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This research evolves into a comparative study of three different phenolic composites as coatings for rigid contact lenses, with a particular emphasis on enhancing their antifouling properties and hydrophobicity. The primary layer, comprised of diverse phenolic compounds, serves as a sturdy foundation. An exclusive secondary layer, featuring synthetic peptoids, is introduced to further minimize biofouling. Validated through X-ray photoelectron spectroscopy, the surface analysis confirms the successful integration of the polyphenolic layers and the subsequent grafting of peptoids onto the lens surface. The efficacy of the proposed coatings is substantiated through protein adsorption tests, providing definitive evidence of their antifouling capabilities. This research employs a nuanced assessment of coating performance, utilizing the quantification of fluorescence intensity to gauge effectiveness. Additionally, contact angle measurements offer insights into wettability and surface characteristics, contributing to a comprehensive understanding of the coatings practicality.

Cotton gauze (CG) is the most commonly used primary wound dressing to protect wounds from the external environment. However, it is highly susceptible to fouling due to the adhesion of bacteria present on the wound surface. Bacterial colonization of the dressing is detrimental as it aids in wound infection and delays wound healing. To mitigate this issue, the objective of this study was to transform the inert CG into a fouling-resistant wound dressing that can actively resist bacterial adhesion and also prevent biofilm formation on the surface of cotton. In this work, a facile method of modifying commercial CG using oxidized dextran (Odex) was developed. Odex was derived from dextran via periodate oxidation reaction and then coated over the CG using mussel-inspired chemistry. The resultant Odex-modified CG demonstrated a substantial reduction in bacterial adhesion after 4 h of incubation in bacterial suspension. The modified gauze suppressed biofilm formation, achieving ~83% reduction in viable bacterial count as compared to unmodified CG after 48 h of incubation in the bacterial suspension. In addition, the modified CG also showed good breathability, wettability and moisture retention properties. The results suggest a promising approach of transforming inert CG into a potential fouling-resistant wound dressing for the management of wound infections. [ABSTRACT FROM AUTHOR]

The resuscitation of bacteria through biofilms presents a critical challenge in controlling microbial pathogenesis and addressing antimicrobial resistance. Continuous antibiofilm activity, particularly on frequently contacted surfaces, is therefore critical. In this study, a scalable is introduced, one‐step fabrication of Fe2O3/AgBr nanoimprints using a polymerizable sol–gel (PSG) approach to create functional nanostructured thin films with strong antimicrobial properties. Fe2O3, a visible‐light photocatalyst, is coupled with AgBr, a photosensitizer and dark‐active antimicrobial, forming a heterojunction that demonstrated potent antibacterial activity against Escherichia coli and Pseudomonas putida under both dark and light conditions. The heterojunctions exhibit significant biofilm inhibition in the dark, particularly against the robust biofilm‐forming P. putida, while visible light irradiation ensures complete biofilm clearance. These surfaces also achieve optimal reactive oxygen species (ROS) production, selectively targeting bacteria without compromising the integrity of mammalian cells. The biocompatibility is confirmed through MTT, TBARS, and apoptosis assays, demonstrating the non‐cytotoxic nature of the substrates. Moreover, the surfaces enable cell patterning and recovery of mammalian cells from microbial contamination, highlighting their potential in creating bacterial‐free environments for cell culture. This innovative method offers a promising route to next‐generation, self‐cleaning antimicrobial coatings, combining continuous biofilm inhibition with excellent biocompatibility and scalability. [ABSTRACT FROM AUTHOR]

Amphiphilic polymer systems have been demonstrated to be an effective and environmentally friendly approach to combat the challenges of biofouling, especially in the real ocean environment. A variety of polymer compositions containing fluorophilic perfluoropolyether (PFPE) urethane dimethacrylate and zwitterionic carboxybetaine methacrylate (CBMA) are in situ copolymerized across a broad concentration range and anchored to chemically functionalized substrates by grafting‐through polymerization. Dynamic accumulation assays with the marine diatom Navicula perminuta and the marine bacterium Cobetia marina revealed an enhanced antifouling performance in most of the amphiphilic polymer mixtures when zwitterionic units are combined with hydrophobic PFPE compounds. It is noticed that the resulting polymer networks still possess enough orientational freedom to quickly rearrange in the presence of water. It is further observed that several of the very hydrophilic formulations and some of the moderately hydrophobic formulations exhibit low fouling against the marine fouling organisms Navicula perminuta and Cobetia marina. This correlated with increased surface roughness and the ability for underwater rearrangement. Furthermore, it is discussed whether the probability that highly hydrated hydrogels, which appear sponge‐like, may create a diffuse interphase which promotes the incorporation of silt. Latter is counteracted by the hydrophobic PFPE building blocks in the amphiphilic coatings. [ABSTRACT FROM AUTHOR]

In recent years, slippery liquid-infused porous surfaces (SLIPSs) have gained significant attention in antifouling applications. However, their slippery performance often deteriorates in dynamic environments, limiting their service life. TC4 titanium alloy, commonly used in hulls and propellers, is prone to biofouling. SLIPSs have gained significant attention in antifouling applications. However, their slippery performance often deteriorates in dynamic environments, limiting their service life. To address these issues, a novel slippery liquid-infused surface (STASL) was developed on TC4 through the integration of hydroxyl end-blocked dimethylsiloxane (OH-PDMS), a silane coupling agent (KH550), and nano-titanium dioxide loaded with silver particles (TiO2-Ag, anatase) and silicone oil, thereby ensuring stable performance in both dynamic and static conditions. The as-prepared surfaces exhibited excellent sliding capabilities for water, acidic, alkaline, and saline droplets, achieving speeds of up to 2.859 cm/s. Notably, the STASL demonstrated superior oil retention and slippery stability compared to SLIPS, particularly at increased rotational speeds. With remarkable self-cleaning properties, the STASL significantly reduced the adhesion of proteins (50.0%), bacteria (77.8%), and algae (78.8%) compared to the titanium alloy. With these outstanding properties, the STASL has emerged as a promising solution for mitigating marine biofouling and corrosion on titanium alloys. [ABSTRACT FROM AUTHOR]

Lubricant‐infused organo‐gels with low surface energy solvents represent an environment‐friendly lubricating material, while the poor mechanical performance incapacitates them to harsh and intricate service conditions. To address this challenge, a simple yet highly effective strategy to prepare strong, smart, and slippery organo‐gels by glassifying the polymer network is reported. As a proof of concept, appropriate amounts of rigid solvophobic poly(phenyl methacrylate) (PPMA) units are integrated into a solvophilic poly(cyclohexyl acrylate) (PCHA) network infiltrated with lubricant. Upon forming bicontinuous phase‐separated structures, the rigid solvent‐free PPMA segments stay in glassy states, serving as a load‐bearing phase to toughen the materials effectively. Meanwhile, the soft PCHA phase maintains lubricity and extensibility by holding a substantial amount of lubricant. Owing to the synergistic effect, the gels manifest glass‐like mechanical performance with high rigidity (46.6 MPa), strength (7.7 MPa), and toughness (23.7 kJ m−2). Moreover, the materials exhibit high thermo‐sensitivity with the elastic modulus reversibly decreasing from 46.6 MPa at 20 °C to 0.23 MPa at 50 °C, endowing the gels with shape‐memory properties. Furthermore, the organo‐gels display satisfactory anti‐adhesiveness to various foreign matters. Taken together, the work represents a facile and universal strategy to reinforce organo‐gels, thereby adapting them to various applications. [ABSTRACT FROM AUTHOR]

