Search Results (7,796)

To address cathode passivation, performance deterioration, and toxic stress during the removal of hexavalent chromium [Cr(VI)] in biocathode microbial fuel cells (MFCs), this study constructed nanomaterial-hybridized biocathodes to improve electricity generation and Cr(VI) removal in MFCs. Reduced graphene oxide (rGO), nano-iron sulfide (nano-FeS), and rGO/nano-FeS were separately hybridized with biocathodes to systematically investigate the effects of different hybridized biocathodes on the performance of MFCs for Cr(VI)-containing wastewater treatment. The results showed that the FeS group exhibited the best Cr(VI) removal capability, with a maximum removal kinetic constant of 0.184 h⁻¹, which was 3.60 times that of the Control group, and showed the smallest performance decline after three consecutive cycles. Mechanistic analysis indicated that nano-FeS promoted the transformation of Cr(VI) into Cr(III) and Cr(0) through its strong adsorption and reducing capacities; it also enhanced biofilm cell activity and the protein/polysaccharide ratio in extracellular polymeric substances; furthermore, it shaped a multi-taxon-dominated microbial community capable of Cr(VI) tolerance and reduction and enhanced the associated metabolic functions, thereby improving resistance to Cr(VI) stress and effectively alleviating cathode passivation. In contrast, rGO tended to enhance biocathode conductivity and electricity generation in MFCs, with the rGO + FeS group achieving the highest power density output of 51.54 ± 3.62 mW/m², which was 1.22 times that of the Control group, as well as the smallest decline in power density after three consecutive cycles. Overall, nanomaterial hybridization reshaped interfacial electron transfer and microbial stress resistance in biocathodes, enabling efficient Cr(VI) removal and stable electricity generation, and providing a new strategy to construct long-term stable bioelectrochemical systems for heavy metal-containing wastewater treatment. Full article

Flexible pressure sensors serve as core sensing components for wearable health monitoring systems, electronic skins for soft robots, and flexible human–machine interaction devices. Benefiting from the interfacial electric double-layer polarization effect, iontronic sensing delivers far higher pressure response sensitivity than conventional parallel-plate capacitive sensors, endowing it with distinctive advantages in the detection of weak physiological signals. Nevertheless, current dense ionic thin-film dielectric layers suffer from limited deformation space under compression and poor low-pressure sensing capability. Mainstream high-precision micropillar arrays are fabricated via photolithography, 3D printing, and metal etching molds, which require costly equipment and complicated fabrication procedures, making large-area mass production unfeasible. Random frosted concave-convex microstructures feature disordered dimensions, leading to severe device hysteresis and narrow linear ranges, which fail to achieve ultrahigh sensitivity alongside a wide pressure detection range simultaneously. To address the aforementioned multiple bottlenecks, this paper proposes a low-cost resin template replication process to fabricate TPU-based ionic thin-film dielectric layers with ordered micropillar array microstructures. Combined with inkjet-printed silver conductive PI flexible electrodes, an iontronic flexible pressure sensor with a sandwich layered structure is constructed. Multi-dimensional investigations including microscopic morphology characterization, electromechanical sensing performance calibration, and human wearable application tests are systematically implemented to thoroughly elucidate the synergistic enhancement mechanism of the arrayed micropillars. Test results demonstrate that the effective pressure detection range of the sensor spans 0–1038 kPa, accommodating ultra-low pressures such as pulse signals as well as medium-to-high-pressure loads including joint bending. The sensitivity reaches 23.27 kPa⁻¹ within the low-pressure range of 0–200 kPa and remains stable at 3.52 kPa⁻¹ in the high-pressure range of 200–1038 kPa, with piecewise linear fitting correlation coefficients of 0.93 and 0.96 respectively. Both the response time and recovery time of the device are 40 ms, and the hysteresis error throughout the loading-unloading cycle is merely 2.62%. After 20,000 consecutive cyclic loading-unloading tests, the peak capacitance output only decays by 5.1%, verifying outstanding mechanical fatigue resistance and electrical stability. Validations in multi-scenario applications prove that the sensor can accurately capture human physiological and motion signals including radial artery pulses, laryngeal deformation induced by multi-syllable vocalization, and multi-angle bending of fingers and elbow joints, suitable for home-based health monitoring, quantitative rehabilitation training, flexible tactile interaction and other scenarios. The entire fabrication process eliminates high-precision micro-nano processing equipment such as photolithography systems, plasma etchers and 3D printers; only general chemical raw materials and conventional laboratory instruments are adopted. The reusable templates enable low manufacturing costs and large-area coating forming, offering a novel low-cost technical solution for the engineering implementation and industrialization of high-performance iontronic flexible pressure sensors. Full article

