Search Results (130)

Conventional polydimethylsiloxane (PDMS)-based antifouling coatings, despite their inherent fouling-release capability, exhibit critically insufficient antifouling performance under static seawater conditions. Inspired by the synergistic physical–chemical defense strategy of sessile marine organisms, specifically sea anemones, which combine a physical mucus barrier with antimicrobial peptide secretion, the present work develops a multi-mechanism hybrid coating—designated as sea anemone-inspired fluorosilicone polyurethane—that integrates low-surface-energy physical antifouling and cationic antibacterial chemical antifouling. This coating system is constructed from silicone polyurethane (PDMS-PU), a cationic antibacterial moiety (PDMS-N⁺), and fluorinated functional monomers. Through systematic compositional optimization, an optimal formulation (P-4) is identified, which achieves a fracture elongation of 78.19%, a normal adhesion strength of approximately 2.5 MPa, a water contact angle of 120°, and a surface energy of 12.86 mN/m. Notably, its antibacterial rates against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) exceed 95%. The resultant coating uniquely synergizes low surface energy, potent antibacterial activity, excellent mechanical properties, and thermal stability, thereby enabling long-term and stable antifouling performance in static seawater environments. This work provides a crucial technological foundation for the engineering application and industrialization of green, durable marine antifouling coatings. Full article

High-salinity waters, including seawater, brines, and saline radioactive effluents, contain recoverable uranium or require uranium removal, but their complex chemistry complicates both capture and regeneration. Under seawater-relevant conditions, U(VI) occurs mainly as uranyl carbonate complexes and ternary uranyl carbonate complexes containing Ca²⁺ or Mg²⁺ rather than as free UO₂²⁺. Selective separation therefore depends on coupled transport, hydration-shell reorganization, carbonate displacement, and interfacial coordination. Conventional sorbents largely optimize binding strength and adsorption capacity, often at the expense of harsh stripping and secondary waste. This review frames thermoresponsive uranium separation as a coupled aqueous-speciation, interfacial-state, and process-design problem. It examines how LCST and UCST transitions, polymer-brush reorganization, hydration-layer reconstruction, pore gating, and localized photothermal heating regulate access to binding sites and release pathways. Polymer brushes, hydrogels and microgels, membranes and nanochannels, ion-imprinted magnetic composites, and MXene-based hybrids are critically compared using cycle-level criteria, including U/V selectivity, switching time, regeneration demand, energy input, fouling resistance, material loss, synthesis reproducibility, and environmental performance. Particular emphasis is placed on distinguishing genuine structural gating from the generic effects of temperature on diffusion, ligand exchange, and adsorption equilibria. Current evidence supports the feasibility of programmable capture–release interfaces but remains limited by matrix-dependent transition windows, incomplete mechanistic attribution, scarce quantitative energy and temperature-gradient data, short cycling tests, and limited device-scale validation. Progress will require standardized testing in realistic saline matrices and complete capture–release mass and energy balances rather than evaluation by maximum adsorption capacity alone. Full article

High-performance polyethersulfone (PES) ultrafiltration membranes integrating antibacterial activity and antifouling performance were fabricated via the in situ construction of bimetallic polyphenol networks (BMPNs) throughout the membrane architecture. Tannic acid (TA) functioned as a multifunctional molecular bridge, functionalizing silver metal–organic frameworks (Ag-MOFs) to yield hydrophilic T-Ag-MOFs and chelating Fe³⁺ ions from the coagulation bath to form a polyphenol network during phase inversion. T-Ag-MOF incorporation generated asymmetric morphologies featuring highly porous surfaces and sponge-like cross-sections, improving pure water permeability, mechanical integrity, and bovine serum albumin (BSA) rejection. TA-mediated functionalization increased hydrophilicity, imparted a negative surface charge, suppressed nonspecific protein adhesion, and enhanced flux recovery with low irreversible fouling. At an optimal loading of 0.4 wt%, the resultant T-Ag-MOF/Fe³⁺/PES composite membrane achieved a pure water permeability of 593.4 L m⁻² h⁻¹ bar⁻¹—1.77-fold higher than that of the pristine PES control—while sustaining a BSA rejection of 96.5%. Notably, interfacial compatibility between the T-Ag-MOFs and PES matrix was enhanced, facilitating strong, covalent-like filler–matrix adhesion. Moreover, the composite membrane delivered synergistic multifunctionality, including exceptional long-term aqueous stability, precisely tuned Ag⁺ release kinetics, and potent antibacterial activity, as evidenced by negligible uncontrolled ion leaching and a lack of structural degradation under prolonged hydration. Full article