Marine biofouling, which is one of the technical challenges hindering the growth of the marine economy, has been controlled using cuprous oxide (Cu2O) nanoparticles due to the exceptional antifouling properties of Cu(I) ions. However, Cu2O nanoparticles have encountered bottlenecks due to explosive releases of Cu+ ions, high toxicity at elevated doses, and long‐term instability. Here, we present a novel method called Redox Concomitant Formation (RCF) for fabricating a hierarchical Cu(I) metal–organic framework polypyrrole (Cu(I)−MOF/PPy) composite. This method enables in situ phase transition via successive redox reactions that change the chemical valence state and coordination mode of Cu(II)−MOF, resulting in a new structure of Cu(I)−MOF while creating a PPy layer surrounded by the hierarchical structure. Owing to the steady release of Cu+ ions from the Cu(I) sites and photothermal properties of PPy, Cu(I)−MOF/PPy exhibits superior and broad‐spectrum resistance to marine bacteria, algae, and surface‐adhered biofilms in complex biological environments, as well as long‐term stability, resulting in 100 % eradication efficiency under solar‐driven heating. Mechanistic insights into successive structural redox reactions and formation using the RCF method are provided in detail, enabling the fabrication of novel MOFs with the desired composition and structure for a wide range of potential applications. [ABSTRACT FROM AUTHOR]

Surface-based biosensors have proven to be of particular interest in the monitoring of human pathogens by means of their distinct nucleic acid sequences. Genosensors rely on targeted gene/DNA probe hybridization at the surface of a physical transducer and have been exploited for their high specificity and physicochemical stability. Unfortunately, these sensing materials still face limitations impeding their use in current diagnostic techniques. Most of their shortcomings arise from their suboptimal surface properties, including low hybridization density, inadequate probe orientation, and biofouling. Herein, we describe and compare two functionalization methodologies to immobilize DNA probes on a glass substrate via a thermoresponsive polymer in order to produce genosensors with improved properties. The first methodology relies on the use of a silanization step, followed by PET-RAFT of NIPAM monomers on the coated surface, while the second relies on vinyl sulfone modifications of the substrate, to which the pre-synthetized PNIPAM was grafted to. The functionalized substrates were fully characterized by means of X-ray photoelectron spectroscopy for their surface atomic content, fluorescence assay for their DNA hybridization density, and water contact angle measurements for their thermoresponsive behavior. The antifouling properties were evaluated by fluorescence microscopy. Both immobilization methodologies hold the potential to be applied to the engineering of DNA biosensors with a variety of polymers and other metal oxide surfaces. [ABSTRACT FROM AUTHOR]

Inspired by nepenthes pitcher plants, the slippery liquid-infused porous surfaces have received extensive attention. In its practical application, good oil storage and oil-locking ability are important guarantee for the surface to maintain the interface performance for a long time. In this paper, mesoporous silica (KCC-1) was obtained by cetyltrimethylammonium bromide (CTAB) as template agent, urea as a hydrolyzing agent, and TEOS as silicon source reagent, then modified with (3-Aminopropyl) trimethoxysilane. Then combined with the breath figures, amino-modified mesoporous silica, 3,3'-4,4'-biphenyltetracarboxylic dianhydride (S-BPDA), 2,2'-bis[4-(4-aminophenoxyphenyl)]propane (BAPP) were used as raw materials to prepare polyimide SLIPS with good stability by a two-step method. The wettability and stability of SLIPS were investigated, and the results show that the introduction of mesoporous silica inorganic nanoparticles enhanced the performance of SLIPS. Among them, the sliding angle of polyimide SLIPS with a nanoparticle content of 10% is 2°, which has good self-cleaning performance, antifouling performance, and stability. [ABSTRACT FROM AUTHOR]

Innovative powder coating system for hydraulic steel construction Unprotected steel corrodes in the atmosphere, water and soil. In order to ensure structural safety and maintain fatigue strength, steel structures of all kinds must be protected from corrosion. Hydraulic steel structures such as locks, gates, canal bridges, ship lifts and water power plants largely characterize our waterways, coastal fortifications and port facilities. They are exposed to a particularly high level of corrosive attack because, in addition to atmospheric influences such as wind and weather, they are particularly affected by water, constant water changes and aggressive substances such as salts and minerals. Since such constructions and buildings usually represent investments of the century, their preservation, use and operational safety over generations is an economic necessity. But it′s not just corrosion that poses a problem for hydraulic steel construction; the formation of biofilms and the growth of algae and mussels can also lead to problems that can even lead to a restriction in the functionality of the systems. The newly developed powder coating system prevents both and thus helps to extend maintenance intervals, increase the lifecycle of steel components in hydraulic steel construction and reduces the lifecycle costs. The new powder coating system thus makes an innovative and sustainable contribution to the preservation of structures in hydraulic steel construction. [ABSTRACT FROM AUTHOR]

Silicone rubber is widely used in various medical applications. However, silicone rubber is prone to biofouling due to their affinity for lipids and has a high friction coefficient, which can significantly impact their efficacy and performance used as medical devices. Thus, the development of hydrogels with antifouling and lubricious abilities for the modification of silicone rubber is in high demand. We herein prepared a variety of hydrogel coatings mainly based on polyvinylpyrrolidone (PVP) and poly (ethylene glycol) diacrylate (PEGDA). We modified the silicone rubber using the prepared hydrogel coatings and cured it using a heating method. Then, we characterized its surface and evaluated the antifouling property, lubricious property, cytotoxicity, sensitization, and vaginal irritation. The results of water contact angle (WCA), protein adsorption, and friction coefficient indicated the success of the modification of the silicone rubber, leading to a significant decrease in the corresponding test values. Meanwhile, the results of cytotoxicity, sensitization, and vaginal irritation tests showed that the hydrogel coating-modified silicone rubbers have an excellent biocompatibility. This study describes how the silicone rubber could be modified with a biocompatible hydrogel coating. The hydrogel coating-modified silicone rubbers have improved antifouling and durable lubricious properties. [ABSTRACT FROM AUTHOR]

Liquid-like surfaces have demonstrated immense potential in their ability to resist cell adhesion, a critical requirement for numerous applications across various domains. However, the conventional methodologies for preparing liquid-like surfaces often entail a complex multi-step polymer brush modification process, which is not only time-consuming but also presents significant challenges. In this work, we developed a single-cycle polymer brush modification strategy to build liquid-like surfaces by leveraging high-molecular-weight bis(3-aminopropyl)-terminated polydimethylsiloxane, which significantly simplifies the preparation process. The resultant liquid-like surface is endowed with exceptional slipperiness, effectively inhibiting bacterial colonization and diminishing the adherence of platelets. Moreover, it offers promising implications for reducing the dependency on anticoagulants in microfluidic systems constructed from PDMS, all while sustaining its antithrombotic attributes. [ABSTRACT FROM AUTHOR]

