Search Results (1,933)

In this work, we demonstrate a defect-mediated strategy to fundamentally reprogram the selectivity of ZnO gas sensors through targeted doping with two types of trivalent rare-earth ions. We incorporate yttrium (Y³⁺) and dysprosium (Dy³⁺) into the ZnO host via a high-energy ball-milling (HEBM)-assisted solid-state reaction. On the basis of structural, optical, and spectroscopic characterizations, we demonstrate a significant increase in the oxygen vacancy density and a reduction in the band gap energy. The gas sensing tests revealed a remarkable inversion of selectivity: while doping suppressed the NO₂ response by 86% to 94%, it increased the sensitivity to VOCs. Dy doping produced a selective sensor for ethanol (S = 9.61, 5.62 × selectivity over NO₂), and Y doping produced a selective sensor for acetone (S = 8.27, 2 × selectivity over NO₂). This dopant-specific defect engineering provides a direct pathway to adapt ZnO sensors to the selective detection of VOCs in environmental monitoring. Full article

Valproic acid is a clinically important therapeutic agent whose biological properties have stimulated the development of structurally modified derivatives with improved pharmacological profiles. In the present study, nine amino–valproic acid hybrids were synthesized by a rapid mechanochemical approach using a planetary ball mill under solvent-minimized conditions. The synthesized compounds were formulated in a newly developed deep eutectic solvent composed of urea and propylene glycol (1:4 molar ratio), which was characterized by solvatochromic and Kamlet–Taft analyses. The biological activities of the derivatives were evaluated by hydrogen peroxide scavenging activity (HPSA), hydroxyl radical-scavenging activity (HRSA), and inhibition of albumin denaturation (IAD) assays. Among the investigated compounds, derivative 3h exhibited the highest biological activity, showing IC₅₀ values of 291 µM and 163 µM in the HPSA and HRSA assays, respectively, and the strongest anti-inflammatory activity in the IAD assay. All synthesized derivatives demonstrated lower IC₅₀ values than ibuprofen in the albumin denaturation model. Dose–response relationships were analyzed using four- and five-parameter logistic models, with the 5PL model providing a statistically superior fit to the experimental data. Lipophilicity measurements and in silico studies further supported the favorable physicochemical profile of the synthesized compounds. These results identify compound 3h as the most promising derivative and demonstrate the potential of mechanochemical synthesis for the preparation of biologically active valproic acid hybrids. Full article

High-temperature and high-salinity reservoirs (typically referring here to temperatures ≥ 100 °C and salinities > 100 g/L) impose stringent requirements on chemical flooding and profile-control agents, particularly in terms of thermal stability, salt tolerance, injectivity, and environmental compatibility. In this study, a bio-based composite mobility-control and oil-displacement system was developed by combining carbonized corn-straw particles with the biopolymer scleroglucan. Corn-straw biomass particles were prepared by pyrolysis at 500 °C followed by ball milling for 2 h. Their particle-size distribution, elemental composition, and suspension stability were characterized, and the rheological behavior, thermal and salt tolerance, long-term aging stability, injectivity, plugging performance, and enhanced-oil-recovery efficiency of the composite system were evaluated systematically. The average particle size decreased from 25.6 μm for mechanically ground straw to 2.8 μm after carbonization and ball milling. The H/C atomic ratio of the carbonized particles was 0.31, indicating enhanced aromatization and structural stability. A scleroglucan concentration of 1000 ppm provided a suspension rate of 97%, balancing suspension stability and chemical dosage. The composite system maintained stable viscosity and viscoelasticity from 30 to 130 °C in deionized water, saturated NaCl solution, and saturated CaCl₂ solution, with viscosity loss below 10%. After sealed anaerobic aging at 100 °C for 28 days, the viscosity retention remained above 90%. Sand-pack tests showed stable injectivity in media with permeabilities of 1235 and 2064 mD and a plugging efficiency of 95.7% in a 2846 mD model. In oil-displacement experiments, the composite system increased the final recovery factor from 46.6% for scleroglucan flooding alone to 53.3%, corresponding to an additional 6.7 percentage points. These results demonstrate that the carbonized biomass particle-scleroglucan system has promising thermal stability, salt tolerance, plugging capacity, and oil-displacement performance, providing a potential green strategy for mobility control in harsh reservoir environments. Full article

