A new strategy to accelerate co-deposition of plant polyphenol and amine for fabrication of antibacterial nanofiltration membranes by in-situ grown Ag nanoparticles

Facile fabrication of antibacterial membranes with human-friendly aloin for water purification

Currently, chemicals or nanoparticles are widely used for modifying membranes to improve their antifouling properties. However, the chemicals released, particularly during long-term water or wastewater filtration, are highly toxic to the environment and humans. Herein, an herb-inspired, green antibacterial membrane with exceptional sustainable antifouling properties was developed using aloin. The resultant membranes exhibited excellent bacterial inactivating efficiency because of the electrostatic interactions between the amine groups on the membrane and the bacterial cells, which contributed to cell deformation. The aloin molecules also significantly increased reactive oxygen species levels, causing oxidative damage to bacterial cells. Moreover, the functional decorative layer, which exhibited remarkable resistance to bacterial adhesion because of the abundant hydroxyl, carbonyl, and amino groups in aloin, endowed the as-prepared membranes with strong polarity, reducing bacterial adhesion and biofilm formation. When applied in a membrane bioreactor, the aloin-modified membranes demonstrated a > 27.0 % lower fouling rate than commercial microfiltration membranes. Overall, the successful fabrication strategy and material features described offer a green alternative for membrane development and provide new avenues for the design of healthcare materials such as wound dressings.

Analysis of Metal-Organic Framework and Polyamide Interfaces in Membranes for Water Treatment and Antibacterial Applications

Integrating biocidal nanoparticles (NPs) into polyamide (PA) membranes shows promise for enhancing resistance to biofouling. Incorporating techniques can tailor thin-film nanocomposite (TFN) membranes for specific water purification applications. In this study, silver-based metal-organic framework Ag-MOFs (using silver nitrate and 1,3,5-benzentricarboxylic acid as precursors) are incorporated into PA membranes via three different methods: i) incorporation, ii) dip-coating, and iii) in situ ultrasonic techniques. The characterizations, such as top-surface and cross-section scanning and transmission microscopy, reveal that the incorporation methods for the modified TFN membranes substantially control morphology and surface characteristics. For example, the in situ ultrasonically interlayered Ag-MOFs showed the largest pores (average pore diameter of 14 Å ± 0.1), resulting in the highest water permeance (water flux of 10.9 LMH/bar for Na2SO4). It also show superior antifouling and anti-biofouling performance, with a flux recovery ratio (FRR) of 94.1% in both fouling tests due to its improved surface hydrophilicity and the antibacterial properties of incorporated Ag-MOFs. Conversely, the surface-grafted dip-coated Ag-MOFs offered the highest salt rejection, attributed to its highly negatively charged surface and a dense PA network with narrow pores (average pore diameter of 10 Å ± 0.06).

Unlocking the potential of plant polyphenols: advances in extraction, antibacterial mechanisms, and future applications

Plant polyphenols are widely distributed in most higher plants, garnering significant attention from researchers due to their remarkable antioxidative, antibacterial, anticancer, and anti-radiation properties. They also offer multiple health benefits for various lifestyle-related diseases and oxidative stress. While there has been considerable research on the extraction and antibacterial application of plant polyphenols, developing a rapid and efficient extraction method remains a persistent challenge. Furthermore, the introduction of novel technologies is imperative to enhance the bioavailability of polyphenolic compounds. This comprehensive review synthesizes recent research findings pertaining to the extraction, antibacterial mechanisms, and applications of plant polyphenols. This research highlights the prevalent issues of low extraction rates of plant polyphenols and the ambiguous antibacterial mechanisms in current research. To address these challenges, this research proposes innovative directions for improving extraction technology and expanding antibacterial applications. Additionally, this review outlines promising future research avenues within the realm of plant polyphenols.