AFBI E-skin with good biocompatibility integrating antifouling, antibacterial, and breathability functions is developed for self-powered motion monitoring and ultra-long-range human-machine interaction. E-skin shows "dynamic-static" synergistic antibacterial strategy by combination of triboelectric effect and PANI charge action. The ultra-long-range human-machine interaction control system, enables synchronized hand gestures between human hand and robotic hand in any internet-covered area worldwide theoretically. [Display omitted] • AFBI E-skin enables stable signal output for motion monitoring, even when splashed with water. • AFBI E-skin integrates antifouling, antibacterial, biocompatibility and breathability. • AFBI E-skin shows a synergistic effect of "dynamic-static" antibacterial activity. • Ultra-long-range human-machine interaction control system developed using AFBI E-skin. Electronic skin (e-skin) inspired by the sensory function of the skin demonstrates broad application prospects in health, medicine, and human–machine interaction. Herein, we developed a self-powered all-fiber bio-inspired e-skin (AFBI E-skin) that integrated functions of antifouling, antibacterial, biocompatibility and breathability. AFBI E-skin was composed of three layers of electrospun nanofibrous films. The superhydrophobic outer layer Poly(vinylidene fluoride)-silica nanofibrous films (PVDF-SiO 2 NFs) possessed antifouling properties against common liquids in daily life and resisted bacterial adhesion. The polyaniline nanofibrous films (PANI NFs) were used as the electrode layer, and it had strong "static" antibacterial capability. Meanwhile, the inner layer Polylactic acid nanofibrous films (PLA NFs) served as a biocompatible substrate. Based on the triboelectric nanogenerator principle, AFBI E-skin not only enabled self-powered sensing but also utilized the generated electrical stimulation for "dynamic" antibacterial. The "dynamic-static" synergistic antibacterial strategy greatly enhanced the antibacterial effect. AFBI E-skin could be used for self-powered motion monitoring to obtain a stable signal output even when water was splashed on its surface. Finally, based on AFBI E-skin, we constructed an ultra-long-range human-machine interaction control system, enabling synchronized hand gestures between human hand and robotic hand in any internet-covered area worldwide theoretically. AFBI E-skin exhibited vast application potential in fields like smart wearable electronics and intelligent robotics. [ABSTRACT FROM AUTHOR]

Traditional porcelain tiles often lack self-cleaning properties and suffer from aesthetic limitations. This study presents a novel approach for fabricating superhydrophobic, self-cleaning porcelain tiles with enhanced visual appeal. We strategically combined SiO2 and ZnO nanolayers with an antifouling material, applied via spray and drop coating methods. Characterizations (FE-SEM, FTIR, contact angle, UV-Vis, colorimetry, roughness, illuminance, and stain resistance) confirmed the effectiveness of our approach. Heat treatment of the antifouling coating (400 °C) significantly increased hydrophobicity (WCA=119°). SiO2 and ZnO intermediate layers enhanced water repellency, achieving 154° and 149° water contact angles, respectively. This demonstrates superhydrophobicity, in line with Cassie-Baxter's model, and mimics the lotus leaf's self-cleaning mechanism. Low surface energy, likely due to antifouling nanoparticle bonds, contributes to water repellency with roll-off angles of 6° and 7° and causes anti-stain properties on the tile surface. Importantly, these layers optimize surface roughness, boosting hydrophobicity and improving the whiteness and brightness of polished tiles. Surface roughness values of 308 nm (SiO2) and 158 nm (ZnO), along with superior whiteness values (116.4 and 106, respectively), were observed, exceeding surfaces without intermediate layers (57.5). Rayleigh scattering theory explains the whiteness enhancement. Stain resistance significantly improved with intermediate layers, while surface gloss remained unchanged. This research demonstrates the potential of our coating approach to create highly functional and visually appealing polished tiles for diverse industrial applications. [ABSTRACT FROM AUTHOR]

Marine biofouling seriously affects human marine exploitation and transportation activities, to which marine antifouling (AF) coatings are considered to be the most cost-effective solution. Since the mid-20th century, human beings have dedicated their efforts on developing AF coatings with long cycle and high performance, leading to a large number of non-target organisms' distortion, death and marine environmental pollution. Polydimethylsiloxane (PDMS), is considered as one of the representative environment-friendly AF materials thanks to its non-toxic, hydrophobic, low surface energy and AF properties. However, PDMS AF coatings are prone to mechanical damage, weak adhesion strength to substrate, and poor static AF effect, which seriously restrict their use in the ocean. The rapid development of various nanomaterials provides an opportunity to enhance and improve the mechanical properties and antifouling properties of PDMS coating by embedding nanomaterials. Based on our research background and the problems faced in our laboratory, this article presents an overview of the current progress in the fields of PDMS composite coatings enhanced by different nanomaterials, with the discussion focused on the advantages and main bottlenecks currently encountered in this field. Finally, we propose an outlook, hoping to provide fundamental guidance for the development of marine AF field.

Hydrophobic antifouling polymers capable of self‐healing performance are highly desirable for industrial applications. However, the construction of self‐healing, hydrophobic antifouling polymers is challenging considering their complex fouling environments, which are humid in aqueous environment. In this work, a self‐healing hydrophobic polymer containing Fe3+‐catechol coordination applicable to antifouling is synthesized. The hydrophobic fluoroalkyl segments in the polymers formed unique domains dispersed in a polydimethylsiloxane matrix. The as‐synthesized polymers can completely restore their tensile strength, and their self‐healing efficiency is above 90% in both artificial seawater and pure water because of the dynamic Fe3+‐catechol coordination interactions. The as‐synthesized polymer exhibited self‐healing and antifouling properties against common marine bacteria. The colony adhesion and self‐healing processes of the damaged coating in artificial seawater containing marine bacteria are characterized by laser confocal microscopy. This strategy may be useful for the development of future polymeric antifouling materials. [ABSTRACT FROM AUTHOR]

Herein, inspired by the macrophage's defensive behavior of releasing free radicals to kill bacteria and viruses, a marine antifouling coating with dynamic surfaces is prepared by precise regulation of dynamic covalent bonds. Alkyl radical (R·) derived from oxime-urethane structure attracts and disrupts microbe cell membrane and pili between intimate cells, resulting in excellent anti-biofouling effect. Moreover, the newly exposed coating then continues to break, which ultimately results in the peeling of the layers, thus making barnacles, mussels and other fouling organisms less likely to adhere. [Display omitted] • Macrophage-inspired marine antifouling coating with dynamic surfaces is prepared. • Alkyl radical (R·) derived from oxime-urethane structure offers excellent anti-fouling performance. • The newly exposed coating continues to break making it less likely that fouling organisms will adhere to it. • This study presents a novel methodology for fulfilling the technological gap of marine coatings with dynamic surface. Macrophages can kill bacteria and viruses by releasing free radicals, which provides a possible approach to construct antifouling coatings with dynamic surfaces that release free radicals if the breaking of dynamic covalent bonds is precisely regulated. Herein, inspired by the defensive behavior of macrophages of releasing free radicals to kill bacteria and viruses, a marine antifouling coating composed of polyurethane incorporating dimethylglyoxime (PU x -DMG) is prepared by precise regulation of dynamic oxime-urethane covalent bonds. The obtained alkyl radical (R·) derived from the cleavage of the oxime-urethane bonds manages to effectively suppress the attachment of marine biofouling. Moreover, the intrinsic dynamic surface makes it difficult for biofouling to adhere and ultimately achieves sustainable antifouling property. Notably, the PU 50 -DMG coating not only presents efficient antibacterial and antialgae properties, but also prevents macroorganisms from settling in the sea for up to 4 months. This provides a pioneer broad-spectrum strategy to explore the marine antifouling coatings. [ABSTRACT FROM AUTHOR]