Wet grinding is an important operation in the technological process of ceramic tile production. The properties of the slurry obtained from grinding (slip) are conditioned by the raw materials (the type and characteristics of raw material in mixture, recipes for mixture), and by the operating parameters in grinding (technical characteristics of mill, type of grinding system, mill charge, grinding media body, grinding time, etc.). The optimal selection of these influential parameters results in satisfactory properties of slip, i.e., in efficient grinding as process operation, and, consequently, in smooth and efficient realisation of subsequent operations in the process, particularly spray drying. At the end of the technological process, the final goal is to obtain a ceramic tile of satisfactory quality. Multi-criteria decision-making (MCDM) is an increasingly applied tool for selecting optimal technological parameters for the purpose of optimisation, problem solving and improvement of technological processes. This paper presents the application of the symmetry point of criterion—ranking alternatives by perimeter similarity (SPC-RAPS) as an MCDM hybrid method for the selection of optimal technological parameters in grinding in the ceramic tile production process. The ranking and selection of alternatives (raw materials, grinding balls and grinding time) were performed according to various criteria. In addition to the technological parameters related to the characteristics of the products from the grinding (slip), and to the technical characteristics of the final product (ceramic tiles), the criteria also included economic parameters (the market price of raw material and specific energy consumption in grinding). The developed mathematical model enabled the selection of the best alternative as a solution for this problem. Full article

Epoxy resin (EP) exhibits pronounced intrinsic brittleness arising from the highly crosslinked network formed after curing, thereby restricting its application in load-bearing structures. Although TiO₂ nanoparticles possess the potential for impact-strength improvement, they are highly prone to aggregation, which compromises stress-transfer efficiency within the composite. To overcome this challenge, a ball-milling strategy is adopted to anchor TiO₂ nanoparticles onto three-dimensional graphene oxide (3DGO), leading to the successful fabrication of a 3DGO@TiO₂ hybrid filler. At an ultralow loading of 0.03 wt%, the 3DGO@TiO₂ epoxy resin composite shows a 221.5% increase in impact strength to 19.55 kJ/m² and 33.53% and 32.34% increases in tensile and flexural strength to 64.32 MPa and 96.17 MPa, respectively, relative to neat EP. Morphological analyses indicate that the 3DGO spatial confinement reduces TiO₂ aggregate characteristic length by 55.1% from 1123 nm to 504 nm. Molecular dynamics simulations show that the hybrid filler decreases fractional free volume to 17.6%, induces denser matrix packing, and increases the calculated physical interfacial energy to 1023 kcal/mol, which is 2.2 times that of the pure TiO₂ epoxy resin system. This work confirms that 3DGO simultaneously optimizes nanofiller dispersion and physical confinement, offering a novel strategy for high-performance epoxy composites at ultralow loadings. Full article

This study investigates the synthesis of La_0.6Ca_0.4FeO₃ (LCF) perovskite via a ball milling method for application in reverse water–gas shift chemical looping (RWGS-CL) for CO₂-to-CO conversion. Unlike conventional wet-chemical routes such as the Pechini method, the ball milling approach offers a solvent-free, scalable synthesis using low-cost metal oxide precursors (e.g., La₂O₃, CaO, Fe₂O₃). Structural analysis by XRD confirmed the successful formation of single-phase cubic perovskite, with no secondary phases when using oxide precursors. Crystallite size increased with calcination temperature, from 118.9 Å (no calcination) to 404.3 Å (1050 °C). BET analysis revealed a decrease in surface area from 2.5 m²/g (no calcination) to 0.51 m²/g (1050 °C), consistent with sintering at higher temperatures. TPR-H₂ and TPO-CO₂ studies revealed that non-calcined LCF possesses slightly enhanced redox properties, with oxygen vacancy formation and CO₂ reoxidation activity both at 500 °C. RWGS-CL experiments demonstrate that all LCF samples exhibit stable CO production (910–970 µmol/g_LCF) over multiple cycles at 500 °C, with comparable performance across calcination conditions. A cost and sensitivity analysis reveals that the ball milling method had lower synthesis costs by approximately 92% at the laboratory-scale and 88% at the industrial-scale compared to the Pechini method, highlighting its strong potential for large-scale perovskite production. Full article

