Search Results (6,124)

The development of sustainable, biocompatible scaffolds with enhanced structural stability remains a primary challenge in bone tissue engineering. In this study, structurally reinforced nanocomposite scaffolds were successfully fabricated by integrating green-synthesized carbon quantum dots (CQDs) into a gelatin (G) matrix, offering an innovative platform that mimics the organic–inorganic interfaces of natural bone tissue. The CQDs were derived from oatmeal via a sustainable, green hydrothermal route, serving simultaneously as zero-dimensional reinforcing fillers and bioactive agents within the biopolymer network. To ensure an additive-free fabrication process that avoids toxic chemical cross-linkers, dehydrothermal (DHT) treatment was employed, successfully modulating the interfacial and chemical cross-linking interactions between the gelatin chains and the oxygen-rich surface groups of the CQDs. Structural characterization confirmed the uniform dispersion of CQDs (average diameter 7–8 nm) within the porous gelatin framework. The incorporation of CQDs significantly improved the physicochemical properties of the scaffolds; the G/CQD 5% formulation emerged as the optimal composition, exhibiting a 118% increase in compression modulus compared to pristine gelatin. The composite demonstrated tuned swelling kinetics and a significantly reduced degradation rate, restricting mass loss after 14 days of incubation to approximately 24% compared to 40% for pristine gelatin, which is essential for maintaining a structural template during the initial stages of tissue formation. Bioactivity assays in simulated body fluid (SBF) confirmed the rapid, biomimetic induction of a crystalline hydroxyapatite layer with a natural Ca/P ratio of 1.61 within 14 days. Furthermore, preliminary in vitro assessments using Human Skin Fibroblasts (HSFs) confirmed excellent general cytocompatibility, with cell viability exceeding 90%. This study highlights the unique potential of utilizing biomass-derived carbon nanostructures and clean manufacturing processing to engineer multifunctional scaffolds with enhanced structural stability and intrinsic bioactivity for potential bone defect repairs. Full article

This study aims to investigate the feasibility of ethanol-digested calcium oxide (CaO-E) as a novel dechlorination sorbent for the efficient removal of hydrogen chloride (HCl) from coal-fired flue gas and further evaluate its influence on mercury speciation and transformation in flue gas, thereby addressing the low efficiency and limited multi-pollutant control capability of conventional dry dechlorination technologies. Based on a laboratory-scale injection reaction system, ethanol-digested calcium-based sorbents were injected into simulated coal-fired flue gas to systematically examine the effects of key factors, including Ca/Cl molar ratio, SO₂, and fly ash, on dechlorination efficiency. Density functional theory (DFT) calculations were further employed to elucidate the reaction mechanisms. Meanwhile, mercury-laden flue gas was introduced to investigate the removal characteristics of elemental mercury (Hg⁰) and oxidized mercury (Hg²⁺) by CaO-E. The experimental results demonstrated that ethanol-digested CaO exhibited significantly superior performance compared with untreated samples, and the formation of a porous calcium hydroxide structure was identified as the key factor responsible for its high dechlorination efficiency. When the Ca/Cl molar ratio reached 4.0, the dechlorination efficiency could be stably maintained above 80%. SO₂ showed a pronounced inhibitory effect on the dechlorination process, whereas fly ash exhibited a slight promoting effect. Mercury removal experiments revealed that CaO-E had limited removal capability toward Hg⁰ but effectively reduced the concentration of Hg²⁺. Specifically, when the Ca/Cl molar ratios were 3 and 5, the Hg²⁺ concentrations decreased to 1.4 and 0.6 μg/m³, respectively. This behavior can be attributed to the fact that Hg²⁺ mainly exists in chlorinated forms such as HgCl₂, which possess strong polarity and can be readily adsorbed by the alkaline active sites on the CaO-E surface. In addition, as the dechlorination process proceeded, chlorine-containing species in the flue gas were gradually consumed, suppressing the oxidation conversion of Hg⁰ to Hg²⁺ and thereby further reducing the Hg²⁺ concentration. Theoretical calculations indicated that both HCl and SO₂ could undergo chemisorption on calcium active sites, while HCl possessed a lower reaction energy barrier and therefore dominated the competitive adsorption process, exhibiting preferential reactivity. Overall, ethanol-digested calcium oxide not only demonstrates excellent HCl removal performance, but also shows the capability to regulate mercury speciation in flue gas to a certain extent, providing both theoretical insights and technical support for the synergistic control of multiple pollutants in coal-fired flue gas. Full article

