Search Results (7,704)

Branched poly(vinyl alcohol) (PVA) was synthesized via chemical modification of linear PVA with epichlorohydrin in an alkaline aqueous medium under conditions preventing crosslinking. Branching was confirmed by IR and Heteronuclear Single Quantum Coherence (HSQC) spectroscopy, as well as by viscometric analysis. An iterative procedure is proposed for refining the branching factor (g) and the viscosity-average molecular weight of the branched macromolecules. Coil diameters determined by viscometry and dynamic light scattering showed satisfactory agreement. While an increase in the viscosity-average molecular weight of branched PVA enhances its surface activity in the low-adsorption region, the branched geometry itself hinders subsequent adsorption due to steric shielding of the interface. This correlates with wetting behavior on Teflon: lightly branched PVA requires a higher concentration to induce wetting inversion than its linear counterpart but further increase in molecular weight shifts the inversion point to lower concentrations due to a higher density of hydroxyl groups. Concurrently, the concentration dependence of the work of adhesion degenerates with increasing molecular weight. Despite their reduced adsorption capacity, the specific geometry of branched PVA macromolecules provides effective steric stabilization of micrometer-sized particles during styrene suspension polymerization. These results demonstrate that chain branching in PVA is a powerful tool for tuning its adsorption properties, stabilizing ability, and interfacial activity. Full article

Since the first successful synthesis of borophene in 2015, this atomically thin boron allotrope has attracted extensive attention due to its polymorphic structures, metallic conductivity, and outstanding mechanical flexibility. As a new member of the two-dimensional (2D) materials family, borophene exhibits a unique triangular lattice with tunable hexagonal vacancies, leading to rich structural diversity and anisotropic physical properties. Recent breakthroughs in synthesis—particularly molecular beam epitaxy (MBE), chemical vapor deposition (CVD), and solvothermal-assisted liquid-phase exfoliation (S-LPE)—have significantly expanded the accessible structural phases and improved control over film quality and stability. Meanwhile, borophene’s distinctive combination of structural and electronic characteristics has enabled its rapid development in both energy and biomedical applications. In energy storage, borophene serves as a promising anode material for lithium/sodium-ion batteries and a lightweight medium for hydrogen storage and supercapacitors, owing to its metallic conductivity, high surface charge density, and large adsorption capacity. In biomedicine, borophene-based nanoplatforms exhibit excellent photothermal conversion efficiency, enabling multifunctional roles in cancer diagnosis and therapy. Despite these advances, several challenges—such as environmental instability, oxidation susceptibility, and limited scalable synthesis—continue to restrict practical implementation. Future progress will depend on chemical functionalization, surface passivation, and machine-learning-assisted materials design to achieve oxidation-resistant, large-area, and biocompatible borophene derivatives. This review summarizes recent advances in borophene synthesis, structural engineering, and multifunctional applications, while outlining key scientific challenges and future opportunities for the realization of borophene-based materials in next-generation energy and biomedical systems. Full article

This study evaluates β-cyclodextrin (β-CD) and malonic acid functionalized pine sawdust biochar for organic pollutant removal, benchmarking efficacy against commercial Norit GSX activated carbon for sustainable water treatment. Characterization revealed that β-CD modification successfully developed porous structures, with Sawdust Activated Carbon (SDAC) and Norit GSX Activated Carbon (GSXAC) achieving Brunauer–Emmett–Teller (BET) surface areas of 438.36 m²/g and 1223.79 m²/g, respectively. Adsorption kinetics and isotherm studies demonstrated the superiority of β-CD-modified materials over traditional acid-functionalized variants. The adsorption kinetics were exceptionally well-described by the Pseudo-Second-Order model R² > 0.99, indicating that the process is governed by chemical interactions rather than simple physical attachment. In contrast, the Pseudo-First-Order and Elovich models provided poor descriptions of the system (R² = 0.54 and 0.11, respectively). An isotherm analysis further confirmed the heterogeneous nature of the SDAC surface, with the Freundlich model exhibiting an excellent fit (R² > 0.99) and an n value of 0.79. For GSXAC, the Freundlich model also outperformed the Langmuir model, yielding a K_F of 441.72 mg/g and n = 0.77, reflecting high adsorption intensity on a heterogeneous surface. The comparative advantage of β-CD is in line with its unique truncated cone structure, which is consistent with guest–host inclusion complex formation, multi-modal hydrogen bonding, and enhanced pH resilience. These findings validate β-CD-modified sawdust-derived adsorbents as potential, sustainable, high-capacity alternatives to industrial-grade carbons. Full article

