Search Results (8,070)

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

Lyophilized pectinase from Aspergillus niger (PeL) was immobilized onto polyamide 6 (PA6) microparticles (MPs) through an adsorption-based procedure within the pH range of 5–8, yielding four PeL@PA6 complexes. In contrast to commercial enological preparations that are complex enzymatic cocktails with unspecified exact compositions, the use of PeL with known specific activity enabled a more reliable evaluation and improvement of the immobilization process and of the structure–activity relationships of the resulting biocatalysts. Thermogravimetric analysis demonstrated better thermal stability of the PeL@PA6 complexes compared to neat PA6 MPs. UV-CD studies revealed that the secondary structure and conformational stability of PeL before and after immobilization were strongly pH-dependent, with maximum stability observed at pH 6–7. All four PeL@PA6 complexes retained significant catalytic activity and showed good tolerance to ethanol-rich media relevant to enological applications. Kinetic analysis indicated increased apparent K_m values after immobilization, suggesting diffusional limitations associated with the porous PA6 support. Clarification experiments of industrial white and rosé wine musts confirmed the practical applicability of the immobilized system. All PeL@PA6 complexes preserved the color and phenolic integrity of the musts, displayed good operational stability during reuse, and exhibited higher long-term storage stability than the free enzyme. These results demonstrate that PA6 MPs are promising supports for pectinase immobilization in wine clarification and related biotechnological applications. Full article

Bacterial decomposition of sweat produces odors affecting close-fitting garment comfort. This study selected five polyester filament types: coffee carbon polyester filament (CC-PET), bamboo charcoal polyester filament (BC-PET), oyster shell polyester filament (OS-PET), graphene polyester filament (GR-PET), and conventional polyester filament (C-PET). These four yarns exemplify three mainstream deodorizing mechanisms: BC-PET relies on physical adsorption through its porous structure; CC-PET combines adsorption with antibacterial moisture management to suppress odor at the source; GR-PET and OS-PET inhibit bacteria via reactive radicals from oxygen-containing groups and calcium oxide, respectively. Three structures were tested: weft flat knit, 1 × 1 rib, and 1 + 3 false rib. 1 + 1 rib and 1 + 3 false rib differ markedly in elasticity, thickness, and hand. Plain jersey is smooth, soft, and breathable with good extensibility. 1 + 1 rib delivers superior transverse elasticity and dimensional stability. 1 + 3 false rib is loftier and stiffer with enhanced shape retention and thermal insulation. Fifteen specimens were knitted on a seamless circular machine and evaluated using ammonia adsorption rate and acetic acid adsorption rate. Results show that fiber type significantly influences deodorizing performance, with the graphene polyester filament with the 1 + 3 false rib structure achieving the best adsorption for both gases. This provides a theoretical foundation for deodorizing functional fabric development. 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

Skin photoaging is closely associated with oxidative stress, inflammatory responses, and dysregulated collagen metabolism. Paeonol (Pae) possesses antioxidant and anti-inflammatory activities; however, its poor water solubility and short skin retention time limit its topical application. In this study, a transdermal delivery system based on a carboxymethyl chitosan (CMCS)/Carbomer 940 (Carb940) composite gel loaded with hydroxypropyl-β-cyclodextrin inclusion complexes of paeonol (Pae-CD) was developed. Pae-CD was prepared using an ultrasound-assisted saturated aqueous solution method, and the physicochemical properties, sustained-release behavior, transdermal permeation, antioxidant activity, and safety of Pae-CD/gel were evaluated. Furthermore, a mouse model of skin photoaging induced by combined ultraviolet A (UVA)/ultraviolet B (UVB) irradiation was established to investigate its reparative effects in vivo. The results showed that Pae-CD/gel exhibited a homogeneous three-dimensional porous structure, favorable sustained-release characteristics, enhanced skin retention capacity, and good cellular compatibility. In vivo experiments demonstrated that Pae-CD/gel markedly ameliorated ultraviolet-induced skin dryness, abnormal epidermal thickening, and dermal collagen loss. It also reduced oxidative stress and inflammatory factor levels, down-regulated matrix metalloproteinase-1 (MMP-1) and matrix metalloproteinase-3 (MMP-3) expression, and promoted the restoration of collagen type I (COL-1) and hydroxyproline (HYP) levels. Systemic safety evaluation revealed no obvious toxicity. In summary, Pae-CD/gel exerts antioxidant and anti-inflammatory effects and regulates collagen metabolism by enhancing transdermal delivery and local retention, thereby providing a safe and effective topical delivery strategy for the repair of skin photoaging. 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

Background: Three-dimensional printing (3DP) is rapidly advancing personalised medicine, yet systematic performance comparison with conventional manufacturing remains limited, particularly for plant-based formulations. Methods: This study compared tablets containing plant-based APIs (cannabidiol, apigenin, and luteolin) produced via conventional hot moulding and semi-solid extrusion (SSE) 3DP. The formulations were evaluated for physicochemical, mechanical, rheological, structural, and drug-release properties. Results: Both manufacturing methods produced tablets with comparable dimensions and mass; however, pronounced formulation-dependent differences were observed in mechanical strength, rheology, and microstructure. The molecular modelling predictions were consistent with the experimental findings. Agar–pectin exhibited the strongest predicted polymer–polymer and polymer–API interactions, including multiple hydrogen bonds, and formed a comparatively dense and cohesive matrix associated with slower API release. In contrast, the weaker interactions predicted for gelatine–pectin were associated with a less cohesive and more porous matrix that facilitated medium penetration, API diffusion, and drug release. SSE printlets generally exhibited greater porosity and more heterogeneous internal architectures than moulded tablets, resulting in enhanced drug release of approximately 95%. Micro-CT analysis provided important structural confirmation; API incorporation increased the void volume of gelatine–pectin printlets from 1.15% to 8.77%, demonstrating that disruption of polymer interactions contributed to pore formation and enhanced molecular diffusion. The observed release behaviour correlated with predicted molecular interactions and experimentally observed microstructural features, where increased porosity and weaker polymer–API interactions facilitated enhanced drug diffusion. Conclusions: Overall, SSE-3DP outperformed conventional moulding, demonstrating superior tunability and performance. This work provides a mechanistically informed strategy for designing plant-based, personalised natural products using 3DP technologies. Full article