Graphical abstract

Antibacterial effect of the metal nanocomposite on Escherichia coli

Ag nanocomposites (NAs) have been found to induce irreversible harm to pathogenic bacteria, however, NAs tend to aggregate easily when used alone. These nanocomposites also show increased toxicity and their underlying antibacterial mechanism is still unknown. In short, practical applications of NA materials face the following obstacles: elucidating the mechanism of antibacterial action, reducing cytotoxicity to body cells, and enhancing antibacterial activity. This study synthesized a core-shell structured ZnFe2O4 @Cu-ZIF-8 @Ag (FUA) nanocomposite with high antibacterial activity and low cytotoxicity. The nanocomposites achieved a 99.99 % antibacterial rate against Escherichia coli (E. coli) and tetracycline-resistant E. coli (T - E. coli), in under 20 min at 100 μg/mL. The nanocomposites were able to inactivate E. coli due to the gradual release of Cu2+, Zn2+, and Ag+ ions, which synergistically form •OH from FUA in an aerobic environment. The presence of •OH has significant effects on the antibacterial activity. The released metal ions combine with •OH to cause damage to the bacterial cell wall, resulting in the leakage of electrolytes and ions. Moreover, in comparison to NA, the toxicity of FUA is considerably reduced. This study is expected to inspire the development of other silver-based nanocomposite materials for the inactivation of drug-resistant bacteria.

Preparation of polyphenol-structural colored silk fabrics with bright colors

Conventional textile dyeing relies on the use of dyes and pigments, which can cause severe environmental contamination and waste a large amount of water. Structural coloring is one of the effective ways to achieve environmentally friendly coloring of textiles. In this work, three plant polyphenols with the same o-benzenetriol structure (tannic acid (TA), gallic acid (GA), and tea polyphenol (TP)) were selected as raw materials. Three plant polyphenols can quickly form nanofilms at the gas-liquid interface through a Schiff base reaction with polyethyleneimine (PEI) under mildly alkaline conditions, which were deposited to the surface of silk fabric, allowing precise control over the thickness of film by adjusting the time, resulting in various structurally colored silk fabric. This method for creating structural colors is not substrate-specific and enables the quick production of structural colors on various textile substrates. Furthermore, the structural color silk fabric based on plant polyphenol has antibacterial performance. This textile coloring method is simple, cost-effective and environmentally friendly, providing a new approach to eco-friendly textile dyeing.

A New Strategy of Chemical Photo Grafting Metal Organic Framework to Construct NH2-UiO-66/BiOBr/PVDF Photocatalytic Membrane for Synergistic Separation and Self-Cleaning Dyes

Photocatalytic membranes are typical multifunctional membranes that have emerged in recent years. The lack of active functional groups on the surface of membranes made of inert materials such as polyvinylidene fluoride(PVDF) makes it difficult to have a stable binding interaction with photocatalysts directly. Therefore, in this study, we developed a simple method to prepare NH2-UiO-66/BiOBr/PVDF(MUB) membranes for efficient dye treatment by grafting benzophenolic acid-functionalized NH2-UiO-66 onto the surface of membranes with photocatalytic properties under visible light irradiation using benzophenolic acid with photoinitiating ability as an anchor. The structural characteristics, photocatalytic properties, antifouling properties, and reusability of the composite membranes were investigated in subsequent experiments using a series of experiments and characterizations. The results showed that the benzophenone acid grafting method was stable and the nanoparticles were not easily dislodged. The MUB composite membrane achieved a higher dye degradation efficiency (99.2%) than the pristine PVDF membrane at 62.9% within a reaction time of 180 min. In addition, the composite membranes exhibited higher permeate fluxes for both pure and mixed dyes and also demonstrated outstanding water flux recovery (>96%) after the light self-cleaning cycle operation. This combination proved to improve the performance of the membranes instead of reducing them, increasing their durability and reusability, and helping to broaden the application areas of membrane filtration technology.