Deep coalbed methane (CBM) is a core exploration and development domain for increasing the reserves and production of unconventional natural gas in China. A systematic understanding has been established on the enrichment and accumulation mechanism of high-rank deep CBM in the southern section of the eastern margin of the Ordos Basin. However, the medium-rank deep CBM in the Mugua Area of the Shenfu Gas Field in the northern section of the eastern margin has essential differences from that in the southern section in terms of coal rank and hydrocarbon generation–occurrence mechanism, and its accumulation and enrichment regularity remain unclear. The core innovations of this study are as follows: aiming at the unclear accumulation regularity of medium-rank deep CBM in the northern section of the eastern margin of the Ordos Basin, we first reveal the spatiotemporal synergistic coupling reservoir-controlling mechanism of five factors (sedimentation–thermal evolution–temperature–pressure–preservation), determine the 1750 m critical transition zone of the deep CBM occurrence state, and establish two types of accumulation models adapted to the geological characteristics of medium-rank coal. Taking the No.8+9 coal seams of the Taiyuan Formation in the Mugua Area as the research object, based on the theoretical foundation of the dual properties of coal seams as the “source rock–reservoir”, this paper comprehensively adopted technical means such as core observation, drilling and logging data, and high-pressure isothermal adsorption experiments to carry out systematic multi-dimensional studies on sedimentary microfacies, coal reservoir characteristics, thermal evolution degree, and gas-bearing property; identified the main controlling factors of CBM accumulation; and constructed the accumulation model. The results show the following: ① The main burial depth of the coal seams is more than 1700 m, with a thickness ranging from 7.0 to 21.3 m and an average of 15.1 m, and the coal structure is dominated by the primary structure; maximum vitrinite reflectance (R_o,max) is generally distributed from 0.90% to 1.39% with an average of 1.08%, belonging to typical medium-rank coal; and the organic matter type is mainly Type III, with an average gas content of 10.01 m³/t, where the average proportion of desorbed gas in the total gas content is 83.91%, featuring superior source and reservoir conditions and a good foundation for CBM enrichment. ② The CBM accumulation in this area is jointly controlled by the coupling of four factors: sedimentation, thermal evolution degree, temperature–pressure effect, and preservation conditions. The tidal flat–lagoon facies control the development of high-quality coal seams; regional metamorphism dominates the hydrocarbon generation capacity and gas quality of coal seams; the temperature–pressure coupling forms a critical adsorption zone at 1750 m, defining the differentiation boundary of the occurrence state of deep CBM; and high-quality mudstone cap rocks, a stable structural environment, and closed hydrodynamic conditions constitute the three key guarantees for gas enrichment. ③ Two types of accumulation models are divided: “source–reservoir integration + multi-factor synergistic enrichment type” and “source–reservoir limited + insufficient accumulation condition type”. Among them, the four reservoir-controlling factors of the synergistic enrichment type are highly coupled, with excellent gas-bearing property and strong recoverability. This study systematically clarifies the enrichment and accumulation regularity of medium-rank deep CBM in the Mugua Area and improves the accumulation theory of medium-rank deep CBM in the northern section of the eastern margin of the Ordos Basin. Full article