DCOIT (4,5-Dichloro-2-octylisothiazol-3(2H)-one) is a widely used antifouling biocide that emerged after the ban on tributyltin. It has been immobilized in nanostructured silica (SiNC–DCOIT) to reduce its hazard in maritime coatings. This study aimed to compare the bioaccumulation, trophic transfer, and biomagnification of DCOIT in its soluble and nanostructured forms on mussels Mytilus galloprovincialis, using three different uptake routes: aqueous exposure (i.e., contaminated seawater), dietary exposure (i.e., microalgae Tetraselmis chuii as a contaminated food), and both contaminated food and seawater. DCOIT was determined on water and tissues after 1, 3, and 24 h of uptake and after 72 h of depuration. Briefly, mussels were able to rapidly uptake and metabolize DCOIT and SiNC–DCOIT. Both compounds were non-bioaccumulative, as their bioconcentration and bioaccumulation factor values were lower than 2000. However, the predator–prey biomagnification factors indicated that both forms could be transferred across the trophic web. Therefore, while our findings provide further insight into the environmental risk assessment of DCOIT and SiNC–DCOIT, they do not rule out the possibility of long-term DCOIT bioaccumulation, particularly in areas with constant DCOIT influx. Further studies are thus needed using larger experimental designs and under continuous exposure scenarios to increase the sustainability of the innovative nanomaterial. [ABSTRACT FROM AUTHOR]

This work describes the fabrication of a novel electroconductive membrane made of Ti3C2Tx (MXene) nanosheet coating through a one‐step pressure‐assisted technique. Ti3C2‐MXene is firmly attached over a polyamide–imide (PAI) microfilter by employing a binder composed of carboxymethyl cellulose (CMC)/glutaraldehyde (GA). Through coating a proper amount of multilayer Ti3C2‐MXene, the electrical conductivity of 174 ± 0.16 S m−1 is achieved. The rejection rates of reactive red 120 (RR120), reactive black (RB), and methyl orange (MO) by the pristine PAI membrane are 45.2%, 40.81%, and 33.65%, respectively. However, rejection rates significantly improve with the Ti3C2 MXene coating to over 99.71%, 97.95%, and 68.91% for RR120, RB, and MO. Applying a 4 V cathodic potential resulted in a flux recovery ratio (FRR) of 99.83% and a flux decline rate (FDR) of less than 1% during humic acid (HA) filtration. Without applying voltage, the MXene‐coated membrane shows an FRR and FDR of 92.51% and 45.56%, respectively. Surface energy analysis reveals strong repulsive interactions between foulants and the membrane surface. Moreover, the surface free energy indicates that foulants such as sodium alginate (SA) and bovine serum albumin (BSA) exhibit stronger adhesion to the membrane than HA, consistent with the fouling experiment results. [ABSTRACT FROM AUTHOR]

Antibacterial resistance is one of the most important global threats to human health. Several studies have been performed to overcome this problem and infection-preventive approaches appear as promising solutions. Novel antimicrobial preventive molecules are needed and microbial biosurfactants have been explored in that scope. Considering their structure, these biomolecules can be divided into different classes, glycolipids and lipopeptides being the most studied. Besides their antimicrobial activity, biosurfactants have the advantage of being biocompatible, biodegradable, and non-toxic, which favor their application in several areas, including the health sector. Often, the most difficult infections to fight are associated with biofilm formation, particularly in medical devices. Strategies to overcome micro-organism attachment are thus emergent, and it is possible to take advantage of the antimicrobial/antibiofilm properties of biosurfactants to produce surfaces that are more resistant to the deposition/attachment of bacteria. Approaches such as the covalent bond of biosurfactants to the medical device surface leading to repulsive physical–chemical interactions or contact killing can be selected. Simpler strategies such as the absorption of biosurfactants on surfaces are also possible, eliminating micro-organisms in the vicinity. This review will focus on the physical and chemical characteristics of biosurfactants, their antimicrobial activity, antimicrobial/antibiofilm approaches, and finally on their structure–activity relationship. [ABSTRACT FROM AUTHOR]

An antifouling peptide hydrogel-based electrochemical biosensor was developed for real-time monitoring of hydrogen peroxide (H2O2) and nitric oxide (NO) released by 3D cultured breast cancer cells upon drug stimulation. Platinum nanoparticles (Pt NPs) were electrodeposited on titanium mesh (Pt NPs/TM) to enhance sensitivity and shown to possess excellent electrocatalytic ability toward H2O2 and NO. The composite hydrogel formed by co-assembling of N-fluorenylmethoxycarbonyl diphenylalanine (Fmoc-FF) and a fluorine methoxycarbonyl group-functionalized Lys-(Fmoc)-Asp was coated on Pt NPs/TM electrode surface to provide cellular scaffolding. Their favorable biocompatibility promoted cell adhesion and growth, while good hydrophilicity endowed the sensor with greatly enhanced antifouling capability in complex cell culture environments. The biosensor successfully determined H2O2 and NO secretion from both non-metastatic and metastatic breast cancer cells in real time. Our results demonstrated robust associations between reactive oxygen species (ROS) and reactive nitrogen species (RNS) production and cell malignancy, with the main difference in oxidative stress between the two subtypes of cells being NO release, particularly emphasizing RNS's critical leading in driving cancer metastasis and invasion progression. This sensor holds great potential for cell-release research under the in vivo-like microenvironment and could reveal RNS as an attractive therapeutic target for treating breast cancer. [ABSTRACT FROM AUTHOR]

A pair of atropisomers secofumitremorgins C (1a) and D (1b), together with fifteen known alkaloids (2-16), were isolated from a saltern-derived fungus Aspergillus fumigatus GXIMD00544. The structures of atropisomers 1a and 1b were elucidated by the detailed spectroscopic data, chemical reaction and quantum chemical calculations. Compounds 1 and 8 displayed antifungal spore germination effects against plant pathogenic fungus associated with sugarcane Fusarium sp. with inhibitory rates of 53% and 77% at the concentration of 100 µM, repectively. Atropisomers 1 also exhibited antifouling potential against Balanus amphitrite larval settlement with an inhibitory rate of 96% at the concentration of 100 µM. [ABSTRACT FROM AUTHOR]