Efficient oil-water emulsion treatment via novel composite membranes fabricated by CaCO3-based biomineralization and TA-Ti(IV) coating strategy

Continuous increasing discharge of industrial oily wastewater and frequent occurrence of oil spill accidents have taken heavy tolls on global environment and human health. Organic-inorganic modifications can fabricate superhydrophilic/submerged superoleophobic membranes for efficient oil-water separation/treatment though they still suffer from complex operation, non-environmental friendliness, expensive cost or uneven distribution. Herein, a new strategy regarding tannic acid (TA)-Ti(IV) coating and CaCO₃-based biomineralization through simple inkjet printing processes was proposed to modify polyvinylidene fluoride (PVDF) membrane, endowing the membrane with high hydrophilicity (water contact angle (WCA) decreased from 86.01° to 14.94°) and underwater superoleophobicity (underwater contact angle (UOCA) > 155°). The optimized TA-Ti(IV)-CaCO₃ modified membrane possessed perfect water permeation to various oil/water emulsions (e.g., 355.7 L·m^-2·h^-1 for gasoline emulsion) under gravity with superior separation efficiency (>98.8 %), leading the way in oil/water emulsion separation performance of PVDF membranes modified with polyphenolic surfaces to our knowledge. Moreover, the modified membrane displayed rather high flux recovery after eight cycles of filtration while maintaining the original excellent separation efficiency. The modification process proposed in this study is almost independent of the nature of the substrate, and meets the demand for simple, inexpensive, rapid preparation of highly hydrophilic antifouling membranes, showing abroad application prospect for oil-water emulsion separation/treatment.

Smart Nanostructured Materials for SARS-CoV-2 and Variants Prevention, Biosensing and Vaccination

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has raised great concerns about human health globally. At the current stage, prevention and vaccination are still the most efficient ways to slow down the pandemic and to treat SARS-CoV-2 in various aspects. In this review, we summarize current progress and research activities in developing smart nanostructured materials for COVID-19 prevention, sensing, and vaccination. A few established concepts to prevent the spreading of SARS-CoV-2 and the variants of concerns (VOCs) are firstly reviewed, which emphasizes the importance of smart nanostructures in cutting the virus spreading chains. In the second part, we focus our discussion on the development of stimuli-responsive nanostructures for high-performance biosensing and detection of SARS-CoV-2 and VOCs. The use of nanostructures in developing effective and reliable vaccines for SARS-CoV-2 and VOCs will be introduced in the following section. In the conclusion, we summarize the current research focus on smart nanostructured materials for SARS-CoV-2 treatment. Some existing challenges are also provided, which need continuous efforts in creating smart nanostructured materials for coronavirus biosensing, treatment, and vaccination.

Plant Polyphenol Pyrogallol and Polyamine-Based Co-Deposition for High-Efficiency Nanofiltration Membrane Preparation towards Inorganic Salt Removal

The co-deposition between polyphenols and amines has been demonstrated in order to prepare positively charged nanofiltration (NF) membranes for multivalent cation rejection in recent years; however, the low reactivities of the involved polyphenols usually cause a long co-deposition time and unsatisfactory rejection. Herein, a novel plant polyphenol (PG) was co-deposited with tetraethylenepentamine (TEPA) in a much shorter time period to prepare positively charged NF with high multivalent cation rejection membranes. The performance of the co-deposition membranes can be easily controlled by adjusting the mass ratio of PG and TEPA, reaction time, and pH value of the buffer solution. The optimal membrane, prepared under a polyphenol and polyamine mass ratio of 1:1, coating time of 2 h, and pH value of 8.0, shows a decent pure water permeability of 8.43 L m^-2 h^-1 bar^-1 while maintaining a superior 96.24% MgCl₂ rejection. More importantly, the universality of this method was corroborated by employing other amines with different molecular weights in the co-deposition. This work provides new insights for the preparation of high-performance positively charged NF membranes.