The uncontrolled discharge of synthetic azo dyes such as methyl orange (MO) into water bodies has become a major environmental concern because of their strong chemical stability, limited biodegradability, and harmful effects on aquatic ecosystems. In this study, MgNiFe layered double hydroxides (LDHs) were synthesized through a co-precipitation route using a molar ratio of (Mg + Ni)/Fe equal to 3, and their adsorption ability toward MO in aqueous media was investigated. The prepared materials were characterized by X-ray diffraction (XRD), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDX), Fourier-transform infrared spectroscopy (FTIR), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The characterization results revealed the successful formation of a hydrotalcite-like layered structure with good crystallinity, a relatively uniform distribution of metallic species, and the incorporation of carbonate anions within the interlayer galleries. In addition, the adsorption performance was evaluated by studying the effects of several operational factors, namely adsorbent dosage, initial pH, and contact time. To better understand the interaction between these parameters and identify the optimum operating conditions, a Box–Behnken response surface design was applied. The results indicate solution pH is the most influential parameter in the adsorption process. Under optimized conditions, a maximum removal efficiency of 86.86% was obtained, corresponding to an adsorption capacity of approximately ~86.86 mg·g⁻¹ (based on 100 mL solution volume). The enhanced adsorption performance may be attributed to the combined effect of the multivalent metal cations (Mg²⁺, Ni²⁺, and Fe³⁺), likely increases the surface positive charge density of the LDH and promotes interactions with anionic dye molecules. These interactions are suggested to involve electrostatic attraction and possible surface adsorption processes. However, in the absence of post-adsorption characterization, the exact adsorption mechanism remains hypothetical. Overall, the results demonstrate the promising potential of MgNiFe LDHs as efficient adsorbent materials for the treatment of dye-contaminated wastewater. Full article

Sustainable management of industrial solid waste is critical for a circular economy. This study presents a novel approach for valorizing blast furnace slag (BFS) into NaA zeolite through selective acetic acid leaching followed by hydrothermal crystallization. The leaching step selectively extracts Ca²⁺ and Mg²⁺ while efficiently retaining silicon and aluminum in the solid residue, producing a reactive aluminosilicate precursor that facilitates zeolite nucleation and growth. The effects of the silicon-to-aluminum molar ratio (n(Si)/n(Al)), crystallization temperature, and duration on the phase evolution and morphology were systematically investigated. The results demonstrate that phase-pure NaA zeolite with high crystallinity and a uniform cubic morphology can be obtained from precursor gels with n(Si)/n(Al) ratios of 0.5–1.25. Optimal synthesis conditions were identified as n(Na):n(Si):n(Al):n(H₂O) = 6:1:1:240 at 373 K for 8 h. The resulting zeolites exhibit a BET specific surface area of 52.1 m²/g, a micropore volume of 0.016 cm³/g, an average adsorption pore size of 4.7 nm, and an external specific surface area of 12.8 m²/g. It achieved near-complete removal of Cu²⁺ and high adsorption efficiencies for Pb²⁺ (77.78%) and Ni²⁺ (71.79%) from 250 mg/L solutions at 298 K with a dosage of 4.0 g/L, following the affinity sequence Cu²⁺ > Pb²⁺ > Ni²⁺, with all pairwise differences statistically significant at p < 0.001, using one-way ANOVA and Tukey’s HSD tests. The adsorption of three metal ions was most accurately described by the Freundlich isotherm and pseudo-second-order kinetic models, indicating heterogeneous multilayer chemisorption. The theoretical maximum monolayer adsorption capacities (q_max) were 307.67 mg/g for Cu²⁺, 246.09 mg/g for Pb²⁺, and 173.79 mg/g for Ni²⁺, whereas the kinetic equilibrium adsorption capacities (q_e) reached 62.69, 48.85 and 41.69 mg/g, respectively. This study demonstrates a value-added strategy for valorizing BFS into a micro-mesoporous adsorbent, advancing both circular resource utilization and environmental remediation. Full article

