Search Results (8,836)

A comparative study on the effects of mechanical treatment by high-energy ball milling on talc (2:1 layered silicate) and kaolinite (1:1 layer silicate) was performed. Industrial samples of talc and kaolin were characterized by XRF, thermal analysis (DTA and TG), and XRD methods. The XRD analysis evidenced the destruction of the crystalline structures of both talc and kaolinite and accessory minerals in the samples, showing an increase in the amorphous phases and a progressive change to a more disordered structure. It was found that high-energy ball milling resulted in a reduction of 48% of talc at 4 h of grinding, and the reduction increased up to ~80% at 32 h. The mechanical treatment produced a decrease in initial kaolinite content by 25% after 4 h of grinding and a reduction of ~70% after 32 h. It was deduced by this analysis that the structure of kaolinite is more difficult to destroy by high-energy ball milling than the structure of talc under the same experimental milling conditions. The structural alterations in talc and kaolinite were anisotropic, with crystal degradation along [00l], and there was a progressive loss of long-range order; moreover, the crystal dimensions following the c-axis direction became too small to produce coherent diffraction. A decrease in crystal size (coherent diffraction microdomain) was observed by the mechanical treatment, with an increase in microstrains produced by high-energy ball milling. Thus, the crystal size decreased from 280 to 200 Å in talc (direction perpendicular to 002) and from 250 to 210 Å in kaolinite (direction perpendicular to 001) after 16 h of grinding, with an important reduction in crystal size up to a value of 138 Å but only in the case of kaolinite at 80 h of grinding, with talc completely amorphous to X-rays at the same grinding time. Microstrains followed an inverse evolution compared to the crystal size, with an increase in the values obtained by progressive grinding in both talc and kaolinite. The values of microstrains were found to be of the same order for talc and kaolinite, although they were relatively higher for talc since it is associated with a greater degree of structural alteration than kaolinite. The XRD results showed an inverse correlation between both parameters, with their relative values being higher for talc compared with kaolinite. The present study is of basic interest for further investigations into the effects of high-energy ball milling using talc and kaolin as raw materials with reduced particle size, for instance, in the ceramic and paper industries. Full article

The efficient utilization of industrial waste (containing alkaline compounds, especially Ca-based species) for flue gas desulfurization (FGD) is of great importance for both environmental protection and resource recovery. In this study, paper industry white mud was modified with Ca(OH)₂ to develop a cost-effective sorbent with enhanced SO₂ removal performance. Optimization experiments identified the best preparation conditions as a 1:1 Ca(OH)₂/white mud ratio, 60 °C modification temperature, 6 h reaction time, and a liquid-to-solid ratio of 3:1. Under these conditions, the sorbent achieved nearly 100% SO₂ removal in the first 6 h and maintained >90% efficiency after 10 h, significantly outperforming raw white mud and Ca(OH)₂ alone. Characterization revealed that the superior performance originated from structural stability and abundant active sites. BET analysis showed a high surface area (24.8 m²·g⁻¹) and pore volume (0.160 cm³·g⁻¹), which were largely preserved after desulfurization, indicating resistance to pore blockage. SEM images confirmed a transition from porous aggregates to densified product layers, consistent with a shrinking-core/product-layer mechanism. XRD identified CaSO₄·2H₂O as the dominant product, while in situ FTIR demonstrated that O₂ promotes sulfite oxidation and H₂O accelerates hydrated sulfate formation, enhancing activity but causing faster pore blocking. The presence of NO extended sorbent durability by catalyzing continuous sulfite oxidation through NO/NO₂ redox cycling. Overall, Ca(OH)₂-modified white mud combines high reactivity, durability, and structural stability, offering a promising alternative to conventional sorbents. This work provides a viable route for the resource utilization of paper industry waste and practical insights for designing efficient and sustainable materials for industrial FGD systems. Full article