Micro-nanobubbles (MNBs) aeration has been widely reported as an effective approach for membrane fouling mitigation. However, their optimal operation in polymeric hollow fiber membrane (HFM) systems remains unclear. In this study, the antifouling performance of MNB-assisted ultrafiltration was systematically investigated using a PVDF-HFM, with particular emphasis on release pressure and intermittent aeration strategy. Increasing the release pressure to 0.60 MPa produced smaller and more concentrated bubbles, significantly alleviating membrane fouling. A distinct intermittent-aeration window was observed, in which a 15 min interval achieved the best overall performance, with a rejection efficiency of 75% and a cleaning efficiency of 93%, approaching that of continuous aeration. Longer intervals resulted in rapid deterioration in fouling control, indicating insufficient bubble replenishment. Compared with continuous operation, the optimized intermittent mode maintained comparable membrane performance while reducing energy consumption by approximately 50%, demonstrating a clear advantage in energy efficiency. Importantly, the optimal intermittent interval for PVDF-HFM (15 min) differs from that reported for ceramic membranes (30 min), highlighting that the performance of intermittent MNB aeration is not universal but strongly dependent on membrane properties. This shift in optimal interval is attributed to differences in surface wettability, structural flexibility, and local hydrodynamic conditions, which collectively influence bubble retention, interfacial shielding, and foulant detachment. Full article

Microfluidic technologies are increasingly used as upstream structuring tools in the development of edible films and coatings. This review examines how flow-focusing, T-junction, co-flow, step-emulsification, and related microfluidic platforms generate emulsions, double emulsions, hydrogel microparticles, and multicompartment carriers that are relevant to coating design. Rather than treating microfluidics as an end in itself, the review evaluates how microfluidically generated structures influence carrier protection, matrix compatibility, controlled release, and the final functionality of edible films and coatings. Particular attention is paid to whether carrier architecture survives matrix incorporation, deposition, drying, and end use, because these downstream steps determine whether structural advantages translate into barrier, mechanical, optical, and preservation-related performance. The review also discusses the principal factors that currently limit industrial implementation, including throughput, fouling, sanitation, thermoplastic manufacturing, bonding, and integration into hygienic food-processing environments. Overall, microfluidics offers a highly controlled route for mechanism-oriented formulation development, but its practical value for edible coatings depends on whether this structural control can be translated into robust, scalable, and food-compliant manufacturing routes. Full article

Biofouling is an issue of global significance that impairs marine infrastructure, causes increased fuel consumption and greenhouse gas emissions, and threatens biodiversity. Since the year 2000, self-polishing copolymer (SPC) coatings and fouling release coatings (FRCs) dominate the fouling protection coatings market. SPC technology is based on the controlled release of biocides using a mixture of acrylic and natural binders as a delivery system. FRC technology is based on PDMS providing surface properties that resist attachment of fouling organisms. FRCs often contain surface modifying agents, such as free silicone oils, to tune the physicochemical properties of the surface. However, the long-term efficacy of these agents and their migration and distribution in PDMS-based coatings have not been well studied. In this study, we employed time-of-flight secondary ion mass spectrometry (ToF-SIMS) combined with multivariate analysis to examine the distribution of silicone oils as a function of exposure to artificial seawater (ASW). The results show that pure PDMS-based coatings allow uniform distribution of silicone oils with robust behavior upon ASW exposure. In contrast, epoxy–PDMS-based coatings displayed phase separation of the oils, which strongly altered their surface chemistry. Our findings suggest that the modification of mobile oils is critical to the performance of marine antifouling coatings. Furthermore, the presence of other ingredients of commercial coating formulations strongly affected the distribution of mobile oils. This study lays the foundation for future systematic research aimed at developing predictive models to optimize fouling protection coatings for the marine industry. Full article