The hydrogen evolution reaction (HER) of hydrogen production by water electrolysis under alkaline conditions faces enormous challenges, namely, high catalyst overpotential and reliance on noble metal catalysts. As a transition metal, Ni has the advantages of low cost and excellent HER performance. This study aims to develop high-activity and low-cost HER catalysts to replace noble metal catalysts. In this work, a composite structured HER catalyst based on Ni and hybridized with Ni(OH)₂ and NiO was prepared by multi-field coupled electrodeposition. Under the reversible hydrogen electrode (RHE), low overpotentials of 248 mV and 341 mV were achieved at current densities of 500 mA·cm⁻² and 1000 mA·cm⁻², respectively, making it more suitable for industrial high-current-density water electrolysis for hydrogen production. Moreover, the catalyst achieves long-term stable operation at a high current density of 1000 mA⋅cm⁻² in industrial-grade ALK water electrolysis, with highly stable microstructure and chemical composition before and after the durability test. Theoretical calculations show that compared with the NiM catalyst, Ni@NiM enhances the adsorption capacity for water molecules, further optimizes the ion transport of the catalyst, and the complementarity and synergy in the electronic structure among these multiple components significantly improve the HER activity of the catalyst. Full article

At present, human activity is the main source of water pollution. The tanning industry is a primary source of water contamination with Cr(III), which can cause various diseases if ingested. A circular economy approach proposes an effective, low-cost solution. The utilization of waste from the food industry is used for the removal of Cr(III) through biosorption. This study evaluated the adsorption capacity of orange peel (OP) and pineapple crown (PC) pretreated with H₂O₂ and NaOH was evaluated under different operating conditions. The physicochemical properties of the biosorbents were characterized using techniques such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results show that treatment with NaOH at 60 °C obtained an adsorption capacity of 61.63 mg/g and 64.19 mg/g for OP and PC, respectively. The combined biosorbents resulted in an approximately 50% increase in the adsorption capacity of Cr(III) compared to individual biosorbents. The isotherms that best fit the experimental data were Sips and Redlich–Peterson (RP) models, suggesting heterogeneous adsorption behavior in biosorbents. Thermodynamic parameters indicated that biosorption process was spontaneous and endothermic. Full article

This study presents the synthesis and use of a novel bamboo-derived magnetic activated carbon (BMAC) for the effective removal of cationic and anionic dyes, specifically methylene blue (MB), methyl orange (MO), and sunset yellow (SY), from aqueous solutions. The adsorbent was synthesized using thermal carbonization and subsequent inclusion of magnetic oxide, yielding a porous structure with improved adsorption and magnetic separation properties. Thorough characterization utilizing SEM, EDX, BET, FTIR, XRD, and TGA/DTA validated the creation of a highly porous material including uniformly dispersed magnetic particles and several surface functional groups. Batch adsorption tests were performed to examine the influences of contact time, adsorbent dosage, initial dye concentration, pH, and temperature. The findings indicated rapid adsorption kinetics, with equilibrium reached in around 60–70 min, and adsorption capacity ranked as MB > MO > SY. Augmenting adsorbent dosage enhanced removal efficiency but diminished adsorption capacity per unit mass due to site unsaturation. The maximum adsorption capacities (q_m) of BMAC were 58.9, 56.3, and 32.7 mg/g for MB, MO, and SY, respectively, as determined from the Langmuir isotherm model, indicating superior performance compared with other reported magnetic activated carbon. The adsorption process was determined to be exothermic and spontaneous, as evidenced by thermodynamic characteristics. The equilibrium data were optimally characterized by the Langmuir isotherm model, indicating monolayer adsorption, whereas the kinetic studies conformed to the pseudo-second-order model, signifying that chemisorption is predominant. The adsorption mechanism encompasses electrostatic interactions, π–π stacking, hydrogen bonding, van der Waals forces, pore filling, and surface complexation with magnetic oxides. The findings indicate that BMAC is an efficient, sustainable, and magnetically recoverable adsorbent for the elimination of both cationic and anionic dyes from wastewater. Full article