Antifouling paint was introduced and utilized as a control to prevent the problem of biofouling. The Methanolic Crude Extract (MCE) and the Essential Oil (EO) were extracted from Melaleuca cajuputi. Gas Chromatography-Mass Spectrometry (GC-MS) was used to determine the metabolite profiles. An antibacterial assay was conducted via the disc diffusion technique and an antifouling assay of MCE and EO of M. cajuputi was investigated using a crystal violet assay and painted steel panels incorporating MCE and EO. Painted steel panels were immersed in the aquarium to measure the antibiofilm activity and in the natural sea environment to observe the settlement of foulers. The MCE exhibits antibacterial activity against Gram-negative bacteria, indicating narrow-spectrum activity, while EO has broad-spectrum activity against Gram-positive and −negative bacteria. The GC-MS profile showed the presence of cycloheptasiloxane, tetradecamethyl-, cyclotrisiloxane, hexamethyl-, terpinene-4-ol, caryophyllene, and 1,8-cineole in both MCE and EO of M. cajuputi. Crystal violet assay revealed that both samples reduced the attachment of biofilm form by Pseudomonas aeruginosa at 61% and 60%. Panel painted with paint incorporated 5% MCE inhibits bacteria growth in natural seawater, followed by 10% MCE, 5% EO, and 10% EO in aquarium testing. Referring to photographic observation, all the panels coated with paint incorporated with samples successfully reduced the attachment of foulers compared to Blank Paint (BP). In conclusion, these findings indicated that the MCE and EO of M. cajuputi could potentially be used as a substitute for toxic antifoulants to prevent the formation of microfoulers. [ABSTRACT FROM AUTHOR]

Biofouling release coatings (BRCs) have received attention for their potential to limit the negative impacts of biofouling on marine shipping. The calibrated water jet (CWJ, patent # US 8,984,958 B1) can be used to study the effectiveness of BRCs as a function of ship speed. Using a balance of force and linear momentum, we examined the theory and application of the CWJ for simulating the effect of ship speed on biofilm release for surfaces fouled under (1) laboratory and (2) natural conditions. Greater fouling release corresponded with an increase in CWJ pressure and, therefore, simulated ship speed for the surfaces coated with HullKote. The effectiveness of the CWJ was further confirmed for biofilm release from glass fouled naturally by submersion in flow-through seawater. A scaling analysis confirms that the results of these small-scale experiments are applicable to larger-scale biofouling release from ship hulls. This study is the first to utilize the pressure of a CWJ to quantify biofouling release as a function of simulated ship speed. [ABSTRACT FROM AUTHOR]

The current scenario of antifouling (AF) strategies to prevent the natural process of marine biofouling is based in the use of antifouling paints containing different active ingredients, believed to be harmful to the marine environment. Compounds called booster biocides are being used with copper as an alternative to the traditionally used tributyltin (TBT); however, some of them were recently found to accumulate in coastal waters at levels that are deleterious for marine organisms. More ecological alternatives were pursued, some of them based on the marine organism mechanisms' production of specialized metabolites with AF activity. However, despite the investment in research on AF natural products and their synthetic analogues, many studies showed that natural AF alternatives do not perform as well as the traditional metal-based ones. In the search for AF agents with better performance and to understand which molecular motifs were responsible for the AF activity of natural compounds, synthetic analogues were produced and investigated for structure–AF activity relationship studies. This review is a comprehensive compilation of AF compounds synthesized in the last two decades with highlights on the data concerning their structure–activity relationship, providing a chemical toolbox for researchers to develop efficient nature-inspired AF agents. [ABSTRACT FROM AUTHOR]

Polyelectrolytes with strong acidic functionality are among the prime sources for water desalination techniques. Poly 2‐acrylamido‐2‐methylpropanesulfonic acid (PAMPS) is one such polymer showing polyelectrolyte characteristics because of highly acidic SO3H group (pKa < 2) and film‐forming characteristics of flexible polymeric chains. Halloysite nanotubes functionalized with polyelectrolytes can be considered for water purification, as halloysite was reported to be efficient in removing dissolved metal salts. These polyelectrolytes can be introduced as a blend with other components, or they can be synthesized via in situ to form flexible membranes. Polymer nano‐filtration membranes with controlled crosslinking were designed as a function of halloysite and AMPS composition using in situ free radical polymerization with other polymers such as polyvinylidene fluoride and polyvinylpyrrolidone to strengthen the polymer matrix. The synthesized membranes were characterized using FTIR, SEM, EDS, TGA, and DTG techniques. Equilibrium water content, contact angle, water flux, salt rejection efficiency, and antifouling studies are also carried out for these membranes in water purification. [ABSTRACT FROM AUTHOR]

In this study, amino functionalized cellulose nanocrystals–polyethersulfone nanocomposite membrane (A-CNC/PES) based on agricultural waste was used for the removal of diazinon (DZ) from aqueous solution. The fabricated membrane has been characterized via attenuated total reflectance-Fourier transform infrared (ATR-FTIR), scanning electron microscopy (SEM), dispersive X-ray spectrometer (EDX), X-ray diffractometer (XRD), thermal gravimetric analysis (TGA), water contact angel (WCA), porosity, and mean pore radius. The effect of variables, such as initial DZ concentration, pH, and A-CNC content, on the membrane performance was optimized using response surface methodology (RSM) through central composite design (CCD). The results indicated that the additive had the most significant effect on the hydrophilicity improvement, reducing surface roughness, and reducing fouling. The highest removal efficiency of A-CNC/PES membrane for DZ was about 99.3% (at A-CNC: 0.2 wt%), and more than three-fold water flux improvement (27.3 versus 8.3 kg/m2.h for unmodified membrane) was attained. The results of antifouling test confirmed that the A-CNC/PES membranes had a high-flux recovery (FRR: 90.05%). This study may provide promising insights for the development of next generation of agricultural waste-based nanocomposite membrane in the water and wastewater treatment. Highly efficient removal of diazinon pesticide from aqueous solutions by using grape branch-derived CNCs-PES nanocomposite membrane. [ABSTRACT FROM AUTHOR]

The energy crisis of the 1970s sparked growing concern over minimizing fuel consumption in water, land, and air transportation. Researchers fascinated by sharks' effortless swimming abilities investigated shark skin denticles and uncovered functions beyond drag reduction, such as antifouling, protection, and bioluminescence. Over the past five decades, significant progress has been made in comprehending drag reduction and antifouling functions of denticle structures; however, the investigation of other functions remains limited. Recent discoveries of diverse denticle morphologies have ignited a keen interest in obtaining morphogroups that can aid other functional studies. This work integrates advances in antifouling, hydrodynamics, aerodynamics, bioluminescence, and protective functions to provide a holistic understanding of their diverse roles. Additionally, this work also dictates multi‐functional adaptations of denticles and contributes to the relatively less‐explored but essential aspects, such as protective functions and denticle morphogroups. By examining these functions together, this work aims to uncover potential synergies and interactions, facilitating the development of multifunctional materials inspired by shark skin denticles. [ABSTRACT FROM AUTHOR]

Feed spacers improve mixing and mass transfer in membrane modules. However, they also lead to foulant deposition in the vicinity of the spacer surface. In this paper, two hydrophilic monomers, namely, acrylic acid (AA) and 2‐hydroxyethyl methacrylate (HEMA), are respectively coated on the surface of a commercial feed spacer via a plasma‐enhanced chemical vapor deposition (PECVD) method. The resulting modified spacers are then evaluated alongside with a reverse osmosis (RO) membrane for its solute rejection, water permeability, and antifouling properties. Results show that the surface hydrophilicity of feed spacers has been enhanced upon the AA and HEMA deposition. During filtration test, the HEMA‐modified spacer demonstrates higher flux recovery rate (94.17%) and salt rejection (95.78%) for the RO membrane. In contrast, the membrane with the unmodified spacer only shows 89.44% and 92.46%, respectively. Additionally, the membrane with the HEMA‐modified spacer has a thinner fouling layer (200 nm) compared to the unmodified spacer (700 nm). The HEMA‐coated spacer outperforms all the tested spacers, demonstrating that feed spacer modification with a hydrophilic monomer via the PECVD method can effectively reduce membrane fouling. [ABSTRACT FROM AUTHOR]