Three-dimensional images of multiphase natural and engineered materials obtained by X-ray micro-computed tomography require quantitative processing methods that can describe not only phase volume but also connectivity, spatial heterogeneity, and anisotropy. In this article, X-ray micro-computed tomography is abbreviated as X-$\mu$CT. Scalar descriptors such as fractal dimension, Betti numbers, Euler characteristic, and Minkowski functionals provide compact phase-level summaries of segmented X-$\mu$CT data, but they do not encode where structural heterogeneity occurs, whether connectivity is directionally spanning, how finite sample boundaries affect topological measurements, or how surface-normal orientation is distributed. We propose a unified methodological framework that extends scalar topological and Minkowski-functional analysis of segmented multiphase 3D images by adding cut-response analysis, including its boundary-sensitivity interpretation, directional connectivity and orientation descriptors, and the rank-two surface Minkowski tensor $W_1^{0,2}$. The framework is demonstrated on a previously published segmented geological X-$\mu$CT volume used as a benchmark multiphase geometry with four X-ray-density phases and on synthetic validation geometries with analytically known topology. The results show that the proposed extensions reveal spatial sensitivity, boundary-to-boundary connectivity, and surface fabric that are not captured by scalar phase-level invariants alone. The proposed framework can be used to analyze segmented 3D images of multiphase geological, porous, composite, and engineered samples, thereby expanding quantitative knowledge about their internal structure beyond scalar phase-level descriptors. Full article

Superhydrophobic SiO₂ nanofibers were deposited on copper foam substrates via micro/nano surface modification to improve the pool boiling heat transfer performance of porous copper media. By adopting an electrospinning technique, uniform and robust superhydrophobic SiO₂ nanofibers were firmly deposited on copper foam skeletons, forming interconnected porous structures with intrinsic superhydrophobic characteristics. The fabricated superhydrophobic nanofiber structures greatly reduce bubble nucleation resistance and provide sufficient stable vaporization sites, effectively promoting boiling heat transfer enhancement. Experimental results verify that surface modification with superhydrophobic SiO₂ nanofibers significantly improves the overall boiling performance of copper foam. The sample with a nanofiber loading of 1.8 mg achieves the optimal thermal performance, presenting lower wall superheat, higher critical heat flux, and an improved heat transfer coefficient. CFD simulations were conducted, and the numerical results exhibit good consistency with experimental measurements. Full article

Natural wood possesses a hierarchically porous and anisotropic structure, which provides a foundation for functional utilization, but its flammability and hygroscopicity limit its applications. Conventional bulk impregnation modification involves introducing functional agents throughout the entire pore system. This approach can enhance performance, but inevitably leads to lumen occlusion and increased density. To address this trade-off, researchers have recently developed micronano coating strategies based on interfacial decoration rather than bulk deposition within the lumina. These strategies confine functional components to cell wall surfaces while preserving the natural porous scaffold. Two fabrication routes have been developed, namely liquid-phase methods and gas-phase methods, which differ in coating precision, penetration depth, and interfacial bonding. In flame retardancy, interfacial coatings act as physical barriers and promote chemical charring. Inorganic layers suppress oxygen diffusion and heat transfer, while phosphorus or nitrogen components catalyze cellulose dehydration. In acoustics, conformal coatings regulate pore wall roughness and acoustic impedance, enhancing viscous and thermal dissipation without blocking channels. Challenges for practical application include mass transfer limitations in large logs, conflicts between high-precision processes and industrial economics, and interfacial durability under service conditions. This narrative review summarizes fabrication strategies, flame-retardant mechanisms, and acoustic regulation principles, providing guidance for coating strategy selection and process optimization. It is noted that this review focuses on wood species with open, permeable pore structures suitable for functional modification, rather than species whose pores are occluded by heartwood extractives. Full article

Androgenetic alopecia (AGA) is a prevalent clinical disorder, and the key pathogenic factor is dihydrotestosterone (DHT) present in the pilosebaceous unit. Current clinical therapeutic options are often associated with notable adverse effects, highlighting the urgent need for safer and more effective interventions. Herein, a novel amphiphilic covalent organic framework (amCOF) is designed and synthesized. By simultaneously incorporating hydrophilic functional groups and lipophilic alkyl chains into the covalent organic skeleton, the material exhibits excellent amphiphilicity, high specific surface area, and well-ordered porous structures. Owing to its amphiphilic nature, amCOF disperses uniformly in aqueous physiological media and adapts favorably to the lipophilic microenvironment within hair follicles. Furthermore, the ordered porous architecture endows amCOF with rapid DHT adsorption kinetics, high adsorption capacity, and high removal efficiency. Functional assays demonstrate that amCOF effectively reverses the inhibitory effects of DHT on the proliferation and migration of human dermal papilla cells. In animal models, topical application of amCOF significantly reduces local DHT concentrations, promotes hair regrowth, and shows favorable biosafety profiles. Collectively, this work provides a new strategy for treating androgenetic alopecia by scavenging pathogenic lipophilic molecules from sebum using amphiphilic porous materials and also establishes a solid foundation for expanding the biomedical applications of COFs. Full article

