Search Results (200)

Current work investigates the fabrication and performance of nanocomposite membranes, modified with varying concentrations of hybrid nanostructures comprising titanium nanowires coated with iron nanoparticles (TiO₂ NWs-Fe₂O₃), for the removal of Naphthol Blue Black (NBB) dye from industrial wastewater. A series of analytical tools were employed to confirm the successful modification including scanning electron microscopy and EDX analysis, porosity and hydrophilicity measurements, Fourier-transform infrared spectroscopy, and X-Ray Diffraction. The incorporation of TiO₂ NWs-Fe₂O₃ has enhanced membrane performance significantly by increasing the PWF and improving dye retention rates of nanocomposite membranes. At 0.7 g of nanostructure content, the modified membrane (M8) achieved a PWF of 93 L/m²·h and NBB dye rejection of over 98%. The flux recovery ratio (FRR) analysis disclosed improved antifouling properties, with the M8 membrane demonstrating a 73.4% FRR. This study confirms the potential of TiO₂ NWs-Fe₂O₃-modified membranes in enhancing water treatment processes, offering a promising solution for industrial wastewater treatment. These outstanding results highlight the potential of the novel PES-TiO₂ NWs-Fe₂O₃ membranes for dye removal and present adequate guidance for the modification of membrane physical properties in the field of wastewater treatment. Full article

Healthcare-associated infection, mainly through medical device-associated infection, remains a critical issue in hospital care. Bacterial adhesion, proliferation, and biofilm formation on the device surface have been considered the foremost cause of medical device-associated infection. Different means have been explored to reduce microbial attachment and proliferation, including forming a bactericidal or microbial adhesion-resistant surface layer. Fear of limited bactericidal capability if the dead microbes remained adhered to the surface has withheld the widespread use of a bactericidal surface in medical devices if it was intended for long-term use. By contrast, constructing a microbial adhesion-resistant or antifouling surface, such as a surface with zwitterionic functionality, would be more feasible for devices intended to be used for the long term. Nevertheless, a sophisticated multi-step chemical reaction process would be needed. Instead, a simple immersion method that utilized a novel mussel-inspired catechol compound with zwitterionic sulfobetaine functionality, ZDS, was explored in this investigation for the surface modification of substrates with distinctively different surface characteristics, including titanium and polyvinyl chloride. Dopamine, NaIO₄ oxidants, and chemicals that could affect ionic interactions (NaCl and polyethyleneimine) were added to the ZDS-containing immersion solution to compare their effects on modifying titanium and PVC substrates. Furthermore, a layer-by-layer immersion method, in which the substrate was first immersed in the no-ZDS-added dopamine-containing solution, followed by the ZDS-containing solution, was also attempted on the PVC substrate. By properly selecting the immersion solution formulation and additional NaIO₄ oxidation modification, the antibacterial capability of ZDS-modified substrates can be optimized without causing cytotoxicity. The maximum antibacterial percentages against S. aureus were 84.2% and 81.7% for the modified titanium and PVC substrate, respectively, and both modified surfaces did not show any cytotoxicity. Full article

As an emerging energy-saving approach, bio-inspired drag reduction technology has become a key research direction for reducing energy consumption and greenhouse gas emissions. This study introduces the latest research progress on bio-inspired microstructured surfaces in the field of underwater drag reduction, focusing on analyzing the drag reduction mechanism, preparation process, and application effect of the three major technological paths; namely, bio-inspired non-smooth surfaces, bio-inspired superhydrophobic surfaces, and bio-inspired modified coatings. Bio-inspired non-smooth surfaces can significantly reduce the wall shear stress by regulating the flow characteristics of the turbulent boundary layer through microstructure design. Bio-inspired superhydrophobic surfaces form stable gas–liquid interfaces through the construction of micro-nanostructures and reduce frictional resistance by utilizing the slip boundary effect. Bio-inspired modified coatings, on the other hand, realize the synergistic function of drag reduction and antifouling through targeted chemical modification of materials and design of micro-nanostructures. Although these technologies have made significant progress in drag reduction performance, their engineering applications still face bottlenecks such as manufacturing process complexity, gas layer stability, and durability. Future research should focus on the analysis of drag reduction mechanisms and optimization of material properties under multi-physical field coupling conditions, the development of efficient and low-cost manufacturing processes, and the enhancement of surface stability and adaptability through dynamic self-healing coatings and smart response materials. It is hoped that the latest research status of bio-inspired drag reduction technology reviewed in this study provides a theoretical basis and technical reference for the sustainable development and energy-saving design of ships and underwater vehicles. Full article