Hafnium carbide (HfC) ceramics are of growing interest due to their exceptional mechanical properties and ultra-high melting points, making them ideal for extreme environmental applications. In this study, we present a synthesis route for HfC nanoparticles via carbothermal reduction of an organic–inorganic hybrid precursor derived from hafnium tetrachloride (HfCl₄) and pectin, followed by thermal treatment at 1500 °C for 1.5 h under an argon atmosphere. According to TGA/DSC analysis of the hybrid precursor, hafnia phases initially formed during pyrolysis and were subsequently converted into HfC at 1500 °C, with the endothermic carbothermal reduction reaction initiating near 1200 °C. Comprehensive characterization using Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), X-ray diffraction (XRD) with Rietveld refinement, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) confirmed the synthesis of hafnium carbide (HfC) exhibiting predominantly cubic morphology. XRD analysis determined a lattice parameter of a = 4.63 Å and an interplanar spacing of d = 2.68 Å. Rietveld refinement revealed a phase composition of 98.08% HfC and 1.92% monoclinic hafnium dioxide (m-HfO₂). Debye–Scherrer analysis indicated an average crystallite size of 67.6 nm. SEM and TEM images showed uniformly distributed nanoparticles with an average particle size of approximately 65–70 nm. Full article

Metal–organic frameworks (MOFs) are unique microporous materials being explored for a wide range of applications. Their porosity and high surface areas can readily be exploited for guest–host interactions, separations, and photochemical catalysis, but many suffer from poor charge separation and fast electron–hole recombination. Introducing structural defects, such as missing linkers or metal nodes, can create unsaturated metal sites and alter band structure, conductivity, and light absorption, improving photocatalytic performance. UiO-66-NH₂ and MIL-125-NH₂ are water-stable, visible-light-absorbing MOFs well suited for photocatalytic degradation of organic dyes. In this work, the influence of defect engineering on photocatalytic properties of MOFs was investigated using formic and acetic acid modulators with UiO-66-NH₂ and variable temperature with MIL-125-NH₂ during synthesis. The resulting materials were characterized by XRD, FTIR and SEM/EDS. Defect states were tracked using N₂ adsorption/BET analysis and UV–Vis spectroscopy. Photocatalytic activity was evaluated by monitoring Rhodamine B (RhB) degradation in aqueous solution under simulated solar irradiation. It was found that increased temperature beyond 120 °C during synthesis promotes mesopore formation and decreases the bandgap in MIL-125-NH₂, resulting in a more photoactive material. Defective MIL-125-NH₂ synthesized at 150 °C showed the most defects and proved to be the best photocatalyst investigated in this study. Formic acid modulation in UiO-66-NH₂ generated smaller crystallites that slightly increased the bandgap; however, the surface area decreased proportionally with the amount of formic acid used. The decreased surface area and observed enhancement in photocatalytic degradation of RhB suggest that formic acid introduces defects into the UiO-66-NH₂ framework that enhance photocatalytic properties. UiO-66-NH₂ treated with acetic acid resulted in larger crystals, increased bandgaps, and increased surface areas, suggesting that acetic acid simply modulates growth rather than imparting defects to the framework. Full article

In this work, iron–phosphorus-based composite biochar (FPBC) was prepared by modification with the leachate of spent LiFePO₄ batteries. The effects of solution pH, dosage, adsorption time, initial concentration, and temperature on the adsorption performance of FPBC were investigated by batch adsorption experiments with Pb(II) and Sb(III) as the target pollutants, and the adsorption mechanism was explored using SEM, BET, XPS, FTIR and XRD characterization. The results indicated that as the initial pH of the solution increased, the removal efficiency of FPBC for Pb(II) gradually increased, while the removal efficiency for Sb(III) remained largely unchanged. The removal of Pb(II) and Sb(III) by FPBC fitted the pseudo-second-order kinetic model and the three-step intraparticle diffusion model, indicating that their removal was primarily controlled by chemical adsorption. Isothermal adsorption studies revealed that FPBC adsorption of Pb(II) better fitted the Langmuir and D-R models, suggesting a monolayer-dominated adsorption process. In contrast, adsorption of Sb(III) fitted the Langmuir, Freundlich, and Temkin models, suggesting a combination of monolayer and multilayer adsorption characteristics. The maximum adsorption capacities of FPBC for Pb(II) and Sb(III) were 312.54 mg·g⁻¹ and 219.20 mg·g⁻¹ at 30 °C, which were approximately 12.85 and 3.37 times those of commercial corn stalk biochar (BC). Thermodynamic analysis confirmed that the removal of Pb(II) and Sb(III) by FPBC was a spontaneous and endothermic process. In addition, FPBC demonstrated strong selective adsorption of Pb(II) in the binary co-adsorption system of Pb(II) and Sb(III). Mechanism studies indicated that Pb(II) removal primarily occurred through co-precipitation, complexation, ion exchange, and electrostatic adsorption, while Sb(III) was mainly adsorbed by FPBC via redox reactions and complexation. Therefore, this work not only provides a low-cost, high-performance adsorbent for the remediation of water contaminated with Pb(II) and Sb(III), but also opens up new avenues for the resource recovery of the leachate of spent LiFePO₄ batteries. Full article