This study presents an electrothermal coating approach for synthesizing cell-imprinted polymers (CIPs) on metallic microwires through localized resistive heating-induced polymerization. Imprinted polymers (IPs) are robust, cost-effective synthetic affinity materials widely used in sensing applications. However, conventional fabrication methods, including bulk and suspension polymerization, often lack spatial control, producing non-specific polymerization, heterogeneous coatings, and reduced sensor reproducibility. Electrochemical polymerization provides improved spatial control but requires specialized instrumentation and restricts monomer selection. Here, applying direct current (DC) to metallic microwires immersed in a prepolymer solution generated localized Joule heating, enabling controlled in situ polymerization and uniform coatings while minimizing undesired bulk polymerization. By optimizing the applied current and polymerization time, CIP coatings with tunable thicknesses were fabricated on gold-coated microwires. Under optimized conditions, ~6 µm thick coatings were imprinted using Salmonella templates. Scanning electron microscopy revealed bacteria-shaped cavities consistent with template removal and the formation of imprinted cavities. Rebinding experiments demonstrated enhanced bacterial capture, with CIP-coated microwires achieving ~70% capture efficiency, compared to 22% for bare microwires and 33% for non-imprinted polymer (NIP) controls. These results support the effectiveness of the proposed method for localized polymerization and demonstrate the enhanced capture of the template species by CIP-coated microwires relative to bare microwires and NIP-coated controls. Full article

Metal corrosion and microbial contamination cause severe damage to marine facilities and result in immeasurable economic losses. Highly efficient and durable anti-corrosion and anti-fouling coatings represent the most effective solution strategy widely employed, whilst two-dimensional graphitic carbon nitride (g-C₃N₄), owing to its non-toxic and highly effective properties, is frequently utilized as a coating filler. Herein, this work innovatively engineered g-C₃N₄ into rod-like structures with layer-oriented alignment through a two-step simplified synthesis process, naturally achieving the self-assembly integration of ultrathin sheets. Subsequently, the special rod-like g-C₃N₄ (RCN) was blended with a polydimethylsiloxane (PDMS) matrix, ultimately yielding a multifunctional nanocomposite coating (RCN/PDMS) that combines mechanical reinforcement, long-term corrosion resistance, and microbial fouling protection. Notably, the compact lamellar structure within uniformly dispersed RCN particles in the polymer matrix effectively enhances the crosslinking density of the composite, significantly improving the coating’s adhesion and tensile strength (1.795 MPa). Furthermore, upon exposure to light, the modified RCN-2 releases substantial reactive oxygen species (ROS), exhibiting pronounced antibacterial activity (90.3% of E. coli and 95.1% of S. aureus) against surface-adhering microorganisms. Following a 60 d marine immersion simulation test, the impedance arc radius of the RCN-2/PDMS coating remained as high as 5.17 × 10⁹ Ω·cm², representing an improvement of nearly two orders of magnitude over pure PDMS coatings. This work expands the application of morphology-controlled g-C₃N₄-based fillers in marine anti-fouling and anticorrosion coatings. Full article

Electrocatalytic glycerol oxidation to formic acid (FA) offers a sustainable route for biomass valorization, yet non-noble metal catalysts generally suffer from sluggish C-C bond cleavage and poor product selectivity. Here we report an amorphous nickel–cobalt oxyhydroxide bearing both metal and oxygen vacancies (D-NiCoO_xH_y-V_Cr,O), grown on nickel foam via one-step electrodeposition followed by electrochemical activation with Cr doping. The coexistence of the dual vacancies is experimentally confirmed by X-ray photoelectron spectroscopy (XPS), which reveals elevated Ni³⁺/Co³⁺ ratios and reduced lattice oxygen, and by electron paramagnetic resonance (EPR), which shows a markedly enhanced signal at g = 2.003. Building on prior Cr-leaching approaches in single-metal nickel oxides, this work extends dual-vacancy engineering to an amorphous bimetallic NiCo oxyhydroxide and correlates the defect structure with glycerol-induced interfacial responses, charge-transfer behavior, and product selectivity. The catalyst delivers 200 mA cm⁻² at 1.31 V vs. RHE and achieves 100% Faradaic efficiency for formate at 1.32 V vs. RHE. In situ electrochemical impedance spectroscopy further reveals a significantly reduced charge-transfer resistance. These results establish Cr-assisted dual-vacancy engineering in amorphous bimetallic oxyhydroxides as a promising strategy for selective biomass electrooxidation. Full article

