophaeus XHG-1-3m2, a strain with significant biocontrol potential against Wilsonomyces carpophilus causing shot hole disease in wild apricots, was developed. The study determined the antibacterial activity of the fermentation broth, the optimal fermentation medium composition and conditions, and explored its effectiveness in controlling Wilsonomyces carpophilus. The optimal fermentation medium for strain XHG-1-3m2 comprises 12.5 g/L yeast extract, 12.5 g/L soy peptone, 10.0 g/L sodium chloride, 1 g/L ammonium chloride, 1 g/L potassium dihydrogen phosphate, 1 g/L disodium hydrogen phosphate, and 0.5 g/L magnesium sulfate heptahydrate. With an initial pH of 7.0, a liquid volume of 40%, an inoculum volume of 3%, and shaking incubation at 28 °C for 24 h, the viable cell count reached 14 × 10⁹ CFU/mL. In vitro and in vivo tests on leaves revealed that the fermentation broth and the biocontrol biofertilizer derived from this strain inhibited the leaf lesions caused by Wilsonomyces carpophilus on wild apricots, achieving inhibition rates of 94.62% and 82.46%, respectively. Full article

The doping of porous carbon materials with nitrogen is an effective approach to enhance the electrochemical performance of electrode materials. In this study, nitrogen-doped porous carbon derived from peanut shells was prepared as an electrode for supercapacitors. Melamine, urea, urea phosphate, and ammonium dihydrogen phosphate were employed as different nitrogen dopants. The optimized electrode material PA-1-1 prepared by peanut shells, with ammonium dihydrogen phosphate as a nitrogen dopant, exhibited a N content of 3.11% and a specific surface area of 602.7 m²/g. In 6 M KOH, the PA-1-1 electrode delivered a high specific capacitance of 208.3 F/g at a current density of 1 A/g. Furthermore, the PA-1-1 electrode demonstrated an excellent rate performance with a specific capacitance of 170.0 F/g (retention rate of 81.6%) maintained at 20 A/g. It delivered a capacitance of PA-1-1 with a specific capacitance retention of 98.8% at 20 A/g after 5000 cycles, indicating excellent cycling stability. The PA-1-1//PA-1-1 symmetric supercapacitor exhibited an energy density of 17.7 Wh/kg at a power density of 2467.0 W/kg. This work not only presents attractive N-doped porous carbon materials for supercapacitors but also offers a novel insight into the rational design of biochar carbon derived from waste peelings. Full article

The global phosphate (P) rock shortage has become a significant challenge. Furthermore, the misalignment between crops, soil, and P usage exacerbates P rock wastage in agriculture. The distinctions among various types of phosphorus fertilizers influence the phosphorus cycle, which subsequently impacts biomass, the number of grains per ear, the weight of a thousand grains, and, ultimately, the overall yield. In a four-year field experiment conducted from 2017 to 2021, we assessed the impact of various P fertilizer types on crop yield in a continuous wheat–maize rotation system. Prior to planting the crops, P fertilizers were applied as base fertilizers at a rate of 115 kg P₂O₅ ha⁻¹ during the wheat season and 90 kg P₂O₅ ha⁻¹ during the maize season. Additionally, nitrogen (N) was applied at rates of 120 kg ha⁻¹ for wheat and 180 kg ha⁻¹ for maize. The P fertilizers used included ammonium dihydrogen phosphate, ammonium polyphosphate, calcium–magnesia phosphate, ammonium phosphate, and calcium superphosphate. Urea was used as the N fertilizer with a split application—60% at planting and 40% at the jointing stage for wheat or the V12 (twelve leaf collar) stage for maize. The results showed that different P fertilizers increased the average yield of wheat and maize by 21.2–38.0% and 9.9–16.3%, respectively. It was found that ammonium polyphosphate, calcium superphosphate, and monoammonium phosphate were more suitable for application in a summer maize–winter wheat rotation system on loess soil. Full article

Porous chitosan/hydroxyapatite (Chi-HAp) composite microspheres were prepared in an aqueous solution containing chitosan, calcium nitrate, and ammonium dihydrogen phosphate by using a hydrothermal method at various temperatures. The investigation indicated that temperature significantly impacted the final product’s appearance. Hydroxyapatite (HAp) coupled with dicalcium phosphate dihydrate (DCPD) flakes were obviously found at 65 and 70 °C, while the latter gradually disappeared at higher temperatures. Conversely, synthesis at 90 °C led to smaller particle sizes due to the broken chitosan chains. The microspheres synthesized at 75 °C were selected for further analysis, revealing porous structures with specific surface areas of 36.66 m²/g, pores ranging from 3 to 100 nm, and pore volumes of 0.58 cm³/g. Vancomycin (VCM), an antibiotic, was then absorbed on and released from the microspheres derived at 75 °C, with a drug entrapment efficiency of 20% and a release duration exceeding 20 days. The bacteriostatic activity of the VCM/composite microspheres against Staphylococcus aureus increased with the VCM concentration and immersion time, revealing a stable inhibition zone diameter of approximately 4.3 mm from 24 to 96 h, and this indicated the retained stability and efficacy of the VCM during the encapsulating process. Full article

Flowability greatly affects the application of ultrafine dry powder fire extinguishing systems, while hydrophobicity and acute inhalation toxicity are concerns for fire extinguishing agents. In the present study, we examined the impact of hydrophobic fumed silica on the hydrophobicity and flow properties of ammonium dihydrogen phosphate as the base. Our findings revealed that incorporating 6 wt.% of hydrophobic fumed silica resulted in optimal flowability, accompanied by a hydrophobicity angle of 126.48°. The excessive inclusion of hydrophobic fumed silica impeded powder flow within the ammonium dihydrogen phosphate particles. Furthermore, the investigations indicated that the incorporation of a small quantity of bentonite (0.5 wt.%) amongst the three functional additives—bentonite, magnesium stearate, and perlite—offered further enhancements in powder flowability. In fire extinguishing experiments’ total flooding conditions (1 m³), the designed UDPA exhibited a minimum required extinguishing concentration of merely 41.5 g/m³, which is better than the publicly reported value. Moreover, observations on the well-being of mice subjected to nearly three times the extinguishing concentration at 60 s, 10 min, and 3 days, respectively, demonstrated the absence of acute inhalation toxicity associated with the designed UDPA. Collectively, the developed ultrafine dry powder fire extinguishing agent displayed promising performance and possesses broad applicability. Full article