Impacts of Calcium Addition on Humic Acid Fouling and the Related Mechanism in Ultrafiltration Process for Water Treatment

Humic acid (HA) is a major natural organic pollutant widely coexisting with calcium ions (Ca²⁺) in natural water and wastewater bodies, and the coagulation-ultrafiltration process is the most typical solution for surface water treatment. However, little is known about the influences of Ca²⁺ on HA fouling in the ultrafiltration process. This study explored the roles of Ca²⁺ addition in HA fouling and the potential of Ca²⁺ addition for fouling mitigation in the coagulation-ultrafiltration process. It was found that the filtration flux of HA solution rose when Ca²⁺ concentration increased from 0 to 5.0 mM, corresponding to the reduction of the hydraulic filtration resistance. However, the proportion and contribution of each resistance component in the total hydraulic filtration resistance have different variation trends with Ca²⁺ concentration. An increase in Ca²⁺ addition (0 to 5.0 mM) weakened the role of internal blocking resistance (9.02% to 4.81%) and concentration polarization resistance (50.73% to 32.17%) in the total hydraulic resistance but enhanced membrane surface deposit resistance (33.93% to 44.32%). A series of characterizations and thermodynamic analyses consistently suggest that the enlarged particle size caused by the Ca²⁺ bridging effect was the main reason for the decreased filtration resistance of the HA solution. This work revealed the impacts of Ca²⁺ on HA fouling and demonstrated the feasibility to mitigate fouling by adding Ca²⁺ in the ultrafiltration process to treat HA pollutants.

Mechanistic insights into Ca-alginate gel-associated membrane fouling affected by ethylene diamine tetraacetic acid (EDTA)

While transparent exopolymer particles (TEP) is a major foulant, and ethylene diamine tetraacetic acid (EDTA) is a strong chelating agent frequently used for fouling mitigation in membrane-based water treatment processes, little has been known about TEP-associated membrane fouling affected by EDTA. This work was performed to investigate roles of EDTA addition in TEP (Ca-alginate gel was used as a TEP model) associated fouling. It was interestingly found that, TEP had rather high specific filtration resistance (SFR) of 2.49 × 10¹⁵ m^-1·kg^-1, and SFR of TEP solution firstly decreased and then increased rapidly with EDTA concentration increase (0-1 mM). A series of characterizations suggested that EDTA took roles in SFR of TEP solution by means of changing TEP microstructure. The rather high SFR of TEP layer can be attributed to the big chemical potential gap during filtration described by the extended Flory-Huggins lattice theory. Initial EDTA addition disintegrated TEP structure by EDTA chelating calcium in TEP, inducing reduced SFR. Continuous EDTA addition decreased solution pH, resulting into no effective chelating and accumulation of EDTA on membrane surface, increasing SFR. It was suggested that factors increasing homogeneity of TEP gel will increase SFR, and vice versa. This study revealed the thermodynamic mechanism of TEP fouling behaviors affected by EDTA, and also demonstrated the importance of EDTA dosage and pH adjustment for TEP-associated fouling control.

Impact of sulfur-impregnated biochar amendment on microbial communities and mercury methylation in contaminated sediment

S-impregnation of biochar through elemental S streaming is known to increase its sorption performance against Hg and methyl mercury (MeHg). However, the effects of %S-loading on biochar's mechanism and sorption capacities for MeHg, and its consequent impact when used as an amendment material for Hg-contaminated sediments, are poorly understood, and thus, were investigated in this work. Our results showed that a minimum sulfur loading of 1% was the most effective in reducing MeHg levels in sediments. At higher %S-loading (3-20%), the reduction in surface area, pore blockage due to unreacted sulfur particles, and presence of poorly bound sulfur species resulted in lowered effectiveness for MeHg control. Increasing S-functionalization during impregnation shifted the sorption process of MeHg from Hg-O to Hg-S in S-impregnated biochar (BCS). Our 60-day slurry experiment showed a significant reduction in pore water THg (40-70%) and MeHg (30-55%), as well as sediment MeHg (50-60%) in biochar-amended sediments. The reduction in the bioavailable Hg resulted in lowered Hg methylation, as supported by the suppression of both the Fe- and SO₄^2--reduction activities in the amended sediments. The microbial community structure in BCS-amended sediments showed a shift towards sulfur-consuming, iron-reducing, thiosulfate-oxidizing, and sulfate-reducing bacterial populations. At the genus level, the overall relative abundance of principal Hg methylators was also lower in the BCS treatment than in the unamended sediments. This study highlights the application of BCS as a promising strategy for remediation of Hg-contaminated sediments.