Water-cooled tungsten targets may remain in contact with stagnant deionized water during accelerator shutdown, creating a beam-off corrosion condition distinct from irradiation-assisted service. Untreated tungsten (W), laser-ablated tungsten (LA-W), and a 500 nm tantalum-coated laser-ablated tungsten surface (Ta-LA-W) were therefore immersed in deionized water for up to 28 days. Laser ablation replaced the machined surface with a hierarchical micro/nanostructure and increased the areal roughness Sa from 0.22 ± 0.01 to 1.75 ± 0.07 μm; after Ta deposition, Sa was 1.62 μm. LA-W exhibited the largest topographic attenuation and the highest dissolved W concentration, reaching 7.915 mg·L⁻¹ at 21 days. Ta-LA-W maintained Sa within the range from 1.60 ± 0.06 to 1.66 ± 0.07 μm and limited dissolved W to 1.118–1.601 mg·L⁻¹. X-ray photoelectron spectroscopy showed increased WOx-related intensity and disappearance of the metallic-W loss feature only for untreated W. The W 4f envelopes of LA-W and Ta-LA-W remained broadly similar before and after immersion, but for different reasons: sustained W dissolution for LA-W and suppression of W oxidation and release by the Ta-containing barrier for Ta-LA-W. The dissolution-based corrosion sequence was LA-W > W > Ta-LA-W. Laser texturing therefore acted as an interfacial-engineering treatment rather than an intrinsically corrosion-resistant modification. Full article

Nickel release from metallic items is the leading cause of allergic contact dermatitis, and preventive strategies require both reliable detection tools and materials capable of limiting skin exposure. In this work, we propose dual-function bioplastic coatings based on starch, glycerol, and cellulose derivatives incorporating dimethylglyoxime (DMG) and a pH-10 borate buffer to enable colorimetric nickel sensing directly in the solid state. The Ni–DMG assay was first optimized in solution through UV-Vis spectroscopy and a Central Composite Face-Centered Design, identifying reagent concentrations that maximize linearity while minimizing detection limits. These conditions were transferred to bioplastic films prepared using carboxymethyl cellulose (CMC) or quaternized hydroxyethyl cellulose ethoxylate (QHECE). The materials were characterized by FT-IR spectroscopy and Principal Component Analysis, while gravimetric tests assessed hydrophilicity. Both bioplastics showed clear and reproducible colorimetric responses upon nickel exposure, and multivariate models built from RGB values and UV-Vis spectra enabled quantitative prediction of Ni²⁺ content. However, the proof-of-concept experiment revealed insufficient resistance to prolonged moisture, with films softening and partially losing cohesion under conditions mimicking skin perspiration. These results demonstrate that the sensing mechanism is robust, but the current bioplastic formulation requires improved water resistance before practical deployment as protective coatings for jewelry. Full article

Corrosion-resistant coatings with a double-layer structure are deposited on the surface of S30408 stainless steel at welding currents of 170 A, 200 A, and 230 A using metal active gas (MAG) arc welding technology. The influence of welding current on the microstructure, microhardness, wear resistance, and electrochemical corrosion behavior of the coating is systematically studied. The results show that the coating produced at 200 A exhibited the finest martensitic structure, the highest microhardness (~450 HV), and the lowest mass loss (139.9 mg), indicating its superior wear resistance. In contrast, the coating fabricated at 230 A displayed the most positive corrosion potential (−0.302 V vs. saturated calomel electrode (SCE)) in 3.5 wt.% NaCl solution, which is attributed to enhanced elemental homogenization arising from the higher heat input. This paper clarifies the critical role of welding current in balancing wear and corrosion performance and provides a practical guideline for the cost-effective surface enhancement of S30408 steel components. Full article

Flexible transparent conductive films with symmetric and asymmetric multilayered structures are studied using the ZnS–TiO₂–Ag material system, in order to capitalize on the divergent properties of the two dielectric layers for improved performance. The dielectric/metal/dielectric-structured films were deposited by magnetron sputtering sequentially, with high-purity targets. Multilayered films with various dielectric combinations and metallic layer thicknesses were prepared and analyzed. The surface morphology and phase structure were characterized by atomic force microscopy and scanning electronic microscopy. The optical properties were tested by spectrophotometry and analyzed by numerical simulation approach. The sheet resistance was measured via a four-point probe tester. Among the series of multilayers, asymmetric ZnS/Ag/TiO₂ film with 35 nm thickness of dielectric layers and 8.5 nm of metallic layer possesses the optimum comprehensive optoelectronic performance. The average light transmittance reaches 90.72% in the visible spectrum, and the sheet resistance is 7.69 Ω/sq. The good result is ascribed primarily to the combined advantages of superior percolation effect of bottom ZnS layer on ultrathin Ag layer, beneficial impingement effect of top layer deposition on the metallic layer, and excellent surface smoothness of the top dielectric layer. Full article