Ammonia, a toxic and volatile pollutant commonly found in chemical industrial environments, requires reliable real-time detection to ensure industrial safety and effective environmental monitoring. Conventional gas sensors typically operate at elevated temperatures, resulting in high power consumption. Moreover, pure metal oxides and conductive polymers often suffer from significant aggregation and exhibit suboptimal sensing performance under ambient conditions, limiting their practical applications. In this study, hierarchical porous V₂O₅/PANI composites were synthesized via a straightforward one-step coprecipitation method combined with in situ polymerization. The interlaced architecture of polyaniline (PANI) and vanadium pentoxide (V₂O₅) effectively reduces structural aggregation and increases the availability of surface active sites. Furthermore, the synergistic interaction at the bi-phase interface significantly enhances charge carrier transport, leading to improved ammonia-sensing capabilities at room temperature. Notably, the composite containing 20% V₂O₅ demonstrated superior response, selectivity, and reproducibility toward 10 ppm NH₃. Due to its simple fabrication process and room-temperature operation without external heating, the developed V₂O₅/PANI composite sensor holds significant potential for practical applications in low-concentration ammonia detection under ambient conditions. Full article

In recent decades, due to the rapid development and application of wireless communication, flexible electronics, and smart devices, electromagnetic interference (EMI) and radiation pollution have been intensified, creating an urgent demand for efficient EMI shielding materials. Carbon nanostructures such as graphene and carbon nanotubes are considered promising candidates due to their excellent properties, such as high electrical conductivity, low density, large specific surface area, and flexibility. This work reports our recent results in the design and testing of polymer nanocomposites with irradiated hybrid carbon nanostructure (graphene/multi-walled carbon nanotubes) used as EMI shielding materials. Five representative composites with varying filler loadings (AH of 15% and AM1 of 20 wt%), thicknesses (0.208–0.48 mm), and e-beam irradiation doses (from 50 to 400 kGy) were systematically characterized using SEM, FTIR, TGA/DSC, and vector network analyzer (VNA) measurements in the S-band (2.65–3.90 GHz). The effects of different e-beam irradiation doses and hybrid carbon contents on conductive network construction, interface engineering, and porous or layered structures on EMI shielding performance are discussed. Experimental results show that all studied composites exhibited strong absorption-dominant behavior (SE_A), while the multiple reflection component (SE_M) was found to be negligible. Both filler loading and sample thickness significantly enhanced shielding performance, with a pronounced synergistic interaction observed between these parameters. A quadratic Response Surface Methodology (RSM) model was developed to correlate the total shielding effectiveness (SE_T) with thickness and filler content, yielding high predictive accuracy (R² > 0.96). The model enables efficient optimization of composite design for targeted shielding levels. Full article

Activated carbon is a highly porous adsorbent material that is often used to treat wastewater using physical and chemical adsorption. Agricultural and urban biomass waste valorization to activated carbon is a low-cost, renewable solution to commercial adsorbents, and can help prevent waste from tree pruning from being dumped in landfills or openly burned. In this study, the ability of the ground and unground Ficus nitida leaves to efficiently adsorb Rhodamine B dye and total chromium from model aqueous solutions was investigated. Chemical activation was performed using phosphoric acid (H₃PO₄) at different impregnation ratios (1:1, 2:1, and 4:1). Samples obtained as a result of the above activation were labeled G1–G3 (ground) and UG1–UG3 (unground). The adsorption test showed that the samples with the highest activation ratio (G3 and UG3) gave the best results, removing 92% and 94% RhB, respectively, in 20 minutes. After 24 h, sample G3 showed the best efficiency of 73.31% (13.35 ppm remaining) in chromium removal, where the adsorption kinetics were well described by the pseudo-second-order model (R² > 0.98), indicating that there may be some chemical interactions occurring during the adsorption process along with physisorption, and the RhB adsorption isotherms for sample UG3 were well described by the Langmuir isotherm (R² > 0.95). The higher activation ratio and grinding increased the carbon content (up to 90% C for G3), surface functional groups, and textural properties (BET surface area of 699 m²/g and total pore volume of 3.06 cm³/g). Furthermore, reusability tests over five consecutive cycles demonstrated the excellent recyclability of sample G3, retaining removal efficiencies of 80.5% for RhB and 50.2% for total chromium. The results revealed that Ficus nitida leaf-based AC can be used as an efficient, economical, and reusable adsorbent material for sustainable environmental cleanup and water purification systems and will create a circular economy for waste management. Full article