A nanostructured Ti_0.8V_0.2C solid solution carbide was successfully synthesized via high-energy mechanical alloying (MA) of elemental Ti, V, and C powders for 20 h in a planetary ball mill under argon atmosphere. Phase evolution and microstructural transformation were tracked using XRD, SEM/EDX, and TEM. Progressive alloying resulted in continuous refinement of the carbide structure, where the crystallite size was reduced to ~11–15 nm and the lattice microstrain increased up to 0.93 % after 20 h of MA. TEM observations confirmed the formation of highly dispersed nanocrystalline Ti_0.8V_0.2C solid-solution carbide particles with sizes of 15–20 nm. This work demonstrates the effectiveness of MA in generating a novel Ti–V-based nanocarbide solid solution and highlights the critical role of milling duration in tailoring structural refinement and defect accumulation at the nanoscale. Full article

In this work, gradient-sized Pr₆O₁₁ powders were fabricated via a wet ball-milling method with variable milling durations. The microstructural evolution and temperature-dependent magnetic properties of different Pr₆O₁₁ powders were systematically investigated. The results reveal that wet ball-milling effectively refines powder particle size and introduces controllable lattice defects without altering the intrinsic crystal structure. Magnetic measurements over a temperature range of 3–300 K demonstrate that the unmilled powder exhibits typical paramagnetic behavior. However, milling-induced particle refinement significantly enhances the low-temperature magnetic moments of Pr₆O₁₁, accompanied by characteristic superparamagnetic hysteresis at 3 K. Furthermore, the fitted paramagnetic Curie temperature $\theta p$ and Curie constant C confirm that the magnetic regulation is milling-affected and dependent on milling time. Prolonged milling above 1 day cannot continuously increase low-temperature magnetic moments. The above temperature-dependent magnetic properties of milled Pr₆O₁₁ can possibly be attributed to milling-induced grain refinement and lattice distortion, as supported by the microstructure analysis. This work provides valuable physical insights into the low-temperature magnetic properties of Pr₆O₁₁ and offers guidance for its magnetic functional applications. Full article

Resilience assessment in production systems requires metrics that capture not only the magnitude of performance loss but also the dynamic characteristics of recovery. This paper proposes a quantitative resilience indicator, ρ, based on the vector representation of availability time series. This paper tests the hypothesis that geometric vector encoding of availability data provides a more discriminating resilience assessment than scalar aggregate metrics by capturing recovery trajectory characteristics not reflected in mean availability alone. The methodology transforms discrete availability data into geometric vectors, from which disturbance events are encoded as triangles whose properties quantify resilience loss. The indicator combines a normalized area ratio—capturing the depth and duration of the availability drop—with an Angle Factor that penalizes incomplete or slow recoveries through the inclination of a closure vector. The resilience indicator, ρ, is a damage-based metric in which lower values denote better resilience and higher values indicate greater resilience loss. The global resilience of an asset is derived as the arithmetic mean of individual event coefficients, enabling longitudinal benchmarking. The proposal is validated through a case study applied to the ball milling circuit of a sulfide copper concentrator, comparing alternative topological configurations. Results demonstrate that configurations with similar mean availability exhibit distinct resilience profiles. The proposed indicator supports data-driven decision-making in asset management and maintenance strategy design. Full article