The recovery of pure water and valuable substances from wastewater is a major challenge in the context of the circular economy, requiring advanced separation methods. However, actual membrane separation techniques such as forward osmosis are limited by membrane fouling and selectivity. Here, we synthesized composite membranes by crosslinking polyvinyl alcohol hydrogel, using both glutaraldehyde and borax as crosslinking agents, on top of cellulose ester membranes. We tested these composite membranes on model and real wastewater. Results show that the composite membranes retain ammonium effectively, maintain surface electroneutrality, and exhibit remarkable resistance to fouling by organic and biological contaminants. This is explained by the high hydrophilicity of the membrane surface after application of a hydrogel layer. [ABSTRACT FROM AUTHOR]

Developing advanced materials with antibacterial and antifouling activities offers an adequate protection solution against surface bacterial contamination—a common cause of infection threatening human health. The current work reports the preparation of polyhydroxybutyrate (PHB) microfiber membranes decorated with photoactive Ag‐TiO2 nanoparticles using electrospinning coupled with dip‐coating methods. The decoration of Ag‐TiO2 nanoparticles strongly enhances the antibacterial properties of prepared membranes, particularly under light illumination, thanks to their photocatalytic activity. The best‐performing sample exhibits potent antibacterial efficiency exceeding 99% against Escherichia coli and Staphylococcus epidermidis after 3 and 1 h of exposure to low‐power commercial LED light, respectively. The prepared samples also display excellent reusability with an insignificant antibacterial activity decrease after three cycles (<2% loss in antibacterial efficiency). Furthermore, these samples effectively prevent bacterial fouling due to their potent antibacterial properties. Notably, despite the strong antibacterial effect, decorated Ag‐TiO2 nanoparticles promote the adhesion of microorganisms, accelerating the biodegradation of PHB microfibers. As a result, the prepared microfiber membranes with nanoparticle decoration exhibit biodegradability comparable to the non‐decorated membrane, with the soil degradation rates reaching almost 99% after only 6 weeks. [ABSTRACT FROM AUTHOR]

Microbial fouling involves the physicochemical interactions between microorganisms and solid surfaces. An electromagnetic field (EMF) may change the diffusion rates of microbial cells and the electrical double layer around the cells and contacting surfaces. In the current study, polycardanol exhibiting antibiofouling activity was modified with ferromagnetic iron oxide (IO) to investigate the EMF effects on bacterial adhesion. When there was a flow of electrolyte that contained bacterial cells, flow-induced EMF was generated according to Faraday's principle. It was observed that the IO-ionic solution (IS)-modified surfaces, with an induced current of 44, 53, 66 nA, showed decreases in the adhesion of bacteria cells more than the unmodified (polycardanol) and IO-nanoparticles-modified ones. In addition to the EMF effects, the nano-scale uniform roughness of the modified surfaces appeared to play an important role in the reduction of cell adhesion. The results demonstrated that the IOIS-modified surface (3.2 × 10−6 mM IO) had the highest antibiofouling activity. [ABSTRACT FROM AUTHOR]

The use of gas diffusion electrodes (GDEs) in microbial fuel cells (MFCs) can improve their cell performance, but tends to cause fouling. In order to allow long-term stable operation, the search for antifouling methods is necessary. Therefore, an antibacterial coating with ammonium compounds is investigated. Within the first 30 days of operation, the maximum measured power density of a GDE with antibacterial ionomer was 606 mW m−2. The GDE without an antifouling treatment could only reach a maximum of 284 mW m−2. Furthermore, there was an optimum in the loading amount with ionomer below 2.6 mg cm−2. Further investigations showed that additional aeration of the GDEs by a fan had a negative effect on their performance. Despite the higher performance, the antibacterial coating could not prevent biofilm growth at the surface of the GDE. The thickness of the biofilm was only reduced by 14–16%. However, the weight of the biofilm on the treated GDEs was 62–80% less than on a GDE without an antifouling treatment. Consequently, the coating cannot completely prevent fouling, but possibly leads to a lower density of the biofilm or prevents clogging of the pores inside the electrodes and improves their long-term stability. [ABSTRACT FROM AUTHOR]

Meeting the ever‐increasing need for clean water requires developing highly effective thin‐film nanocomposite (TFN) membranes with outstanding water permeability, selectivity, and good fouling resistance. In this work, ZnO nanoparticles were synthesized and coated with zwitterionic lysine amino acid (ZnO‐lysine) and then incorporated into a polyamide layer to improve their performance as well as to alleviate fouling. The organic shell on the ZnO‐lysine surface promoted the PA layer's interaction with ZnO‐lysine nanoparticles. TFN membranes demonstrated hydrophilic and smooth polyamide layers with improved permeability and selectivity. In particular, the TFN membranes' enhanced hydrophilicity and smooth surface synergized fouling reduction. In comparison to the bare TFC membrane (12.2 LMH) using 1 M NaCl as the draw solution, the ZnO‐lysine‐modified TFN‐ZL.400 membrane (21.1 LMH) yields a water flux that is 75% greater. In the polyamide layer, the zwitterionic functional groups of ZnO‐lysine not only improved the nanoparticles' chemical compatibility, preventing the creation of nonselective gaps, but also enhanced water flux and salt rejection. This study provides insight into the creation of zwitterionic‐functionalized nanoparticles that can successfully address fouling issues and trade‐off restrictions between selectivity and permeability in TFN membranes. [ABSTRACT FROM AUTHOR]

The impact of zwitterionic graphene oxide (GO‐Arg) nanostructures into polyethersulfone (PES) membranes was studied, aiming to perform mixed matrix membranes (MMMs) with combined antibacterial and antifouling properties. For this purpose, 0.25, 0.50, and 1.0 wt% of GO‐Arg were incorporated through the phase inversion method. The chemical composition reveals that the electrostatic interactions of PES, polyvinylpyrrolidone, and GO‐Arg occur by enhancing the CH/NH vibrations associated with the intrinsic MMMs and their combined antibacterial and antifouling performance. Well‐defined finger‐like morphology was observed, performing the pore distribution and the finger‐cavity inclination induced by the electrostatic charge of GO‐Arg. As a result, GO‐Arg MMM's hydrophobic properties decreased from 77.8° to 52.3°, inducing a partially hydrophilic surface and improved water flux. The isoelectric point of nanostructured membranes slightly changes by the charge modulation produced by zwitterionic GO‐Arg. The antibacterial activity against Gram (−) Escherichia coli was improved, closing the complete bacterial inhibition after 24 h. As a result, antifouling performance was improved, avoiding bacterial adhesion into the membrane surface and the possibility of promoting biofilm formation. Our results demonstrate that zwitterionic nanomaterials in MMMs perform the multifunctional capacity of materials, emerging as an effective alternative with potential application in wastewater treatment. Highlights: The incorporation of zwitterionic GO‐Arg improves the mechanical properties of MMMs.GO‐Arg‐enhanced well‐defined porous finger‐like morphology in MMMs.GO‐Arg improves the antibacterial/antifouling performance of PES‐based MMMs. [ABSTRACT FROM AUTHOR]