In recent years, in the presence of environmental pollution, green materials have emerged as a research hotspot. The value-engineered design of electron nanocatalysts using low-cost biomaterials has demonstrated special electrocatalytic efficiency and performance in methanol oxidation reactions within direct methanol fuel cells (DMFCs). These electro/nanocatalysts were successfully heat-treated in a study involving multiple temperature controls and activation. The research involved studying samples C-400, C-600, and C-800, which were carbonized at temperatures of 400, 600, and 800 °C from snail shells. Next, these samples were activated using potassium hydroxide, resulting in samples AC-400, AC-600, and AC-800. Moreover, the ability of the resulting electron nanocatalysts, as heat-treated catalysts, to enhance the electrocatalytic efficiency of methanol oxidation reactions, along with the significant effects of temperature variations before and after activation, was investigated. The surface area of the sample increased successfully from 4.6691 m²/g to 14.1763 m²/g after activation, while the pore volume increased from 0.02225 m³/g to 0.07233 m³/g. The results clearly show that methanol oxidation reactions were more efficient and active on the surface of the electron nanocatalyst at 800 °C (AC-800). The current density successfully increased from 22.76 mA/cm² to 49.89 mA/cm² after the addition of methanol to C-800, whereas it increased significantly from 25.7 mA/cm² to 65.24 mA/cm² in AC-800 (after activation). Furthermore, the C-400, C-600, C-800, AC-400, AC-600, and AC-800 electro/nanocatalysts exhibited novel power densities of 12.6, 18.2, 29.7, 16.6, 22.86, and 39.56 mW/cm², respectively. This was further confirmed by their morphological, structural, and electrochemical characteristics. The synthesized materials are proven to be sustainable carbon materials for electron nanocatalyst support and methanol electro-oxidation in DMFC systems because of their low cost, eco-friendliness, high performance, and enhanced porous structure. Moreover, this research provides an effective waste-to-energy approach for converting snail shell biomass into valuable functional carbon materials for renewable energy applications. Full article

Lithium–sulfur (Li-S) batteries are widely regarded as one of the most promising candidates for next-generation electrochemical energy storage, owing to their very high theoretical energy density and reliance on abundant, low-cost elements. However, the practical deployment of Li-S technology remains severely constrained by the polysulfide shuttle effect, originating from the dissolution, migration and parasitic redox cycling of lithium polysulfide intermediates, which leads to rapid capacity fading, low coulombic efficiency and incompatibility with industrial carbonate-based electrolytes. Recent reports on the formation and stabilization of γ-sulfur, a rare monoclinic allotrope, within porous carbon matrices have identified a prospective direction in sulfur electrochemistry, theoretically enabling polysulfide-free cycling and improved stability, also in conventional carbonate electrolytes. These findings challenge the long-held assumption that polysulfide formation is unavoidable in sulfur cathodes and suggest that control over sulfur allotropy and nanoconfinement, as well as carbon–sulfur chemistry, may unlock previously inaccessible performance and integration windows for metal–sulfur batteries, including most technologically advanced Li-S batteries. Based on recent studies, this Perspective article critically evaluates the evidence for γ-sulfur stabilization in carbon hosts, discusses the interplay between pore geometry, carbon surface chemistry and sulfur speciation, and finally identifies key knowledge gaps. Full article

Two-dimensional GaS_xTe_1−x alloy nanosheets with different compositions were synthesized by chemical vapor deposition using GaS and GaTe powders as precursors. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses confirmed their sheet-like morphology and the uniform distribution of S and Te, while Raman and photoluminescence measurements revealed composition-dependent vibrational and emission characteristics. Te-rich samples exhibited position-dependent emission ranging from the red to the near-infrared region, whereas increasing the S content gradually shifted the emission toward the blue-green region. Among the synthesized samples, GaS_0.9Te_0.1 showed a relatively stable photoluminescence peak near 520 nm and was therefore selected as a fluorescent powder for latent fingermark development. Its performance was evaluated on glass, stainless steel, plastic, and ceramic surfaces and compared with that of silver powder, gold powder, and commercial red fluorescent powder. GaS_0.9Te_0.1 produced clear fluorescent ridge patterns and strong background contrast, particularly on glass, plastic, and white ceramic. The mean contrast across the four substrates reached 25.83, exceeding that of the reference powders. These results demonstrate that GaS_xTe_1−x nanosheets possess tunable optical properties and that GaS_0.9Te_0.1 is a promising fluorescent material for latent fingermark development on non-porous surfaces. Full article