Preparation of tannic acid and L-cysteine functionalized magnetic composites for synergistic enrichment of N-glycopeptides followed by mass spectrometric analysis

Glycoprotein is involved in a variety of biological activities and has been linked to a number of diseases. Glycopeptide enrichment prior to mass spectrometry (MS) detection is crucial to reduce interference, improve detection efficiency, and analyze proteomics deeply and comprehensively. Here, we prepared a novel magnetic hydrophilic material combining tannic acid (TA) and L-cysteine (L-Cys) through a simple and fast procedure. Owing to the synergistic hydrophilic interaction of TA and L-Cys, the obtained adsorbent material shows excellent enrichment performance toward N-glycopeptides with low detection limit, high selectivity, and good reusability. Besides, the material can also be utilized for the enrichment of N-glycopeptides in human serum and saliva, which shows its application prospect in complex biological samples.

Thermal-controlled active sensor module using enzyme-regulated UiO-66-NH2/MnO2 fluorescence probe for total organophosphorus pesticide determination

An enzyme-regulated UiO-66-NH₂/MnO₂ fluorescence sensor, fully functionalized with spectrometric capacities, is developed for budget-friendly total organophosphorus pesticides (OPs) determination. The fluorescence probe, UiO-66-NH₂/MnO₂, is hydrothermally synthesized and morphologically examined. A specialized enzyme-catalyzed reaction, which can be gradually inhibited by OPs, is designed with participations of alkaline phosphatase (ALP) and sodium L-ascorbyl-2-phosphate (AAP). The reaction product of ascorbic acid (AA) decomposes MnO₂ and restores UiO-66-NH₂ fluorescence, establishing a relationship between OPs level and fluorescence intensity. Interactions among UiO-66-NH₂, MnO₂, OPs, and AA are clarified. Stepwise optimizations are performed to the UiO-66-NH₂/MnO₂ probe, ensuring considerable advantages as OPs affinity and fluorescence quenching behavior over rival nanomaterials. Analytical advances are magnified by fabricating an active sensor module, with self-acting thermal regulation for optimal enzyme activity. Under 4 and 20 °C environment, regulation period is less than 40 and 100 s. In total OPs determination for laboratorial and real-vegetable samples, this method exhibits uniform and log-linear responses to common species of OPs in a range as 1.0 × 10^-7~10 mg L^-1, and limit of detection is established as 8.9 × 10^-8 mg L^-1. Proposed readouts are validated with certified HPLC and recovery test. Relative errors and recovery rates are found as 2.7-6.4% and 95.8-102.6%, respectively.

Optimized production conditions and activation of biochar for effective promotion of long-chain fatty acid degradation in anaerobic digestion

Engineered biochar production and utilization in anaerobic digestion (AD) potentially overcome its limited application to the treatment of slowly degradable or inhibitory substrates. Here an attempt was made to develop an optimized biochar production procedure for use in AD to stimulate palmitic acid biodegradation via direct interspecies electron transfer (DIET). The electrical conductivity of biochar was greatly increased with an elevated pyrolysis temperature and K₂CO₃ activation, and the conductivity reached a comparable level (0.6-1.4 S/cm) to that of carbon black at 800 °C. In addition, the K₂CO₃ activation greatly improved biochar wettability. When using K₂CO₃-activated biochar produced at 800 °C, the maximum methane production rate from palmitic acid was 1.3 times that of a control without biochar addition.