This study investigates the synthesis of 1-hydroperoxyadamantane, addressing discrepancies in the prior literature. Our results demonstrate that previous authors were unable to obtain the claimed compound under the conditions they described. We confirmed that 1-hydroperoxyadamantane can be synthesized in good yields via the reaction of 1,3-dehydroadamantane with concentrated hydrogen peroxide in DCM. Structure of 1-hydroperoxyadamantane was confirmed by SC XRD analysis. These findings clarify the conditions necessary for successful synthesis of this compound and highlight the importance of comprehensive analytical verification. This study also provides a very detailed, repeatedly verified method for synthesizing 1,3-dehydroadamantane and a description of the necessary laboratory equipment. Full article

Cellulose nanofiber (CNF)–boron nitride nanotube (BNNT) composite separators have been widely investigated; however, many demonstrations rely on BNNT pretreatment or multistep processing to secure dispersion and integration. HwBKP-derived CNF separators (HCNF), based on an enzymatically pretreated and turbulence-flow nanomill processed CNF suspension, were combined with BNNTs without pretreatment to fabricate BNNT-incorporated composite membranes (HBNT-05 and HBNT-10) via a simple stirring–filtration–drying route. The CNF suspension and membranes were characterized by fibril image analysis, SEM, AFM, FTIR, and XRD, together with wettability and surface free-energy measurements, to examine BNNT-loading-dependent changes in separator structure and surface microtexture. When evaluated in NCM811||Li half-cells, the BNNT-incorporated membranes exhibited composition-dependent electrochemical performance trends relative to the BNNT-free CNF membrane, while the commercial polyolefin reference remained favorable at the highest tested C-rate. These results suggest that the present fabrication route enables effective BNNT incorporation without BNNT pretreatment under the studied conditions, providing a practical strategy to tune biomass-derived CNF membranes for energy-storage applications. Full article

Supersulfated cement (SSC) is an environmentally friendly cementitious material with a low clinker content, in which industrial byproduct gypsum serves as the sulfate source, thereby enabling the valorization of solid waste. The hydration process, pore structure, microstructure, and hydration products were investigated using paste samples by means of isothermal calorimetry, X-ray diffraction (XRD), thermogravimetric analysis (TG–DTG), Fourier transform–infrared spectroscopy (FT-IR), mercury intrusion porosimetry (MIP), and scanning electron microscopy (SEM), while compressive strength was evaluated using mortar specimens. Compared with ordinary Portland cement (OPC), SSC offers clear advantages in reducing energy consumption and greenhouse gas emissions. In this study, the effects of titanium gypsum (TG) and flue gas desulfurization gypsum (FGD) on the hydration behavior, fluidity, mechanical properties, and microstructural evolution of an anhydrite (AH)–phosphogypsum (PG)-based SSC were systematically investigated. The results indicate that the incorporation of 11% TG and FGD mitigates the strong sulfate environment caused by the rapid dissolution of soluble AH, thereby regulating the hydration process. As the proportion of TG and FGD increased, the cumulative heat release within 72 h gradually decreased. When AH was completely replaced, the cumulative heat release of TG4 and FG4 decreased by approximately 19.7% and 28.6%, respectively. TG and FGD exhibited opposite effects on the fluidity of SSC while both promoting strength development. Among all mixtures, TG2 and FG2 showed the best performance, with the highest 28-day compressive strengths of 50.15 MPa and 51.95 MPa, respectively. Microstructural analysis reveals that differences in particle size distribution and dissolution kinetics among gypsums governed the sulfate release characteristics and slag activation mechanisms, thus leading to distinct hydration pathways, pore structure evolution, and microstructural densification. This study provides a theoretical basis for the efficient utilization of various industrial byproduct gypsums and offers important guidance for the controllable design of SSC performance. Full article