While membrane technologies are critical for preventing microplastics (MPs) release into aquatic ecosystems, MPs-induced fouling remains a persistent bottleneck, necessitating energy-intensive cleaning strategies that introduce their own environmental burdens. This study presents a systematic life cycle assessment (LCA) of fouling mitigation strategies, rigorously comparing hydraulic forward flushing and nitrogen (N₂) gas scouring across both unmodified and plasma-modified (acrylic acid, cyclopropylamine, and hexamethyldisiloxane) polysulfone membranes. Results reveal a stark divergence between operational performance and environmental sustainability. Baseline operations and the hydraulic flushing of unmodified membranes have environmentally costly global warming potential (GWP) ~150 kg CO₂-eq/m³), driven primarily by high electricity consumption and frequent membrane replacement. Conversely, cyclopropylamine (CPAm) plasma-modified membranes emerging as the optimal strategy, reducing global warming potential to 68 kg CO₂-eq/m³ and cutting electricity demand by 44% through superior fouling resistance. Crucially, the study uncovers a significant trade-off regarding gas scouring: While it achieves the highest technical performance (minimal flux decline of 0.33% h⁻¹), the upstream burdens of N₂ supply increased environmental impacts by over 100% across all categories. These findings challenge the assumption that maximum fouling control equates to sustainability, suggesting that surface engineering via plasma modification, rather than aggressive physical cleaning, offers the most viable pathway for sustainable MPs remediation. Full article

Wine alcoholic fermentation occurs in a dynamic biochemical environment where interactions between the vessel and the product can cause inorganic and organic species to migrate into the fermenting must or wine. At low pH and with rising ethanol levels, fermentation tanks made of stainless steel, concrete or cementitious materials, ceramics, or polymers exhibit material-specific behaviors that may promote the release of toxic trace elements or alter technologically important ions. These changes can affect yeast physiology, fermentation kinetics, and matrix stability, directly impacting wine safety and quality. They may also influence the evolution of key fermentation metabolites and phenolic constituents, thereby affecting process performance, color development, oxidative stability, and other quality-related attributes. This review synthesizes current evidence on migration mechanisms and examines how vessel composition shapes the chemical and microbiological profile of fermentation. It also critically evaluates biosensor technologies—covering both biorecognition elements and signal-transduction strategies—and assesses the transition from laboratory prototypes to in situ or at-line implementations capable of detecting both migration-related events and process-relevant compositional changes with operational value for HACCP-based control. Electrochemical, optical, bienzymatic, and nanozyme-enabled platforms are discussed in terms of selectivity, matrix compatibility, and long-term functional stability under polyphenol and protein interference, CO₂ variability, fouling and biofouling, and calibration drift. Particular attention is given to analytes associated with vessel-derived migrants and to biosensor targets related to fermentation metabolites and phenolic indicators, which support dynamic process monitoring and quality-focused decision making. Considering regulatory compliance requirements across the EU, US, and Asia, we propose a practical pathway for integrating biosensors into HACCP monitoring by treating vessel–product interactions as critical control points, while laboratory reference methods remain essential for verification and compliance documentation. Full article

Ultrapure water (UPW) distribution loops must deliver stable hydraulics while limiting contamination from polymer piping. This study integrates computational fluid dynamics (CFD) with systematic pipe autopsy to examine contaminant behavior in a pilot-scale UPW loop constructed using chlorinated polyvinyl chloride (CPVC) and polyvinylidene fluoride (PVDF) and operated under identical conditions. CFD predicted nearly identical loop-scale velocity, pressure, and temperature fields for both materials, and identified low-shear recirculation at elbows and downstream tees as zones of elevated particle residence. Lagrangian particle tracking (0.05 μm, no-sticking) showed rapid breakthrough and complete flushing within 13 min, providing a hydraulic susceptibility map for transient retention. After eight months of operation, 17 sections were inspected endoscopically and leached at 60 °C. CPVC exhibited yellow–brown discoloration and highly heterogeneous total organic carbon (TOC) release with hot spots of 16–18 mg·L⁻¹, whereas PVDF showed low, spatially uniform TOC (0.4–2.3 mg·L⁻¹) and minimal fouling; inorganic ions remained at sub-mg·L⁻¹ levels for both materials. Overall, geometry governs where contamination can accumulate, while material properties control its magnitude and persistence, with PVDF providing greater resistance to long-term organic contamination than CPVC. Full article