Graphene Oxide-Chitosan Network on a Dialysis Cellulose Membrane for Efficient Removal of Organic Dyes

Currently, water pollution is a significant health problem for both humans and animals due to large amounts of dye-containing wastewater. Thus, polymer composite membranes (PCMs) are considered as efficient adsorption/filtration membranes that can be utilized for removing organic dyes from contaminated water/wastewater. In this study, the goal is to explore the modification of the interfacial dialysis cellulose (DC) surface through molecular interactions of an active graphene oxide-chitosan (GO-CTS) composite hydrogel (GCCH) network without the use of an external cross-linker toward an effective dye removal ability using a simple casting process and a low-cost adsorption technique, resulting in the formation of a PCM, i.e., GO/CTS/DC membrane (GCD-mems). Concomitantly, the incorporation of the GCCH network (as an active hybrid network) and DC (as a supporting material) is considered as a promising approach toward a dye-removing PCM. As a result, the GCD-mems showed that cellulose robustly interacted via the chemical bonds of the GCCH network by maintaining the three-dimensional (3D) porous layer structures, and the functional surface of the membrane was enhanced toward specific groups for an effective dye removal approach. In addition, there is a significant improvement in dye removal performance after modification of the interfacial DC surface through molecular interactions of GCCH, i.e., high adsorption capacities of cationic and anionic dye molecules on the GCD-mems, compared to the relevant GO-based adsorbents. Also, the dye flux and rejection of the GCD-mems can simultaneously remove both methylene blue and Congo red. In the adsorption, it is appropriate with the pseudo-second-order and Langmuir models corresponding to chemical adsorption and monolayer approaches, as well as physical sieving through the 3D layers of porous channels of GCD-mems during the filtration process. Moreover, the structural stability and sustainability of the PCMs are enhanced during the recycling process, and the use of ethanol in the recycling process further simplifies the process and reduces the cost of the PCMs. Thus, the GCD-mems are encouraged as potential candidates that can be applied directly in the removal of dyes from the wastewater of textile industries or selective dialysis applications.

Fundamental thermodynamic mechanisms of membrane fouling caused by transparent exopolymer particles (TEP) in water treatment

While transparent exopolymer particles (TEP) has high fouling potential, its underlying fouling mechanisms have not yet been well revealed. In current work, fouling characteristics of TEP under different Ca²⁺ concentrations (0 to 1.5 mM) were investigated. TEP quantification and filtration tests showed that TEP contents increased with Ca²⁺ concentration, while TEP's specific filtration resistance (SFR) under the influence of Ca²⁺ concentration presented a unimodal pattern. The peak of TEP's SFR reached at Ca²⁺ concentration of 1 mM when SA concentration was 0.3 g·L^-1. A series of characterizations suggested that microstructure transformation of TEP particles was the main contributor to the resistance variations of TEP solution. The optical microscope observation showed that above and below the critical Ca²⁺ concentration (1 mM when SA concentration is 0.3 g·L^-1 in this study), the formed TEP existed in the form of c-TEP (average particle size is 0.24 μm) and p-TEP (average particle size is 1.05 μm), respectively. Thermodynamic analysis showed that the adhesion ability of c-TEP (-249,989 and - 303,692 kT) was more than 19 times than that of p-TEP (-12,905 kT), which would accelerate foulant layer formation. In addition, below the critical value, the increased SFR with Ca²⁺ concentration could be explained by integrating Flory-Huggins lattice theory with the preferential intermolecular coordination. Above the critical value, the decreased SFR can be attributed to the formation of a "large-size crack structure" cake layer from the p-TEP. This study revealed fundamental mechanisms of membrane fouling caused by TEP, greatly deepening understanding of TEP fouling, and facilitating to development of effective fouling control strategies.

Graphene/g-carbon nitride (GO/g-C3N4) nanohybrids as a sensor material for the detection of methyl parathion and carbendazim