Tetracycline (TC) contamination in reservoirs poses environmental and human health risks, particularly antibiotic resistance in ecosystems. Bagasse fly ash (BFA), a by-product from the sugarcane processing industry, has gained attention as an environmentally friendly adsorbent. In this study, we aimed to investigate the mechanism of TC adsorption using batch experiments to evaluate the effects of various factors. For example, pH value ranged from 4 to 10, contact time varied between 0 and 90 min, adsorbent doses were noted as 0.5–2.5 g per 50 mL, the initial concentrations of TC were 10–40 mg/L, and the temperature ranged from 293.15 to 318.15 K. To perform surface characterization of BFA, we employed the scanning electron microscopy (SEM) technique. Based on the results of Fourier transform infrared spectroscopy (FTIR) and surface area analysis (Brunauer–Emmett–Teller; BET), its structure and chemical properties are favorable for TC adsorption. Our results demonstrate that the optimal conditions for adsorption were at pH 7.0 and 60 min contact time. The adsorption capacity tended to increase with the initial concentrations of TC and reached a maximum of 0.58 mg/g when the initial concentration was 40 mg/L. Our kinetic analysis results demonstrate that the pseudo-second-order model exhibited the best fit with the experimental data (R² = 0.95638); in comparison, the results of the isotherm behavior study using the Temkin model (R² = 0.97338) indicated the complex adsorption pathway on the BFA surface. Full article

A major challenge in wastewater treatment lies in developing cost-effective and sustainable adsorbent materials for efficient dye removal. In this study, a novel biochar functionalized with MgO nanoparticles derived from palm leaf waste (MgO/PLB nanoparticles) was synthesized and evaluated for the removal of Congo red (CR) from aqueous solutions. FTIR, SEM, BET, and TGA investigations were used to thoroughly analyze the produced nanocomposite’s physicochemical properties. FTIR analysis verified the successful incorporation of MgO nanoparticles, as evidenced by the presence of characteristic Mg–O vibrations and noticeable changes in surface functional groups. SEM analysis revealed a transformation from a compact structure to a rough, particle-decorated morphology, indicating increased surface heterogeneity. BET analysis indicated the development of mesoporous structures, accompanied by a substantial increase in specific surface area from 2 to 178 m²/g. TGA results further confirmed enhanced thermal stability, indicating the formation of a structurally robust adsorbent. Batch adsorption tests showed that CR removal depends on pH, dosage, concentration, and contact time, with maximum efficiency (~99%) achieved at pH 4 using 0.03 g of adsorbent. The adsorption followed pseudo second order kinetics and was best described by the Langmuir isotherm, with a maximum capacity of 23.4 mg/g. The regenerated nanomaterial retained more than 89% of its adsorption capacity after four successive cycles, demonstrating good reusability and stability. The developed MgO/PLB nanoparticles exhibit efficient adsorption performance, combined with low-cost synthesis and the utilization of abundant agricultural waste, making it an affordable and long-lasting adsorbent for applications involving wastewater treatment. Full article

Severe foaming and a significant decrease in desulfurization performance were noted in a novel UDS solvent applied in a natural gas field in western Sichuan, China. The effects of hydrocarbon and ionic impurities on foaming behavior and the purification performance of candidate adsorbents were investigated. An extraction-gas chromatography method was established and validated for determining total hydrocarbons in amine solutions, enabling quantitative evaluation of hydrocarbon contamination. Controlled contamination experiments revealed that hydrocarbons had the strongest effect on foaming, while sulfate and chloride strongly promoted foam formation; organic acid anions showed only minor effects. Fixed-bed screening identified A-98FM anion-exchange resin as the most effective for anionic impurity removal and AC-02 activated carbon as the best candidate for hydrocarbon purification, with a cumulative adsorption capacity q_0–12 of 14.86 mg/g over 12 h. Pore-structure and thermal-release analyses suggested that conventional pore descriptors alone could not fully explain the dynamic purification performance, while hydrocarbon-related loadings in spent AC-02 occupied accessible pore space and contributed to performance decay. Treatment of a field-aged UDS lean solvent further showed that reductions in target impurities were accompanied by lower foam height and shorter defoaming time. This work provides experimental support for impurity monitoring, foaming-risk identification, and adsorptive purification of UDS desulfurization solvent under flowback-contamination conditions. Full article