The Zhundong coalfield in Xinjiang contains vast reserves and is a crucial source of thermal coal. However, the Zhundong coal has a high content of alkali and alkaline earth metals, which makes it prone to ash deposition and slagging in boilers, thereby limiting its large-scale utilization. Fluidized-bed preheating is an emerging clean combustion technology that can reduce the slagging and fouling risks associated with high-alkali coal by modifying its fuel properties. This study employs circulating fluidized-bed preheating technology to treat high-alkali coal, with a focus on investigating the effect of the preheated air equivalence ratio on fuel preheating modification. Through microscopic characterization of both the raw coal and preheated char, the release and transformation behaviors of elements and substances during the preheating process are revealed. The results demonstrate that fluidized preheating promotes alkali metal precipitation, and increasing the preheated air equivalence ratio (λ_Pr) enhances gas production and elemental release, with a volatile fraction mass conversion of up to 84.57%. As the λ_Pr value increased from 0.28 to 0.40, the average temperature in the preheater riser increased from 904 °C to 968 °C. Compared to the raw coal, the specific surface area of the preheated char was enhanced by a factor of 3.6 to 9.1 times, with a more developed pore structure and less graphitization, thus enhancing the surface reactivity of the preheated char. The increase in λ_Pr also facilitated the conversion from pyrrolic nitrogen to pyridinic nitrogen, thus improving combustion performance and facilitating subsequent nitrogen removal. These findings provide essential data support for advancing the understanding of preheating characteristics in high-alkali coal and for promoting the development of efficient and clean combustion technologies tailored for high-alkali coal. Full article

Heavy metals released from industrial effluents accumulate in the human body through the ecosystem, causing several health disorders. This study investigated the removal of cadmium (Cd²⁺) using Micellar-Enhanced Ultrafiltration (MEUF). This study employed sodium dodecyl sulfate (SDS) and flat-sheet polyethersulfone (PES) ultrafiltration membranes to separate Cd²⁺ ions from lab-simulated water. The experiments involved examining the removal efficiency of membranes without SDS usage, optimizing SDS concentration for Cd²⁺ removal, and evaluating the long-term membrane performance. Other parameters include analyzing the removal percentage of varying Cd²⁺ at constant SDS dosage, examining the effect of pH, and electrolyte concentrations on the removal of Cd²⁺. Several analytical characterizations were performed, such as FT-IR, and SEM. The FTIR confirms the aromatic C-H group at 620–867 cm⁻¹, the sulfone group at 1100–1200 cm⁻¹, and the ether group at 1230–1270 cm⁻¹ and the SEM analysis indicates no significant fouling, which aligns with the stable flux observed over time. The result showed that the optimum SDS concentration for Cd²⁺ removal was 1 Critical Micellar Concentration (CMC), achieving over 99% removal. The presence of an electrolyte decreased Cd²⁺ removal efficiency, while the pH (3 to 9) had no effect on removal. Our findings suggest that the SDS-aided ultrafiltration process is suitable for eliminating Cd²⁺ from wastewater. Full article