Urushiol, the main active compound in raw lacquer, is a catechol derivative with long alkyl side chains. Its use in traditional coatings has long been held back by slow enzymatic curing, UV sensitivity, and its own allergenicity. Over the past decade, greener ways to extract it have emerged—ultrasound- and microwave-assisted methods, plus vortex-assisted matrix solid-phase dispersion and ball-milling-enhanced microextraction. These approaches have been shown to recover urushiol efficiently, using less solvent and lowering operator risk. The catechol structure explains its many uses: fast-curing UV coatings that resist corrosion, antibacterial materials (both plain and metal-coordinated), superwetting surfaces for oil–water separation, and selective uptake of heavy metals and rare-earth ions. Early biomedical work also hints at its potential as a bioactive scaffold, drug carrier, or low-toxicity starting point. To balance performance and safety, multiple strategies have been proposed to reduce allergenicity: protecting the hydroxyl groups, modifying specific sites on the ring, and designing synthetic mimics. Still, a few bottlenecks are holding back industrial scale-up. These include large-scale green extraction, long-term material stability, and the lack of solid biocompatibility data. Future work needs to integrate three core research directions: high-throughput structure–activity–toxicity screening, cross-disciplinary molecular design, and life-cycle assessment. The integrated development of these three directions will facilitate the industrial transformation of urushiol-based materials from laboratory prototypes to high-value commercial products. This review summarizes and outlines a roadmap for green extraction, functional polymer applications, and the safe use of urushiol. Full article

The valorization of agricultural residues and post-consumer plastics is critical for achieving a circular economy. This study presents a sustainable pathway to fabricate eco-friendly acoustic panels by melt-blending recycled high-density polyethylene (rHDPE) with 10–50 wt% rice straw waste-derived nanofillers. Multi-stage chemical refinement (10% NaOH mercerization and H₂O₂ bleaching) before ball milling isolated nanofibrils under 50 nm. XRD analysis showed a crystallinity index increase from 37.0% (untreated) to 67.2% (bleached), confirming amorphous phase removal. FTIR and SEM verified successful delignification and excellent interfacial wetting. Consequently, the 50 wt% bleached cellulose composite exhibited the highest reinforcement, increasing flexural strength by 126% and flexural modulus by 132.6% over neat rHDPE. The hydrophilic framework enhanced environmental biodegradability, yielding a 15.18% maximum weight loss after a 90-day soil burial test, providing a viable end-of-life alternative to persistent synthetics. To optimize acoustic utility, a 1.76% geometric micro-perforation ratio was engineered into the panels. Backed by a 6 cm air cavity, the 50 wt% untreated composite achieved an outstanding peak sound absorption coefficient of 0.98 at a low frequency of 400 Hz. These findings establish these high-filler bio-nanocomposites as high-performance, low-carbon alternatives for noise control in construction and automotive infrastructure. Full article

A one-pot ball-milling chelation method was used to create Cd(II) and Zn(II) complexes of a 3-hydroxy-2-naphthoyl Schiff base derivative (H₂L), which provided greater efficiency under milder reaction conditions. ¹H NMR, ¹³C NMR, UV–Vis, IR, SEM, XRD, EDX, and elemental studies were used to characterize the isolated solid chelates. The optimized structures were confirmed by DFT theoretical calculations, which also yielded important energetic characteristics such as EHOMO and ELUMO. The three-dimensional crystal structures of HePG-2 (PDB ID: 5EQG), MCF-7 (PDB ID: 6NM0), and HeLa (PDB ID: 5IAE) were carefully analyzed after molecular docking experiments were carried out on the formed complexes utilizing Schrödinger’s LigPrep procedure with default parameters. Finally, the antibacterial, antioxidant, DNA-binding, and cytotoxic properties of the tested solid compounds were assessed. Full article