As critical interfaces bridging biological systems and electronic devices, the performance of bioelectrodes directly determines the sensitivity, selectivity, and reliability of biosensors. Recent advancements in functional nanomaterials (e.g., carbon nanomaterials, metallic nanoparticles, 2D materials) have substantially enhanced the application potential of bioelectrodes in disease detection, metabolic monitoring, and early diagnosis through strategic material selection, structural engineering, interface modification, and antifouling treatment. This review systematically examines the latest progress in nanomaterial-enabled interface design of bioelectrodes, with particular emphasis on performance enhancements in electrophysiological/electrochemical signal acquisition and multimodal sensing technologies. We comprehensively analyze cutting-edge developments in dynamic metabolic parameter monitoring for chronic disease management, as well as emerging research on flexible, high-sensitivity electrode interfaces for early disease diagnosis. Furthermore, this work focused on persistent technical challenges regarding nanomaterial biocompatibility and long-term operational stability while providing forward-looking perspectives on their translational applications in wearable medical devices and personalized health management systems. The proposed framework offers actionable guidance for researchers in this interdisciplinary field. Full article

In accordance with growing environmental pressures and the demand for sustainable industrial practices, membrane technologies have emerged as key enablers for increasing efficiency, reducing emissions, and supporting circular processes across multiple sectors. This review focuses on the integration among microalgae-based systems, offering innovative and sustainable solutions for biomass production, carbon capture, and industrial wastewater treatment. In cultivation, membrane photobioreactors (MPBRs) have demonstrated biomass productivity up to nine times greater than that of conventional systems and significant reductions in water (above 75%) and energy (approximately 0.75 kWh/m³) footprints. For carbon capture, hollow fiber membranes and hybrid configurations increase CO₂ transfer rates by up to 300%, achieving utilization efficiencies above 85%. Coupling membrane systems with industrial effluents has enabled nutrient removal efficiencies of up to 97% for nitrogen and 93% for phosphorus, contributing to environmental remediation and resource recovery. This review also highlights recent innovations, such as self-forming dynamic membranes, magnetically induced vibration systems, antifouling surface modifications, and advanced control strategies that optimize process performance and energy use. These advancements position membrane-based microalgae systems as promising platforms for carbon-neutral biorefineries and sustainable industrial operations, particularly in the oil and gas, mining, and environmental technology sectors, which are aligned with global climate goals and the UN Sustainable Development Goals (SDGs). Full article

To address the challenges of cotton cellulose materials being susceptible to environmental humidity and pollutant erosion, a strategy for constructing superhydrophobic functional coatings with biomimetic micro–nano composite structures was proposed. Through surface silanization modification, diatomite (DEM) and Fe₃O₄ nanoparticles were functionalized with octyltriethoxysilane (OTS) to prepare superhydrophobic diatomite flakes (ODEM) and OFe₃O₄ nanoparticles. Following the multi-scale composite principle, ODEM and OFe₃O₄ nanoparticles were blended and crosslinked via the hydroxyl-initiated ring-opening polymerization of epoxy resin (EP), resulting in an EP/ODEM@OFe₃O₄ composite coating with hierarchical roughness. Microstructural characterization revealed that the micrometer-scale porous structure of ODEM and the nanoscale protrusions of OFe₃O₄ form a hierarchical micro–nano topography. The special topography combined with the low surface energy property leads to a contact angle of 158°. Additionally, the narrow bandgap semiconductor characteristic of OFe₃O₄ induces the localized surface plasmon resonance effect. This enables the coating to attain 80% light absorption across the 350–2500 nm spectrum, and rapidly heat to 45.8 °C within 60 s under 0.5 sun, thereby demonstrating excellent deicing performance. This work provides a theoretical foundation for developing environmentally tolerant superhydrophobic photothermal coatings, which exhibit significant application potential in the field of anti-icing and anti-fouling. Full article