Background: Copper nanoparticles (CuNPs) are promising antibacterial agents, but instability and heterogeneity in ‘green’ routes limit translation. Methods: We developed a one-step synthesis in which pre-polymerized polycatechin acts as both reductant and capping agent to form copper–polycatechin core–shell nanoparticles (Cu@polycat). Physicochemical properties (TEM/DLS/XRD/FTIR/ζ), colloidal stability (pH, salt, serum), ion release, and antibacterial activity against planktonic and biofilm E. coli/S. aureus were evaluated. Results: Cu@polycat featured a ~21.5 nm metallic core and ~45 nm hydrodynamic diameter (shell ≈ 12 nm, estimated from TEM–DLS) with ζ ≈ −34 mV, conferring high stability across physiological conditions. Cu@polycat outperformed uncoated CuNPs, displaying 8-fold lower MICs and rapid bactericidal kinetics (>5-log10 in 6–8 h). Synergy between the copper core and polycatechin corona was confirmed (FICI ≈ 0.08). Cu@polycat inhibited biofilm formation by >80% and reduced viable counts in 24 h mature biofilms by ≥3-log10, whereas ampicillin was ineffective under the same biofilm conditions. Conclusions: A polycatechin-based green route furnishes a stable, synergistic nano-antibacterial platform with potent anti-biofilm activity, supporting development for wound-care and anti-fouling device coatings. Full article

Biofouling is the colonization and attachment of sessile organisms on submerged surfaces, whether natural or artificial. The presence of these communities compromises the structural integrity, operational efficiency, and durability of coastal structures, resulting in high economic and environmental costs, especially when conventional removal methods involve the use of toxic biocides. In this context, this article aimed to evaluate the scientific productivity of the literature related to sustainable antifouling strategies, with an emphasis on technologically and environmentally sustainable solutions, through a bibliometric analysis. We analyzed 160 research articles and 90 patents published between 2004 and 2024. It was observed that, since 2019, there has been an increase in publications about biofouling solutions, with a notable emphasis on China’s leadership in both scientific production and patent filings. This topic has also attracted extensive international collaboration. The most promising strategies for controlling marine biofouling involve a combination of physical, chemical, and biological methods, integrated with sustainable coatings. The growing demand for low-environmental-impact solutions has driven the development of safer, more effective, and economically viable antifouling technologies. Therefore, the integration of traditional techniques with advances in biotechnology represents a strategic path to mitigating the impacts of biofouling in marine environments. Full article

Industrial processes like farming, food processing, petroleum refinery, and leather manufacturing produce a lot of high-salinity wastewater. This wastewater presents serious environmental risks, such as soil degradation, eutrophication, and water salinization, if it is released without adequate treatment. The sources and features of high-salinity wastewater are outlined in this review, along with the main methods for removing organic pollutants, such as physicochemical, biological, and combined treatment approaches. Membrane separation, coagulation–flocculation, and advanced oxidation processes are the primary physicochemical techniques. Anaerobic and aerobic technologies are the two categories into which biological treatments fall. Physicochemical–biological combinations and the fusion of several physicochemical techniques are examples of integrated technologies. In order to achieve sustainable and effective treatment and resource recovery of high-salinity wastewater, this review compares the effectiveness and drawbacks of each method and recommends that future research concentrate on the development of salt-tolerant catalysts, anti-fouling membrane materials, halophilic microbial consortia, and optimized hybrid treatment systems. Full article

Biofouling presents a major challenge for maritime industries, leading to the widespread use of copper-based biocidal coatings that, while effective, release harmful substances into marine environments. Biocide-free alternatives, such as silicone-based, hydrogel, and natural product-derived coatings, offer more sustainable solutions. This systematic review and meta-analysis assesses the functional, economic, and environmental performance of both coating types using PRISMA guidelines and literature from Scopus and ISI Web of Knowledge (2003–2025). Data from experimental, field, and modeling studies were synthesized, covering fouling intensity, coating durability, toxicity, cost-effectiveness, and regulatory compliance. Biocidal coatings generally performed better short-term, but biocide-free options showed comparable efficacy in some cases and clear environmental benefits. Although initial costs for biocide-free coatings are higher, they may yield savings over time. The meta-analysis found no significant differences in fouling or hydrodynamic performance, though quantitative evidence is limited. Research gaps remain, particularly in long-term studies, highlighting the need for standardized testing and lifecycle assessments to guide sustainable antifouling practices. The outcome of the review also showed that some evidence was excluded due to being in non-indexed sources. This highlights the importance of combining systematic and traditional review methods to ensure a more comprehensive assessment. Full article