High-entropy alloys (HEAs) are a unique metallic alloy that was initially recognized for the possibility of stabilizing simple solid-solution phases through high configurational entropy. Research over the past two decades, however, has shown that their behavior is far more complex. Phase formation, microstructural evolution, and surface performance arise from the combined influence of composition, atomic interactions, processing history, and the surrounding environment. This paper reviews the connections between these aspects moving from the bulk alloy to the surface. The thermodynamic and empirical criteria utilized for prediction of phase formation and reasons behind ignoring the factors such as ordering, segregation, metastability, and processing defects are described. Further, the influence of casting, rapid solidification, coating deposition, and thin-film processing on the microstructure that will interact with catalytic or corrosive environment is reviewed. Electrocatalysis and corrosion resistance are considered as two strongly coupled surface phenomena rather than separate fields of application. Quantitative comparison of exemplary high-entropy alloy systems shows the influence of the alloying approach and surface development on the catalytic properties, surface reconstruction, selective dissolution, passive film formation, and localized corrosion. The potential of CALPHAD modeling, density functional theory, machine learning, and multi-objective optimization for a better alloy selection in the field of high-entropy alloys is reviewed as well. We identified that the success of HEA design is not only in choosing the right composition but rather in controlling the phases, defects, interfaces, and surface of the HEA. Full article

Current airway stents, including silicone and metallic devices, remain associated with important complications such as migration, restenosis, mucus retention and the need for repeated interventions. Biodegradable stents offer a promising alternative by providing temporary mechanical support while avoiding the long-term presence of a permanent implant. However, the influence of stent geometry and material properties on their mechanical performance and interaction with airway tissue is still not fully understood. This study presents a computational framework integrating computer-aided design and finite element analysis to investigate the mechanical behaviour of biodegradable tracheobronchial stents. Two stent architectures (X-pattern and W-pattern) were analysed over a range of wire thicknesses using two biodegradable materials: a PLA/PCL; 70/30 wt.% blend and AZ31 magnesium alloy. Radial compression, diameter recovery after radial compression and stent–tissue interaction simulations were performed to evaluate the influence of geometry, material selection and design parameters on device performance. The results suggested that both stent geometry and material properties strongly influence the mechanical behaviour of biodegradable airway stents, although they affect different aspects of the stent–tissue interaction. The X-pattern consistently exhibited greater resistance to radial compression, lower elastic diameter recovery after radial compression and improved maintenance of the expanded lumen compared with the W-pattern. Material properties primarily affected the magnitude of the mechanical response, as further confirmed by the quantitative contact-pressure analysis, with AZ31 providing greater radial support, while the spatial distributions of stress and strain within the tracheal wall were mainly governed by the stent architecture. Based on the computational analyses, X-pattern stents manufactured from the PLA/PCL; 70/30 wt.% blend were selected for in vivo evaluation in a rabbit model. Endoscopic observations revealed tissue features that were qualitatively consistent with the mechanical patterns predicted by the numerical simulations, although no direct causal relationship can be established from the available observations. These findings support the ability of the proposed framework to represent the principal aspects of stent–tissue interaction. The proposed computational framework provides a practical tool for the rational design and mechanical assessment of biodegradable airway stents and may facilitate the future development of customised airway prostheses. Full article

Ultrafast laser processing enables the creation of functional surfaces in metals, semiconductors, ceramics, polymers and other materials through spatially controlled nonequilibrium energy deposition. However, the resulting surface functionality cannot be explained solely by laser parameters or geometric features. Femtosecond irradiation induces a sequence of coupled processes, including nanoscale structuring, phase transformation, chemical modification, defect formation, and relaxation, which define the final surface state. This review introduces the Surface-by-Design concept, where functional surfaces are considered as engineered material states formed through controlled laser–matter interaction rather than as predefined patterns. Representative examples including laser-induced periodic surface structures, hierarchical micro/nanotextures, modified oxide layers, and laser-generated functional interfaces are analyzed in relation to wettability, tribological behavior, corrosion resistance, optical response, and other properties. The review further examines how advanced characterization, digital engineering, beam shaping, in situ diagnostics, and data-driven methods contribute to controlling surface evolution. Remaining challenges include reproducibility, scalability, and reliable prediction of functional behavior during service conditions. Future progress in femtosecond laser surface engineering will depend on the ability to control not only the generated morphology but also the evolving structural and physicochemical state of functional interfaces. Full article