Flexible pressure sensors featuring high sensitivity, a broad detection range, and excellent stability are pivotal components for high-precision electronic skins and human health monitoring. To circumvent the limitations of existing sensors in maintaining high responsiveness across extensive pressure ranges, herein, a novel flexible capacitive pressure sensor is developed based on a 3D porous ionogel foam composite (IL/EG/PVA@MF) coupled with a planar electrode array. This device leverages the synergistic structural engineering of the 3D hyperelastic melamine foam (MF) skeleton and the pressure-regulated fringe-field distribution and iontronic interfacial polarization of the porous ionogel. Experimental evaluations demonstrate that the sensor achieves a high normalized sensitivity of 62.45 kPa⁻¹ (2–10 kPa) and maintains reliable piecewise linear sensing performance across a broad working range of 0–50 kPa, accompanied by a rapid response time of within 8 ms. Furthermore, the sensor exhibits outstanding performance consistency after 6000 compression-release cycles at 50 kPa, verifying its good mechanical durability. In practical applications, the device can monitor diverse physiological signals with high fidelity, ranging from subtle radial artery pulses to large-scale joint movements and specific coughing patterns, underscoring its broad potential for integrated wearable systems and intelligent healthcare. 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

Flexible pressure sensors with porous structures are essential for wearable electronics and robotic perception. However, traditional porous flexible sensors suffer from poor stability and long recovery times. To address these challenges, a strategy integrating bionic architectures inspired by the rigid–flexible coupling structure of Bambusa textilis and the micro-protrusion structure of Salvia plebeia R.Br. is proposed. An aluminum sheet serves as the support layer, and the sensing layer is prepared through mold replication, material impregnation, and layer-by-layer assembly, offering a simple and scalable fabrication route. The sensor exhibits a broad effective pressure range of 0–31.5 kPa, with a minimum resolvable force of 0.2 N, and within its operating range (0–23.5 kPa), the relationship between resistance and pressure exhibits a trend that can be fitted to a quadratic term, with a coefficient of determination of 0.9986. It achieves a minimum response time of 350 ms and maintains stable signals under dynamic loading at different frequencies, indicating reliable detection of low-frequency weak pressures. After 5000 loading–unloading cycles, the device shows no obvious performance degradation. When mounted on a robotic foot, the sensor successfully distinguishes land, sponge, sand, and pebbles surfaces, demonstrating its potential for intelligent environmental perception. Full article

Oily wastewater commonly contains dissolved organic contaminants such as dyes, antibiotics, and phenolic compounds. Conventional stepwise treatment processes involve complex operation, high energy consumption, and severe membrane fouling. Multifunctional membranes integrating oil/water separation, pollutant adsorption or catalytic degradation, and membrane self-cleaning provide a promising solution for treating complex oily wastewater. This review summarizes recent advances in multifunctional membranes based on metal oxides, two-dimensional (2D) materials, three-dimensional (3D) porous structures, and biomass-derived materials. Key strategies, including micro and nanoscale structure regulation, wettability control, interlayer channel optimization, heterojunction construction, and active site engineering, are discussed together with the synergistic mechanisms involving oil/water separation, adsorption enrichment, photocatalysis, and Fenton reactions. Approaches for improving membrane flux, separation efficiency, degradation activity, antifouling performance, and cycling stability are also reviewed. Finally, challenges related to scalable fabrication, adaptability to real wastewater, long-term stability, and standardized evaluation are outlined, providing guidance for the design and practical application of multifunctional membranes. Full article

Hydrogen (H₂) detection under practical operating conditions requires sensing materials that simultaneously provide accessible reaction sites, efficient gas diffusion pathways, and fast interfacial charge transfer. Here, a hierarchical star-sphere ZnCo₂O₄ (ZC) architecture was integrated with graphene oxide (GO) and Pt supported on graphitized carbon (Pt/C) to develop hybrid chemiresistive sensing layers for low-temperature hydrogen detection. The synthesized ZC-based material exhibited a hierarchical morphology consisting of porous microspheres and star-shaped assemblies, providing a multiscale framework for gas access and surface reactions. By varying the GO content from 0.1 to 1 wt% at a fixed Pt/C loading, the ZC-0.5G composite achieved the most balanced structure, with well-distributed GO sheets, preserved star–sphere morphology, the highest specific surface area (53.6 m²/g), and the largest pore volume (0.09 cm³/g). The optimized sensor gave responses of 12.96%, 19.20%, 22.87%, and 26.43% for 500, 4000, 8000 and 10,000 ppm H₂ concentrations, respectively, with measurable response down to 50 ppm. The highest sensing performance was achieved at 50 °C and 60% relative humidity (RH), where the hierarchical oxide framework, GO-assisted interfacial pathways, and Pt catalytic sites acted in concert. The sensor also showed repeatable cyclic behavior and preferential response to H₂ compared to methanol, isopropanol, ethanol, acetone, and dimethylformamide. The improved sensing performance is attributed to the synergistic combination of the hierarchical ZC framework, GO-assisted interfacial pathways, and Pt-assisted catalytic activation, which together facilitate gas diffusion, surface reactions, and resistance modulation. Full article