The efficient removal of emulsified oil and trace organic pollutants via forward osmosis (FO) technology remains challenging due to limited water flux and membrane fouling. In this study, a series of metal oxide-modified PES-based composite FO membranes were fabricated and systematically evaluated to compare the effects of ZnO, Al₂O₃, and CuO nanoparticles on membrane structure and separation performance. The results demonstrated that the membrane modified with 0.04 g of ZnO nanoparticles achieved optimal synergy in terms of hydrophilicity, surface charge, and pore structure. The pure water flux increased from 5.48 L·m⁻²·h⁻¹ for the pristine membrane to 18.5 L·m⁻²·h⁻¹ for the ZnO-modified membrane, exhibiting a 237.5% increase in pure water flux compared to the pristine PES membrane, an oil rejection rate exceeding 97%, and over 95% rejection of typical negatively charged trace organic pollutants such as ibuprofen and tetracycline. Moreover, the ZnO-modified membrane showed excellent antifouling performance and structural stability in various organic solvent systems. This study not only optimized the interfacial chemistry and microstructure of the FO membrane but also enhanced pollutant repellence and the self-cleaning capability through increased hydrophilicity and surface negative charge density. These findings highlight the significant potential of ZnO modification for enhancing the overall performance of FO membranes and provide an effective strategy for developing high-performance, broadly applicable FO membranes for complex water purification. Full article

Polymer membranes often face challenges of oil fouling and rapid water flux decline during the separation of oil-in-water emulsions, making them a focal point of ongoing research and development efforts. Coating PVDF membranes with a hydrogel layer equips the developed membranes with robust potential to mitigate oil fouling. However, developing a controllable thickness of a stable hydrogel layer to prevent the blocking of membrane pores remains a critical issue. In this work, atmospheric pressure low-temperature plasma was used to prepare the surface of a PVDF membrane to improve its wettability and adhesion properties for coating with a thin hydrophilic film of an AM-NaA copolymer hydrogel. The AM-NaA/PVDF membrane exhibited superhydrophilic and underwater superoleophobic properties, along with exceptional anti-crude oil-fouling characteristics and a self-cleaning function. The AM-NaA/PVDF membrane achieved high separation efficiency, exceeding 99% for various oil-in-water emulsions, with residual oil content in the permeate of less than 10 mg/L after a single-step separation. Additionally, it showed a high-water flux of 5874 L/m²·h for crude oil-in-water emulsions. The AM-NaA/PVDF membrane showed good stability and easy cleaning by water washing over multiple crude oil-in-water emulsion separation and regeneration cycles. Adding CaCl₂ destabilized emulsions by promoting oil droplet coalescence, further boosting flux. This strategy provides a practical pathway for the development of highly reusable and oil-fouling-resistant membranes for the efficient separation of emulsified oily water. Full article

Membrane technology has received great attention in the desalination and water treatment sectors over the last few decades. However, membrane fouling remains a critical issue that affects membrane performance, a phenomenon common in membrane bioreactors (MBRs). This major drawback can be overcome by the preparation of antifouling membranes using an electrospinning technique that generates a hydrophilic modification of membranes. In this study, nanocomposite polyvinylidene fluoride (PVDF) and cellulose acetate (CA) polymer was fabricated to mitigate membrane fouling. Surface and mechanical characterization of the electrospun membrane was performed to assess morphology, chemical composition, and hydrophilic/hydrophobic properties. Anti-fouling performance of the composite PVDF/CA membrane was evaluated versus a neat PVDF membrane through bench-scale experiments. The PVDF/CA nanofiber membrane displayed a more hydrophilic nature, demonstrated by a lower water contact angle (101° vs. 115°) and increased wastewater flux (190 L/m²·h. vs. 160 L/m²·h), although the composite membrane demonstrated lower tensile strength (2.0 ± 0.1 MPa vs. 1.7 ± 0.1 MPa). The new material demonstrated greater anti-fouling performance compared to the neat PVDF membrane. Results suggest that this nanofiber material shows promise as an enhanced antifouling membrane that can overcome membrane fouling limitations. Full article