This study quantitatively evaluates the effect of solid-phase pre-reduction of chromite concentrate on the energy efficiency and techno-economic performance of high-carbon ferrochrome (HC FeCr) smelting. Laboratory pre-reduction experiments were conducted at 1200–1400 °C using Shubarkol coal, metallurgical coke, and special coke as carbonaceous reducing agents. Structural and phase transformations were characterized by X-ray diffraction (XRD) and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). At 1200 °C, the degree of metallization remained low (<5%), whereas at 1400 °C it increased to 41.3% under laboratory conditions and up to 65% in pilot-scale tests due to the decomposition of the spinel matrix and the formation of metallic and carbide phases. The application of pre-reduced feedstock in a submerged arc furnace reduced specific electricity consumption by up to 33.5% compared with conventional smelting and increased chromium recovery to 89.71%. Industrial-scale extrapolation indicates the potential to decrease power consumption to approximately 3190 kWh/t of alloy. Techno-economic analysis demonstrates that the use of pre-reduced feedstock reduces the production cost by approximately 10–23%, depending on the type of carbonaceous reducing agent (Shubarkol coal, metallurgical coke, or special coke). Special coke provided the highest energy efficiency, whereas Shubarkol coal ensured the greatest direct economic benefit. The integrated microstructural, energetic, and economic assessment confirms the industrial applicability of the proposed pre-reduction approach. Full article

Cr-based composite coatings with superior wear resistance are in growing demand for high-performance applications in the automotive, aerospace, and general manufacturing sectors. In this study, an Al10Cu alloy produced via powder metallurgy was coated with a chromium/nanodiamond (Cr/ND) composite layer using an electrodeposition process to enhance its tribological performance. The coatings were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. The resulting Cr/ND layer exhibited a uniform thickness of 73.5–76.2 μm and markedly improved surface hardness (809.4 HV), representing a 15-fold increase over the uncoated alloy (53.6 HV). Pin-on-disk tribological testing under dry sliding conditions showed complete elimination of detectable mass loss (0.00 mg vs. 0.55 mg for uncoated) within the measurement system resolution, indicating excellent resistance to both abrasive and adhesive wear. XRD analysis revealed the formation of a hexagonal close-packed Cr₂H phase with incorporated nanodiamond particles. To capture and predict the temporal evolution of the friction coefficient, a customized dual-layer long short-term memory neural network—optimized with a look-back window of 3 timesteps and ReLU-activated dense layers—was implemented. The model achieved superior predictive performance on the coated system, with validation and test R² values of 0.9973 and 0.9965, respectively, demonstrating enhanced modeling accuracy for surface-engineered materials. These findings demonstrate a significant advancement in wear protection for aluminum alloys and introduce a robust data-driven approach for real-time friction prediction in engineered surfaces. Full article

In this work, Filipendula ulmaria (L.) Maxim, a perennial herbaceous plant from the Rosaceae family, was considered a novel source of obtaining rutin for pharmaceutical purposes. Rutin was extracted from the plant parts collected in the flowering summer period and dried at 40 ± 3 °C. The process was carried out using the ethanol extraction and fractionation of extracted compounds, and it yields the 95 wt% purity crystalline product. The phase composition of the extracted rutin was verified by the XRD analysis and NMR measurements. It was found that 2.85% of rutin could be extracted from Filipendula ulmaria, which is 1.2 times higher than the results of similar studies. The biological activity of the isolated rutin was tested on rats. It was established in vivo that the extracted rutin normalizes blood glucose levels (glucose and glycosylated hemoglobin), insulin resistance (HOMA-IR index) and reduces the severity of dystrophic changes in the liver caused by high-fat and high-carbohydrate diets. The introduction of rutin corrects lipid profile indicators (triglycerides, cholesterol, cholesterol fractions in lipoproteins and atherogenic indices), cytolysis indicators of hepatocytes, and liver steatosis (ALT, AST/ALT, triglycerides). Thus, the novel source of rutin opens the possibility for a wide use of this flavonoid in the food technology and pharmaceutical industry. Full article

Composite materials are commonly employed because of their superior mechanical and electrical properties, as well as their lower density compared to metals. In this research, ceramic waste from the Casablanca region (Morocco) was incorporated into a composite material by combining it with finely ground ceramic fragments (CB) in an unsaturated polymer (UP) resin. The study objectives include the characterization of ceramic waste, evaluation of the mechanical stiffness, influenced by CB content and specimen thickness, and the assessment of its hydric behavior and erosion resistance in aggressive chemical environments. This valorization approach includes a baseline assessment of unmodified ceramic waste and UP’s compatibility and systematic documentation of geometry-dependent stiffness in short-cylinder compression tests. Several methods were used to characterize the material, including XRD, optical microscopy, FTIR-ATR, erosion testing, hydric behavior analysis, surface area measurement, and Young’s modulus. The results showed increased tensile strength and stiffness compared to the starting materials through the evolution of Young’s modulus, demonstrating the enhanced mechanical quality of the composite. Additionally, the material properties changed with the CB content and thickness of the sample, which indicated the potential for optimization. These findings advocate for the reuse of Moroccan industrial ceramic waste as a viable mineral filler for semi-structural polymer composites, supporting the circular economy, environmental sustainability, and public health. Full article