Nanoparticle drug-delivery systems (NP DDS) have proven to be tremendously impactful for delivering therapeutic agents in cancer treatments, vaccinations, gene therapy, and diagnostics, and enabled agents such as RNA therapeutics. However, the exposure of NP DDS to biological milieus leads to the rapid adsorption of proteins and other molecules, forming a proteinaceous corona that obscures NP surface characteristics and controls the biological interactions of the NP DDS. Surface modifications, including poly-(ethylene glycol) (PEG) and synthetic zwitterionic polymers, reduce protein adsorption yet lack monomer-scale tunability, have off-target immunological effects, and suffer from targeting-limited steric hindrance, altogether motivating the development of alternative approaches. Peptides can uniquely form many zwitterions and have shown promise in reducing and controlling the NP protein corona as a function of the peptide sequence. However, the impact of zwitterionic peptides (ZIPs) on the drug-delivery properties of polymeric NPs has not been explored. In this work, diverse ZIPs computationally predicted to reduce protein adsorption by assessing peptide–peptide β-strand interaction energies were conjugated to pH-responsive cationic NPs. The resulting ZIP-NP conjugates exhibited up to 88% reduced protein adsorption and a range of siRNA-mediated gene knockdown that correlates with interaction energies. These data suggest that the peptide–peptide interaction energy is a promising design parameter for ZIPs for further model development. ZIP-NP also exhibited sequence-dependent variations in cellular uptake and circulation half-life, indicating that ZIP-NPs are suitable for tuning and improving NP drug-delivery characteristics. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to prepare a multifunctional nanocomposite that is slow-release and resistant to seawater corrosion and biofouling corrosion and to explore the synergistic effect between the two corrosion inhibitors. Design/methodology/approach: The morphology, structure and release properties of CAP@HNTs, BTA@HNTs and CAP/BTA@HNTs were investigated by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, specific surface area analysis and UV spectrophotometry. The corrosion resistance and antimicrobial properties were investigated by electrochemical measurements and bioinhibition rate tests, and the synergistic effect between the two corrosion inhibitors was explored by X-ray photoelectron spectroscopy. Findings: The CAP/BTA@HNTs are responsive to acidic environments and have significantly improved antibacterial and corrosion resistance compared with CAP@HNTs and BTA@HNTs. CAP and BTA have a positive synergistic effect on anticorrosion and antifouling. Originality/value: Two types of inhibitors, anticorrosion and antifouling, were loaded into the same nanocontainer to prepare a slow-releasable and multifunctional nanocomposite with higher resistance to seawater corrosion and biocorrosion and to explore the synergistic effect of CAP and BTA on corrosion resistance. [ABSTRACT FROM AUTHOR]

A sensing interface co-constructed from the two-dimensional conductive material (Ag@MXene) and an antifouling cyclic multifunctional peptide (CP) is described. While the large surface area of Ag@MXene loads more CP probes, CP binds to Ag@MXene to form a fouling barrier and ensure the structural rigidity of the targeting sequence. This strategy synergistically enhances the biosensor's sensitivity and resistance to contamination. The SPR results showed that the binding affinity of the CP to the target was 6.23 times higher than that of the antifouling straight-chain multifunctional peptide (SP) to the target. In the 10 mg/mL BSA electrochemical fouling test, the fouling resistance of Ag@MXene + CP (composite sensing interface of CP combined with Ag@MXene) was 30 times higher than that of the bare electrode. The designed electrochemical sensor exhibited good selectivity and wide dynamic response range at PD-L1 concentrations from 0.1 to 50 ng/mL. The lowest detection limit was 24.54 pg/mL (S/N = 3). Antifouling 2D materials with a substantial specific surface area, coupled with non-straight chain antifouling multifunctional peptides, offer a wide scope for investigating the sensitivity and antifouling properties of electrochemical sensors. [ABSTRACT FROM AUTHOR]

Atmospheric pressure plasma deposition (APPD) of poly(ethylene oxide) (PEO)‐like antifouling coatings provides an attractive way to reduce biofouling for reliable biosensor operation. Cold atmospheric pressure plasma jets are designed to operate in open air. This paper demonstrates the impact of open‐air processing on the composition and properties of PEO‐like coatings by APPD with vinyl ether precursors. The open‐air environment inhibits polymerization as indicated by low deposition rates, oxygen incorporation in the coatings, and instability of the coatings in water. The composition and stability of the coatings improve by appropriate nozzle design and by deposition in an environment with lower air content. The resulting PEO‐like coatings are stable and antifouling for an antibody solution and inhibit adhesion of human fibroblast cells. [ABSTRACT FROM AUTHOR]

Marine biofouling, caused by the deposition and accumulation of marine organisms on submerged surfaces, represents a huge concern for the maritime industries and also contributes to environmental pollution and health concerns. The most effective way to prevent this phenomenon is the use of biocide-based coatings which have proven to cause serious damage to marine ecosystems. Several research groups have focused on the search for new environmentally friendly antifoulants, including marine and terrestrial natural products and synthetic analogues. Some of these compounds have been incorporated into marine coatings and display interesting antifouling activities caused by the interference with the biofilm-forming species as well as by the inhibition of the settlement of macroorganisms. This review highlights the proof-of-concept studies of emerging natural or synthetic antifouling compounds in coatings, from lab-made to commercial ones, performed between 2019 and 2023 and their results in the field or in in vivo laboratorial tests. [ABSTRACT FROM AUTHOR]

Hospital-acquired infections, also known as nosocomial infections, include bloodstream infections, surgical site infections, skin and soft tissue infections, respiratory tract infections, and urinary tract infections. According to reports, Gram-positive and Gram-negative pathogenic bacteria account for up to 70% of nosocomial infections in intensive care unit (ICU) patients. Biofilm production is a main virulence mechanism and a distinguishing feature of bacterial pathogens. Most bacterial pathogens develop biofilms at the solid-liquid and air-liquid interfaces. An essential requirement for biofilm production is the presence of a conditioning film. A conditioning film provides the first surface on which bacteria can adhere and fosters the growth of biofilms by creating a favorable environment. The conditioning film improves microbial adherence by delivering chemical signals or generating microenvironments. Microorganisms use this coating as a nutrient source. The film gathers both inorganic and organic substances from its surroundings, or these substances are generated by microbes in the film. These nutrients boost the initial growth of the adhering bacteria and facilitate biofilm formation by acting as a food source. Coatings with combined antibacterial efficacy and antifouling properties provide further benefits by preventing dead cells and debris from adhering to the surfaces. In the present review, we address numerous pathogenic microbes that form biofilms on the surfaces of biomedical devices. In addition, we explore several efficient smart antiadhesive coatings on the surfaces of biomedical device-relevant materials that manage nosocomial infections caused by biofilm-forming microbial pathogens. [ABSTRACT FROM AUTHOR]