Triply Periodic Minimal Surfaces (TPMSs) represent a progressive class of cellular materials with high potential for high-tech applications. This review provides a comprehensive analysis of TPMS architectures, linking their mathematical underpinnings and advanced CAD modeling in PTC Creo Parametric 12 with technological aspects of additive manufacturing and macroscopic mechanical response. The work critically compares dominant topologies such as Schoen Gyroid, Schwarz Diamond, and Schwarz Primitive, focusing on the differences between uniform and functionally graded (FG-TPMS) structures. From a production perspective, this study identifies key process limitations of PBF-LB/M and SLA additive technologies, in particular the issues of unsintered powder accumulation, geometric deviations, and the negative impact of surface roughness (satellite particles) on fatigue life. Analysis of mechanical behavior confirms the superiority of sheet-based modifications in kinetic energy absorption, where specifically tailored FG-TPMS topologies exhibit stable deformation plateaus and controlled, progressive failure modes under compression. The conclusion of the work summarizes established applications in biomedical engineering for the elimination of stress shielding, as well as emerging trends in the field of 4D printing and acoustic metamaterials. This review serves as a comprehensive engineering guide for the optimization and implementation of next-generation porous structures. Full article

Traditional petroleum coke-based porous carbons suffer from low specific surface area, insufficient surface active sites, and inferior rate and cycling performance. Herein, a series of sulfur/fluorine-co-doped hierarchical porous carbon (S+F-PC) cathode materials were synthesized controllably from industrial solid-waste petroleum coke via KOH high-temperature activation and heteroatom doping strategies. Polyaniline/carbon nanotube (PANI/CNTs) core–shell composites were fabricated as anodes through in situ oxidative polymerization, and S+F-PC//PANI/CNT asymmetric aqueous supercapacitors were assembled. The structural and chemical modulation mechanisms of dual heteroatom doping, as well as the electrochemical energy storage kinetics of electrodes and devices, were systematically investigated using SEM, TEM, XRD, XPS, BET, CV, GCD, EIS, and long-cycle tests. The results verify the synergistic modification effect of sulfur and fluorine co-doping. S-induced lattice distortion creates abundant mesopores and pseudocapacitive active sites, while F atoms stabilize the carbon skeleton to avoid high-temperature structural collapse and enhance the graphitization degree. The optimized S+F-PC exhibits an interconnected micropore–mesopore–macropore hierarchical network and a specific surface area of 172.2 m²/g, delivering a high specific capacitance of 477 F/g at 1 A/g, outperforming pure PC, and single-S-doped and -F-doped counterparts. The PANI/CNTs core–shell structure effectively alleviates the volume expansion of PANI during cycling, and the one-dimensional CNTs form a continuous conductive network. The PANI/CNT anode achieves a specific capacitance of 417 F/g, with a capacity retention of 91.4%, after 10,000 cycles. The assembled asymmetric supercapacitor realizes a stable voltage window of 1.6 V. It presents a specific capacitance of 117 F/g at 1 A/g, a maximum energy density of 41 Wh/kg at a power density of 2000 W/kg, and 87.2% capacity retention after 10,000 cycles. This work provides a feasible strategy for the high-value recycling of industrial-waste petroleum coke and the design of high-performance heteroatom-doped carbon electrodes and matched asymmetric aqueous supercapacitors. Full article

Biowaste-derived porous carbon materials show promise as electrode materials for supercapacitors owing to their low cost, renewable nature, widespread availability, and high specific surface area. Herein, boron and nitrogen co-doped porous carbon was synthesized via a facile one-step activation approach using reed spike as carbon precursor, ammonium borate as both the nitrogen and boron source, and potassium bicarbonate as activator. The prepared PC-700 materials possess large specific surface areas with hierarchical porous architectures and rich N (2.54 at%), O (11.23 at%) and B (2.59 at%) functional groups. As an electrode material, the PC-700 materials show a specific capacitance of 329.6 F g⁻¹ at 0.5 A g⁻¹ and long lifespan. Notably, the assembled PC-700 symmetric super capacitor achieves an energy density of 20.5 Wh kg⁻¹ and excellent electrochemical stabilization (98.60% capacity retention after 10,000 cycles). Full article