Objective: The objective is to investigate and optimize the β-cyclodextrin inclusion process for volatile oils in Ligusticum Chuanxiong–Vinegar cyperus rotundus based on Quality by Design (QbD) principles. Methods: First, ligustilide and α-cyperone were selected as inclusion process indicator components using high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS). Single-factor experiments were conducted to preselect the inclusion speed based on ligustilide and α-cyperone content as evaluation criteria. Subsequently, using the inclusion rates of ligustilide and α-cyperone as evaluation criteria, a factorial design was employed to investigate the inclusion temperature, inclusion time, and the volume ratio of β-cyclodextrin solution to essential oil, thereby optimizing the inclusion process parameters. Finally, the inclusion process parameters were validated, and the inclusion rates were determined. The obtained inclusion complexes were characterized by microscopic analysis, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), and differential scanning calorimetry (DSC). Furthermore, phase dissolution studies and molecular docking were employed for confirmation. Results: The optimal process parameters were determined as follows: encapsulation speed of 300 rpm, β-cyclodextrin solution excess of 6, encapsulation time of 2.5~3 h, and encapsulation temperature of 30~35 °C. The encapsulation rates for ligustilide and α-cyperone in the resulting inclusion complex were 63.15~64.74% and 71.33~76.89%, respectively. Structural characterization confirmed the formation of the inclusion complex. Conclusions: This inclusion process is reliable and provides a reference for preparing β-cyclodextrin inclusion complexes of volatile oils in formulations containing the Chuanxiong–Vinegar cyperus rotundus drug pair. Full article

In this study, the in situ solvothermal synthesis of a copper-based metal–organic framework (Cu-BTC MOF) into two porous ceramic substrates with a 10 cm diameter and 2 cm thickness was reported. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, diffuse reflectance spectroscopy (DRS), Tauc plot analysis, optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were the techniques that were utilized to verify the formation and incorporation of the MOF into ceramics (two samples, with different SiO₂ particles; 500 µm (Ceramic 1), and 150 µm (Ceramic 2)). The synthesized Cu-MOF exhibited a crystalline structure. Both the composites and the Cu-MOF exhibited visible-light absorption, with optical band gaps of 2.5 eV and 2.4 eV, respectively, as determined by DRS. TEM images demonstrated that crystalline MOF domains were successfully included inside the ceramics. Methyl orange (MO), Congo red (CR), and methylene blue (MB) were used to assess the composites’ ability to remove dyes. Catalytic hydrogenation, powered by in situ hydrogen production from NaBH₄ hydrolysis, demonstrated high removal efficiencies of 91–97% after 60 min. Adsorption, on the other hand, was ineffective. Despite undergoing four consecutive cycles without performance degradation, the materials demonstrated remarkable recyclability. Cu-MOF@ceramic composites are effective, durable, and practically applicable for improved wastewater treatment. Full article

Conventional admixture-based self-healing technologies are often limited by inadequate internal water supply and a scarcity of unhydrated gel particles. Therefore, this study proposes a new self-healing method that leverages the synergistic interplay between the chemical repair of sodium silicate and the physical clogging of superabsorbent polymers (SAPs) to overcome the aforementioned limitations. The healing efficiency of cement mortar was assessed through compressive strength recovery, capillary water absorption, and ultrasonic pulse velocity (UPV). Microstructural evolution and healing mechanisms were elucidated using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Results indicate that at an optimal dosage (0.5 wt.% for both admixtures), the healing performance is significantly enhanced: the compressive strength recovery rate reaches 103.1%, the capillary water absorption coefficient decreases by 16.57 × 10⁻³, and the UPV recovery achieves 95.4%. Microstructural analysis reveals that sodium silicate facilitates the reaction between ${\mathrm{Ca}}^{2+}$ and ${\mathrm{S}\mathrm{i}\mathrm{O}}_3^{2-}$ ions, leading to the in situ precipitation of dense C-S-H gel at the crack interface, thereby enabling chemical repair. In contrast, SAP contributes to physical sealing via a swelling and release mechanism. Full article