The widespread use of methyl parathion (MP) and carbendazim (CBZ) as pesticide molecules for controlling pests and protect crops has added pollution issues; excess usage of these can lead to atmospheric pollution through contaminating water and soil sources. In the present study, detection of these compounds at the trace level was achieved by employing graphene oxide (GO) and graphitic carbon nitride (g-C₃N₄) nanohybrid electrode assembly (GO/g-C₃N₄/GCE). The X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), and Atomic Force Microscopy (AFM) techniques were also used to characterize the materials developed to reveal their purity, crystal structure, and morphology. The complete voltammetric behavior of these analytes was investigated using cyclic voltammetic (CV) and square wave voltammetry (SWV) techniques. The influence of pH was studied and it was noticed that electrochemical response was the highest at pH 7.0 for MP and at pH 4.2 for CBZ. Density Functional Theory (DFT) calculations could help us to understand the adsorption behavior of MP and CBZ onto the GO and g-C₃N₄ before their degradation due to the electrochemical reactions. SWV technique was helpful in the trace level detection of MP and CBZ. Linearity plots were obtained in the range of concentration from 8.0 × 10^-8 M to 1.0 × 10^-4 M with a limit of detection 0.824 nM for MP and 1.0 × 10^-8 M to 2.5 × 10^-4 M for CBZ with the detection limit of 2.82 nM. Significance of the developed method in the field of agricultural and environmental domains was successfully investigated by monitoring MP and CBZ in water and soil samples, and the obtained results suggested the selectivity, stability, and reproducibility of the newly developed GO/g-C₃N₄/GCE electrode assembly.

Heparinized anticoagulant coatings based on polyphenol-amine inspired chemistry for blood-contacting catheters

Blood-contacting catheters occupy a vital position in modern clinical treatment including but not limited to cardiovascular diseases, but catheter-related thrombosis associated with high morbidity and mortality remains a major health concern. Hence, there is an urgent need for functionalized catheter surfaces with superior hemocompatibility that prevent protein adsorption and thrombus formation. In this work, we developed a strategy for constructing a kind of polyphenol-amine coating on the TPU surface (TLA) with tannic acid and lysine via simple dip-coating, inspired by dopamine adhesion. Based on the long-term stability and modifiable properties of TLA coatings, heparin was introduced by an amide reaction to provide anticoagulant activity (TLH). X-ray photoelectron spectroscopy and surface zeta potential measurements fully indicated the successful immobilization of heparin. Water contact angle measurements demonstrated good hydrophilicity and stability for 15 days of TLH coatings. Furthermore, the TLH coatings exhibited significant hemocompatibility and no cytotoxicity. The good antithrombotic properties of the functionalized surfaces were confirmed by an ex vivo blood circulation model. The present work is supposed to find potential clinical applications for preventing surface-induced thrombosis of blood-contacting catheters.

Antifouling catalytic mixed-matrix membranes based on polyethersulfone and composition-optimized Zn-Cu-Fe-O CWAO catalyst under dark ambient conditions

Besides photocatalysts, novel catalytic wet-air oxidation (CWAO) catalysts capable of operating under mild conditions are a potential candidate to fabricate antifouling filtration membranes. This study optimized the CWAO catalyst consisting of three metal oxide components (ZnO, CuO, and Fe₃O₄) and used it to fabricate composite membranes with PES (polyethersulfone). The catalyst was characterized by methods such as FTIR, BET, XRD, UV-Vis DRS, XPS, ESR. The activity of the catalyst and the composite membranes was tested by the Acid Yellow 42 (AY42) degradation experiments in both cases with and without hydrogen peroxide at room conditions with air aeration. The pure water fluxes of composite membranes were also investigated based on a vacuum filtration system. The major degradation pathways of AY42 by the catalyst were proposed from the DFT (Density Functional Theory) and NBO (Natural Bond Orbital) calculations. The results showed that the optimal catalyst has molar ratios of Zn, Cu, and Fe metal ions of 0.05, 0.588, and 0.362, respectively, with AY42 decomposition efficiency of 88% in 3 h. The main factors affecting the catalytic efficiency of the CWAO catalyst determined from the trapping experiment were e^- and O₂. The results from different materials characterization methods have demonstrated the successful synthesis of the catalyst with a high surface area (103.5 m²/g) and small pore diameters (∼10 nm). The AY42 degradation of composite membranes was stable over five repeated cycles with over 70% efficiency. The pure water fluxes of composite membranes have also been significantly improved and are proportional to catalyst contents.