This article systematically reviews the structural characteristics of layered double hydroxides and biochar (LDHs/biochar) composites, summarizes the features and optimization strategies of preparation methods such as coprecipitation, hydrothermal synthesis, ball milling, and calcination–reconstruction, analyzes their adsorption performance and mechanisms in controlling various water pollutants including organic contaminants, heavy metals, and nutrients, and provides insights into future research trends and practical applications, aiming to offer references for improving material performance and promoting practical use. The existing research results show that LDHs/biochar composites exhibit good application potential for various pollutants, such as dyes, antibiotics, heavy metal ions, and phosphates. The coprecipitation method is simple and easy to operate, and the LDHs/biochar composites prepared by this method exhibit favorable adsorption performance, with potential for industrial-scale production. The mechanisms of pollutant removal by LDHs/biochar composites primarily include electrostatic attraction, ion exchange, hydrogen bonding, complexation, and π–π electron interactions. Both the biomass type and the LDH type influence the adsorption performance of the composites. Therefore, designing LDHs/biochar composites based on pollutant characteristics and adsorption mechanisms is key to achieving effective pollution control. Currently, research on target pollutant-oriented material design and material regeneration remains underdeveloped and requires further breakthroughs. Full article

With the rapid development of communication technologies, electromagnetic pollution has become increasingly serious, driving the urgent demand for high-performance low-frequency microwave absorbers. This work focuses on Nd-Fe-C powders prepared by high-energy ball milling, aiming to explore low-cost, mass-producible absorbing materials with excellent low-frequency microwave absorption performance. The Nd_10.2Fe_84.6C_5.2 alloy was synthesized via arc melting, and its powders were subsequently fabricated by high-energy ball milling for different milling durations. X-ray diffraction, scanning electron microscopy, and vector network analysis were employed to investigate the effect of high-energy ball milling on the microwave absorption properties of the Nd_10.2Fe_84.6C_5.2 alloy. As the ball milling time increased, the particle size decreased, and the minimum reflection loss shifted to a lower frequency. Additionally, increasing the thickness of the absorbing coating also moved the minimum reflection loss toward the low-frequency region. The Nd_10.2Fe_84.6C_5.2 alloy after 12 h of ball milling had good performance in the C (4.0–8.0 GHz) band when the coating thickness was in the range from 1.4 to 2.2 mm. A minimum reflection loss of −19.2 dB was achieved at 5.2 GHz, and the effective absorption bandwidth (RL < −10 dB, corresponding to a microwave absorption efficiency of 90%) reached 1.8 GHz at a matching thickness of 2.2 mm. Full article

Hot Consolidation (HC) was employed to prepare high-performance aluminum matrix composites reinforced with mechanically alloyed powders. Two different reinforcements, Al₆₅Cu₂₀Nb₁₅ and Al₆₅Co₂₀Nb₁₅, synthesized by high-energy ball milling, were incorporated into an Al₉₅(AlSi)₅ matrix at 20 wt% after homogenization in a Turbula WAB mixer for 2 h. Microstructural characterization using laser granulometry, scanning electron microscopy, and X-ray diffraction confirmed significant particle refinement and the formation of stable intermetallic phases during milling. The Al₆₅Cu₂₀Nb₁₅ system showed the formation of Al₂Cu and Nb-containing intermetallic compounds, while the Al₆₅Co₂₀Nb₁₅ reinforcement phases such as Al₃Nb, AlNb₂, and Al₁₃Co₄ were identified. The consolidated composite exhibited high densification levels, reaching relative densities of 99.6% and 96.77% for composite 1 and composite 2, respectively. In addition, the Vickers hardness increased significantly compared with the unreinforced aluminum matrix, attaining values of 96.34 HV and 68.28 HV for composite 1 and composite 2, corresponding to hardness improvement of approximately 182% and 100%, respectively. The superior densification and hardness of composite 1 were attributed to enhanced interfacial bonding, refined microstructure, and the effective strengthening effect of reinforcement phases. These results demonstrate that the combined use of high-energy mechanical alloying and Hot Consolidation proved to be an efficient approach for producing lightweight aluminum matrix composites with improved microstructural and mechanical properties suitable for advanced structural applications. Full article