The catalytic influence of γ-aminobutyric acid (GABA) on Zn²⁺ electroreduction at a mercury electrode was investigated in an acetate buffer. Electrochemical measurements, including DC polarography and differential capacity, indicate that GABA facilitates charge transfer through the formation of “cap-pair” surface bridges. This acceleration is reflected in a systematic increase in the standard rate constant and the transfer coefficient. Molecular dynamics simulations complement these findings by characterizing the conformational properties of GABA, showing a transition toward more folded forms in concentrated environments. Moreover, MD simulations demonstrate that GABA reduces the Zn²⁺ solvation number, providing a structural pathway that lowers the dehydration barrier prior to charge transfer. These observations correlate with the measured decrease in diffusion coefficients as the neurotransmitter concentration increases. The results establish a direct link between the zwitterionic adsorption of GABA and the reduction in the energetic barrier in the zinc electroreduction process. Full article

Coal mine methane (CMM) separation faces significant challenges due to high humidity and multicomponent conditions, under which the selective adsorption performance of CH₄ is substantially degraded compared with idealized laboratory scenarios. This review systematically analyzes the fundamental causes of this discrepancy by integrating water vapor occupation, competitive adsorption, and structural constraints into a unified framework. Water molecules preferentially occupy high-energy adsorption sites and reconstruct the interfacial energy landscape, while strongly adsorbing components such as CO₂ further suppress CH₄ uptake through competitive displacement. These coupled effects lead to a pronounced deviation between theoretical adsorption capacity and actual separation performance. To address this issue, this work proposes an evaluation paradigm centered on effective working capacity, which reflects the practically recoverable CH₄ under cyclic operation rather than equilibrium limits. The applicability of this framework is demonstrated through comparative analysis across different adsorbent systems, highlighting the critical roles of moisture resistance, structural stability, and competitive resilience. Finally, key material design strategies and process-level optimization approaches are discussed to enhance sustainable CH₄ separation under realistic conditions. This review provides a process-oriented perspective for bridging the gap between material performance and engineering application in CMM utilization. Full article

The bio-based biodegradable material poly(L-lactic acid) (PLLA) has received extensive attention due to its inherent sustainability. Ultra-high molecular weight (UHMW) PLLA possesses superior physical, chemical, and mechanical properties, but its difficulty in processing often restricts its further application. In this work, efficient preparation of UHMW PLLA fiber membranes using electro-blown spinning technology was reported for the first time. Thanks to the excellent electrostatic adsorption capacity brought by the piezoelectric properties of the prepared fiber membrane and its fluffy multi-scale structure, it demonstrates outstanding air filtration performance. The contradiction between filtration efficiency (>99.8% for PM_0.3) and pressure drop (~16 Pa) has been successfully balanced. It also demonstrated excellent moisture resistance, long-term stability, and dust-holding capacity. Especially compared with low molecular weight PLLA fiber membranes, the air filtration performance of UHMW PLLA fiber membranes have demonstrated excellent chemical stability. Meanwhile, its temperature stability can also meet the needs of most scenarios in life. This ensures the feasibility of practical application of the sustainable material PLLA in the field of air filtration. And due to its excellent filtration performance, it reduces energy consumption during use, thereby achieving sustainable development throughout the material’s entire life cycle. Full article