This study aims to develop a robust and reproducible method for fabricating efficient ultrathin antifouling coatings on gold surfaces by leveraging hydroxylation-based surface modifications. An ultrathin antifouling coating of a monoethylene glycol silane derivative, known to reduce fouling by at least 90% on flat hydroxylated surfaces, was successfully replicated on flat gold (reducing fouling by ~75%) by hydroxylating its surface with β-mercaptoethanol. This tandem coating contains the monoethylene glycol silane layer on top of the β-mercaptoethanol on the gold. Characterization was performed using contact angle goniometry, atomic force microscopy, x-ray photoelectron spectroscopy, and antifouling measurements. The results from these techniques, consistent with the literature, confirmed the successful and reproducible application of the tandem coating. Through heterogeneities, including defects and incomplete coverage, the AFM data revealed distinct visible layers of the tandem coating. The direct application of monoethylene glycol silane onto gold resulted in superior antifouling performance (88% reduction), demonstrating that direct silylation exploits pre-existing oxygen-containing species on the gold surface for a more effective antifouling layer. These findings offer a scalable approach for engineering antifouling coatings on gold substrates, with potential applications in biosensing and implantable device antifouling technologies. Full article

Accelerated urbanization and industrialization have significantly heightened water contamination risks, posing severe threats to public health and ecological balance. Polymeric membranes stand at the forefront of addressing this challenge, revolutionizing water and wastewater treatment. These membranes adeptly remove a broad spectrum of contaminants, including organic compounds and heavy metals, thereby playing a crucial role in mitigating environmental pollution. This research delves into the sophisticated mechanisms of polymeric membranes in filtering out pollutants, with a spotlight on the enhancements brought about by nanotechnology. This includes a detailed examination of their inherent antibacterial properties, showcasing their innovative design and potential for extensive application. The study further investigates advanced techniques like electrochemical processes and membrane distillation, particularly focusing on desalination. These methods are central to the advancement of water purification, emphasizing efficiency and environmental sustainability. However, challenges such as membrane fouling pose significant hurdles, necessitating ongoing research into surface modifications and antifouling strategies. This paper offers a comparative analysis of various membrane technologies, highlighting their manufacturing complexities and efficiency benchmarks. In summation, the paper underscores the importance of continuous innovation in membrane technology, aiming to develop sustainable and effective water treatment solutions. By bridging the gap between basic science and technological advancements, this review aims to guide practitioners and researchers towards a future where clean water is universally accessible, ensuring the preservation of our ecosystems. Full article

Through the application of advanced membrane modification strategies, high-performance membranes have been developed to effectively remove organic contaminants such as toluene and xylene from wastewater. These membranes demonstrate superior antifouling resistance and long-term operational stability, offering a competitive advantage for semiconductor wastewater treatment. This study introduces a novel approach to membrane fabrication using polyvinylidene fluoride (PVDF), recognized for its cost-effectiveness and distinct antifouling properties in contaminant removal. To enhance the performance of the membrane, the solvent (DMA, DMF, NMP) that dissolves PVDF and the immersion time (30 min, 60 min, 90 min) at which phase separation occurs were identified. Additionally, the membranes were treated with polyvinyl alcohol (PVA) through multiple dip coatings to enhance their hydrophilicity before a comparative analysis was conducted. The resulting optimized membranes demonstrated high emulsion fluxes (4412 $\mathrm{L}{\mathrm{m}}^{-2}{\mathrm{h}}^{-1}{\mathrm{bar}}^{-1}$ for toluene) and achieved oil-removal efficiencies exceeding 90% when tested with various organic solvents, including toluene, cyclohexane, xylene, benzene, and chloroform. The resulting optimized membranes prove to be a reliable means of producing clean water and of efficiently separating organic contaminants from wastewater. Showcasing remarkable antifouling capabilities and suitability for repeated use without significant efficiency loss, this solution effectively addresses cost and fouling challenges, presenting it as a sustainable and efficient wastewater treatment method for the semiconductor industry. Full article