Chronic wounds are complex environments marked by persistent inflammation, oxidative stress, hypoxia, and conditions that favor antimicrobial resistance (AMR). Conventional antibiotics often fail due to bacterial persistence and the physicochemical barriers of the wound milieu. Biofilm-associated extracellular polymeric substances (EPS), efflux pump activity, quorum sensing (QS), and horizontal gene transfer (HGT) collectively drive antimicrobial tolerance and resistance dissemination, turning chronic wounds into reservoirs of multidrug-resistant pathogens. Consequently, emerging wound therapies demand multifunctional strategies that modulate the wound microenvironment while interfering with resistance-associated phenotypes. Hydrogel–metal–organic framework (MOF) composites have been explored as multifunctional interfaces that combine extracellular matrix-mimetic properties, tunable porosity, stimuli-responsiveness, and controlled therapeutic delivery with the bioactive functions of MOFs. Depending on their composition and architecture, these systems may exert antimicrobial and antibiofilm effects through ionic, electrostatic, osmotic, catalytic, and oxidative mechanisms, while also influencing ROS levels, inflammation, angiogenesis, and local drug transport. However, antimicrobial activity alone does not equate to resistance modulation. Evidence for direct effects on efflux systems, resistance phenotypes, or HGT remains inconsistent across reported platforms. This review critically examines representative hydrogel–MOF systems for chronic wound applications, comparing their composition, physicochemical properties, biological functions, proposed resistance-related mechanisms, advantages, limitations, and current level of evidence. We emphasize distinguishing experimentally demonstrated resistance-modulating effects from mechanistically proposed functions, and identifying design trade-offs and evidence gaps that must be addressed to develop wound interfaces capable of both supporting tissue regeneration and improving infection control. Full article

The increasing accumulation of pharmaceutical residues in water environments poses serious threats concerning environmental safety and public health, mainly due to their tenacity, continuous bio-activity, and resistance to traditional wastewater treatment processing. Although many nano-bio/chemosensor systems have been reported for the monitoring and removal of pharmaceutical residues, the literature remains fragmented regarding their ability to integrate detection and remediation into a single platform. In this context, this review critically examines recent developments in nano-bio/chemosensor platforms for simultaneous detection and elimination of pharmaceutical effluents in wastewaters. Particular emphasis is placed on their functional integration, detection mechanisms, analytical performance, and removal pathways. This review covers the major pharmaceutical categories, including pharmaceutical drugs, antibiotics, hormones, perfluorinated compounds, and drugs of abuse and discusses nanostructured platforms based on metal organic frameworks (MOFs), nanochannel-based immunosensors, noble metal nanoparticles, layered double hydroxides, and hybrid composites. Detection approaches based on fluorescence modulation, electrochemical impedance, ionic current rectification, surface-enhanced Raman scattering (SERS), and colorimetric nanoenzyme activity could lead to extremely low detection limits. In addition, removal mechanisms such as adsorption, photocatalysis, advanced Fenton-induced oxidation processes, and nanoenzymes allow for high degradation efficiencies (>80–99%). Significant advantages for real-time monitoring and sustainable wastewater treatment can be achieved by multifunctional nanoplatforms that integrate detection and remediation capabilities. Finally, this review identifies current limitations and research gaps regarding practical application, matrix effects, regeneration, stability, scalability, and integration into real wastewater treatment systems and outlines future research directions towards more efficient and environmentally relevant multifunctional platforms. Full article

The oil and gas (O&G) industry is increasingly adopting non-metallic materials for pipelines and downhole components to mitigate corrosion, reduce maintenance costs, and improve performance in harsh service environments. Among high-performance polymers, polyether-ether-ketone (PEEK) has attracted significant attention owing to its excellent mechanical properties, thermal stability, and chemical resistance, making it a promising candidate for aggressive downhole applications. However, exposure to acids, hydrocarbons, water, CO₂, and supercritical CO₂ under high-pressure/high-temperature conditions can alter its microstructure and mechanical performance, necessitating a comprehensive understanding of its long-term behavior. This review summarizes the microstructure, properties, and current applications of PEEK in the O&G industry, including its emerging use in additive manufacturing. It further examines the fundamental mechanisms of gas and liquid diffusion, aging processes (physical, chemical, and thermal), and their effects on the morphology, thermal behavior, and mechanical properties of PEEK. By consolidating findings from studies conducted under representative O&G environments, this review identifies current knowledge gaps and future research priorities, providing guidance for the selection, qualification, and design of PEEK components for demanding oil and gas applications. Full article