Surfaces that combine low-toxicity antifouling effects with fouling-release properties are an intriguing possibility for developing effective measures against marine biofouling. This study field tested siloxane-based fouling-release surfaces enhanced by adding biodegradable surfactants. Two different surfactants were added to a standard polydimethylsiloxane (PDMS) surface, as well as to PDMS soaked in silicone oil, and compared to controls without surfactant augmentation. Antifouling and fouling-release performance was assessed over 11 to 13 weeks against the most prominent fouling species at three locations in Cape Breton, Nova Scotia, Canada. Using nonlinear mixed effect analysis, surfactants were found to have little impact on the progression of biofouling on PDMS without silicone oil in all three sites and had no additional impact on the progression of biofouling on PDMS augmented with silicone oil. (Silicone oil was found to delay biofouling in PDMS without other additives.) Given the known toxicity of some surfactants to invertebrate larvae, future efforts should consider either higher concentrations or alternative varieties for incorporation into fouling-release surfaces. [ABSTRACT FROM AUTHOR]

The wettability feature is a fundamental and crucial property of solid surfaces which can be easily obtained and adjusted by polymer surface treatment thanks to the wide range of properties of polymers and feasible processing methods. In this study, a simple method was developed to modify the surface of materials using amphiphilic copolymers with zwitterionic groups. Random copolymers poly(dopamine methacrylamide-co-2-(dimethylamino)ethyl methacrylate-co-sulfobetaine methacrylate) (P(DMA-co-DMAEMA-co-SBMA), PDDS) were synthesized by a "one-pot polymerization" method and successfully grafted onto the surface of the substrate by "dip-coating". As the composition of the copolymer can be easily changed, four copolymers with fixed adhesive DMA content and various SBMA contents were obtained where the hydrophilic-hydrophobic balance can be adjusted. The more hydrophobic the copolymer is, the denser and smoother the copolymer coating on silica surface will be obtained. Thus, the wettability of the copolymer modified surface can be controlled by the synergistic effect of adjusting the composition and surface morphology of the copolymer coatings. At the microscopic level, increasing the proportion of SBMA monomer could significantly enhance the hydrophilicity of the coatings, thereby decreasing the adhesive force between modified surface and colloidal probe and improving the antifouling performance of the modified surfaces. At the macroscopic level, owing to their hydrophilicity and underwater superoleophobicity, both PD5D20S75-mesh and PD5S95-mesh exhibited excellent oil/water separation performances with separation efficiency of 97.2% and 98.8%, and water flux of 40692 and 1528 L m−2 h−1, respectively. These results provide a reference for the development of hydrophilic surface materials in different applications. [ABSTRACT FROM AUTHOR]

Clean drinking water has been a challenge due to the pollution from industrialization, urbanization, the growing global population, and lack of infrastructure. Textile industry waste has become a major problem due to wastewater that contains dyes commonly discharged into the water bodies. Wastewater-containing dye should be treated to avoid undesired environmental effects. Among the various water treatment methods, photocatalysis has been getting growing attention in mitigating water pollution issues, particularly in removing organic contaminants (such as organic dyes) due to their good efficiency, low cost, and environmental friendliness. Organic-inorganic composites such as combinations of cellulose and semiconductors can produce unique functional hybrid materials with tailored characteristics. Cellulose has been used as a carrier material due to its superfine network structure, reactive surface groups, and good compatibility with metal oxides. In addition to increasing the catalyst surface area, it improves the photocatalytic effectiveness of nanocomposites by acting as electron acceptors and transporters resulting in a better charge carrier separation. Therefore, cellulose-based photocatalytic membranes are environmentally friendly, fully biodegradable, and biocompatible with efficient applications in wastewater management for the degradation of organic dyes. In this review work, the applications of cellulose-based photocatalytic membranes for the removal of cationic and anionic organic dyes have been reviewed.

The effectiveness of polyvinylidene fluoride (PVDF) membranes in various applications is often hampered by fouling, necessitating the exploration of modification strategies to enhance their antifouling properties. This study investigates the effect of combining cellulose nanocrystal (CNC) and graphene oxide (GO) on PVDF membranes to address this issue. Six flat sheet membranes with different compositions were fabricated using a non-solvent-induced phase separation method. The resulting membrane (M5: CNC 1 % w/w and GO 0.25 % w/w) exhibited increased surface pores, a finger-like cross-sectional structure, and higher water content. The pure water flux (PWF) in the M5 membrane increased to 37 L/m2∙h, with a humic acid (HA) rejection rate of 60 % and excellent antifouling properties (98.32 %). In conclusion, this study successfully modified PVDF membranes by combining CNC and GO, resulting in membranes with improved properties and performance. The present study provides valuable insights into composite membrane design and offers potential solutions to fouling challenges.

The textile industry is one of the leading contributors of liquid waste in the form of synthetic dyes, which significantly contaminate water sources. Heterogeneous photocatalysts employ semiconductors that trigger photocatalytic processes with the assistance of UV or visible light to degrade waste. Tungsten trioxide (WO3) is a potential semiconductor with a small band gap (2.8 eV) that absorbs visible light. WO3 was combined with graphene oxide (GO) and hydroxyapatite (HAp) to exploit the ultrasonication method to degrade methylene blue (MB) dye. The results of the SEM-EDX characterization confirm the constituent elements of the WO3/GO/HAp material. The chemical elements were confirmed by energy-dispersive X-ray spectroscopy. The ability of the original and modified WO3 photocatalysts (WO3/HAp, WO3/GO and WO3/GO/HAp) to degrade 15 ppm of 50 ml of MB solution at concentrations of 10, 15, and 20 mg for 4 h under visible light was investigated. The breakdown of the methylene blue dye demonstrated that the reaction speed followed a first-order pattern. Meanwhile the adsorption isotherm better fit Langmuir for WO3/GO and WO3/GO/HAp. The highest pollutant degradation was achieved using 20 mg WO3/GO and WO3/GO/HAp photocatalysts, which achieved efficiencies of 99.1 % and 98.3 %. These results confirm that the WO3/HAp; WO3/GO, and WO3/GO/HAp hybrid photocatalysts exhibit better degradation performance than unmodified WO3 photocatalysts. Additionally, these photocatalysts can be reused up to three times without experiencing substantial loss in effectiveness.

Abstract Amphiphilic polymer systems have been demonstrated to be an effective and environmentally friendly approach to combat the challenges of biofouling, especially in the real ocean environment. A variety of polymer compositions containing fluorophilic perfluoropolyether (PFPE) urethane dimethacrylate and zwitterionic carboxybetaine methacrylate (CBMA) are in situ copolymerized across a broad concentration range and anchored to chemically functionalized substrates by grafting‐through polymerization. Dynamic accumulation assays with the marine diatom Navicula perminuta and the marine bacterium Cobetia marina revealed an enhanced antifouling performance in most of the amphiphilic polymer mixtures when zwitterionic units are combined with hydrophobic PFPE compounds. It is noticed that the resulting polymer networks still possess enough orientational freedom to quickly rearrange in the presence of water. It is further observed that several of the very hydrophilic formulations and some of the moderately hydrophobic formulations exhibit low fouling against the marine fouling organisms Navicula perminuta and Cobetia marina. This correlated with increased surface roughness and the ability for underwater rearrangement. Furthermore, it is discussed whether the probability that highly hydrated hydrogels, which appear sponge‐like, may create a diffuse interphase which promotes the incorporation of silt. Latter is counteracted by the hydrophobic PFPE building blocks in the amphiphilic coatings.