Laser surface texturing (LST) is a versatile method for enhancing material surface properties, offering high precision and flexibility for surface modification. This review comprehensively examines the application of laser texturing technology for surface protection and functional regulation of aluminum alloys, focusing on wettability, anti-icing, corrosion resistance, and wear resistance. It highlights recent progress in laser surface patterning techniques, describing the principles and attributes of methods such as direct laser writing, laser interference patterning, and laser shock treatment. The influence of laser intensity, scanning velocity, and texture spacing on surface topography is discussed thoroughly. Mechanisms of wettability control via laser surface texturing are summarized, emphasizing the key factors required to achieve superhydrophobic or hydrophilic properties through texture design. Advancements in enhancing anti-icing, anti-frost, anti-fouling, and anti-corrosion properties through multi-scale textures and their synergistic effects with functional coatings are analyzed. Additionally, the enhancement of wear resistance and friction performance under both dry and lubricated conditions is reviewed, with a focus on how the geometry and arrangement of textures affect the coefficient of friction and wear rate. Finally, the paper addresses challenges and future directions, including process optimization, scalability, and the integration of LST with advanced coatings to maximize its potential in aluminum alloy applications. Full article

Waterborne polymer coated controlled release fertilizers (CRFs) are highly valued for their potential to enhance nitrogen use efficiency (NUE) and reduce fertilization labor costs. However, their application in crops with long growth periods, such as rice and maize, is limited by inadequate coating strength and suboptimal hydrophobicity. Inspired by the hydrophobic and anti-fouling structure of lotus leaf cuticles, this study biomimetically modified waterborne polyacrylate-coated urea (PACU) using natural bio-wax including rice bran wax (RBW), candelilla wax (CAW), bees wax (BW) and carnauba wax (CW), along with paraffin wax (PW) as a control. The modifications significantly extended nutrient release duration by 22 d compared to unmodified PACU, with CW providing the longest duration, followed by CAW, BW, RBW, and PW. Additionally, the modification of BW, CAW, and CW exhibited superior hydrophobicity and affinity to polyacrylate coatings, while the inferior hardness and toughness of PW compromised its controlled release performance. Field trials demonstrated that CW-modified CRFs effectively controlled nutrient release in rice and maize, resulting in a 7.2% increase in rice yield and a 37.9% increase in maize yield, as well as an 18.7% improvement in NUE compared to conventional fertilizers. These findings offered a novel approach for hydrophobic modification of waterborne polymer coatings, thereby enhancing the performance and applicability of waterborne polymer coated CRFs in long-season crops. Full article

Fouling, particularly from organic fouling and biofouling, poses a significant challenge in the RO/NF treatment of marginal waters, especially wastewater. Part 1 of this review detailed LMWOC fouling mechanisms. Part 2 focuses on countermeasures and applications. Effective fouling prevention relies on pretreatment, early detection, cleaning, optimized operation, and in situ membrane modification. Accurate fouling prediction is crucial. Preliminary tests using flat-sheet membranes or small-diameter modules are recommended. Currently, no specific fouling index exists for LMWOC fouling. Hydrophobic membranes, such as polyamide, are proposed as alternatives to the standard silt density index (SDI) filter. Once LMWOC fouling potential is assessed, suitable pretreatment methods can be implemented. These include adsorbents, specialized water filters, oxidative decomposition, and antifoulants. In situations where pretreatment is impractical, alternative strategies like high pH operation might be considered. Membrane cleaning becomes necessary upon fouling; however, standard cleaning often fails to fully restore the original flow. Specialized CIP chemicals, including organic solvent-based and oxidative agents, are required. Conversely, LMWOC fouling typically leads to a stabilized flow rate reduction rather than a continuous decline. Aggressive cleaning may be avoided if the resulting operating pressure increase is acceptable. When a significant flow rate drop occurs and LMWOC fouling is suspected, analysis of the fouled membrane is necessary for identification. Standard FT-IR often fails to detect LMWOCs. Solvent extraction followed by GC-MS is required. Pyrolysis GC-MS, which eliminates the extraction step, shows promise. The review concludes by examining how LMWOCs can be strategically utilized to enhance membrane rejection and restore deteriorated membranes. Full article