Antifouling Effect Research Articles

Nanocomposite membrane of alumina nanofibers / poly ether sulfone as blood-contacting biomaterials

This study aimed to determine the physicochemical, mechanical, antifouling, and hemocompatibility effects of electrospun alumina (γ-Al2O3) nanofibers incorporated into polyether sulfone membranes. The γ-Al2O3 nanofibers with mean diameter of 81 ±27 nm were successfully produced using sol-gel and electrospinning methods. By changing the weight ratio of Al2O3 nanofibers to Poly ether sulfone (PES) solution (0, 0.03, 0.05, and 0.1 w/w), different membranes were fabricated using the phase inversion method. With the addition of 0.03 (w/w) Al2O3 nanofibers, the membrane’s pore size increased, but decreased with further nanofiber addition. Energy dispersive spectroscopy mapping analysis revealed that Al3+ ions were successfully distributed throughout the membranes except for those containing 0.1 (w/w) Al2O3. The alumina nanofibers increase the crystallinity and mechanical strength of the PES membrane, while reducing its surface roughness. Alumina content increased in PES membranes resulted in a reduction in flux reduction, improved BSA rejection and antifouling properties, and decreased platelet adhesion and hemolysis, improving hemocompatibility. Overall, PES-0.05 with a mean radius pore of 9.60± 0.90, highest BSA rejection (98.2±0.4) and FRR (72), the lowest platelet adhesion and hemolysis ratio was considered as an optimum membrane.

Sea Anemone-Inspired Slippery Liquid-Infused Porous Surface (SLIPS) with Bionic Cilia for Responsive 4D Antifouling.

The formation process of biofouling is actually a 4D process with both spatial and temporal dimensions. However, most traditional antifouling coatings, including slippery liquid-infused porous surface (SLIPS), are limited to performing antifouling process in the 2D coating plane. Herein, inspired by the defensive behavior of sea anemones' wielding toxic tentacles, a "4D SLIPS" (FSLIPS) is constructed with biomimetic cilia via a magnetic field self-assembly method for antifouling. The bionic cilia move in 3D space driven by an external magnetic field, thereby preventing the attachment of microorganisms. The FSLIPS releases the gaseous antifoulant (nitric oxide) at 1D time in response to light, thereby achieving a controllable biocide effect on microorganisms. The FSLIPS regulates the movement of cilia via the external magnetic field, and controls the release of NO overtime via the light response, so as to adjust the antifouling modes on demand during the day or night. The light/magnetic response mechanism endow the FSLIPS with the ability to adjust the antifouling effect in the 4D dimension of 1D time and 3D space, effectively realizing the intelligence, multi-dimensionality and precision of the antifouling process.

Bioinspired melt-blown fiber felt with flame retardancy for efficient oil spill remediation by solar-driven oil evaporation and adsorption

Confronted with rapid-spread river oil leaks and marine oil spills containing toxic and light fractions, conventional emergency response measures often fall short. This study proposes a solar-driven oil evaporation and adsorption (SOEA) strategy that efficiently addresses the challenges posed by toxic and light oils in rivers and oceans. Inspired by the self-protection and anti-fouling effects of fish scales, a photothermal oil-adsorbing felt with a biomimetic scale structure for efficient SEOA is constructed by decorating functional components onto the melt-blown fiber felt using scalable spraying technology. The rational integration of a dual-layer scale structure and functional constituents imparts stable superhydrophobicity, self-cleaning, flame retardancy, enhanced mechanical strength, and a higher oil adsorption capacity. Benefiting from the superior photothermal conversion, the solar-vapor conversion efficiency of the resulting P-EG/MXene@PP reaches 85.6 % under 1 sunlight, with an evaporation rate for light oil of 13.17 kg/m2/h, 8 times higher than natural volatilization. For crude oil floating on water, it achieves a 98 % oil removal efficiency in 6 h, with 41 wt% of the light fraction evaporated. This research provides distinctive insights into solar-driven oil spill remediation behavior and pioneers the SOEA strategy, offering rapid, efficient, and safe solutions for intricate oil spill scenarios.

PEG-functionalized aliphatic polycarbonate brushes with self-polishing dynamic antifouling properties

Hydrophilic antifouling polymers provide excellent antifouling effects under usual short-term use conditions, but the long-term accumulation of contaminants causes them to lose their antifouling properties. To overcome this drawback, surface-initiated ring-opening graft polymerization (SI-ROP) was performed on the surface of the material by applying the cyclic carbide monomer 4′-(fluorosulfonyl)benzyl-5-methyl-2-oxo-1,3-dioxane-5-carboxylate (FMC), which contains a sulfonylfluoride group on the side chain, followed by a “sulfur(IV)-fluorine exchange” (SuFEx) post click modification reaction to link the hydrophilic polyethylene glycol (PEG) to the polyFMC (PFMC) brush, and a novel antifouling strategy for self-polishing dynamic antifouling surfaces was developed. The experimental results showed that the antifouling surface could effectively prevent the adsorption of proteins such as bovine serum albumin (BSA, ∼96.4%), fibrinogen (Fg, ∼87.8%) and lysozyme (Lyz ∼69.4%) as well as the adhesion of microorganisms such as the bacteria Staphylococcus aureus (S. aureus) (∼87.5%) and HeLa cells (∼67.2%). Moreover, the enzymatically self-polished surface still has excellent antifouling properties. Therefore, this modification method has potential applications in the field of biosensors and novel antifouling materials.

Preliminary hazard assessment of a new nature-inspired antifouling (NIAF) agent

A recently synthesized aminated 3,4-dioxygenated xanthone (Xantifoul2) was found to have promising antifouling (AF) effects against the settlement of the macrofouler Mytilus galloprovincialis larvae. Preliminary assessment indicated that Xantifoul2 has reduced ecotoxicological impacts: e.g., being non-toxic to the marine crustacea Artemia salina (<10 % mortality at 50 μM) and showing low bioconcentration factor in marine organisms. In order to meet the EU Biocidal Product Regulation, a preliminary hazard assessment of this new nature-inspired antifouling (NIAF) agent was conducted in this work. Xantifoul2 did not affect the swimming ability of the planktonic crustacean Daphnia magna, the growth of the diatom Phaeodactylum tricornutum, and the cellular respiration of luminescent Gram-negative bacteria Vibrio fischeri, supporting the low toxicity towards several non-target marine species. Regarding human cytotoxicity, Xantifoul2 did not affect the cell viability of retinal human cells (hTERT-RPE-1) and lipidomic studies revealed depletion of lipids involved in cell death, membrane modeling, lipid storage, and oxidative stress only at a high concentration (10 μM). Accelerated degradation studies in water were conducted under simulated sunlight to allow the understanding of putative transformation products (TPs) that could be generated in the aquatic ecosystems. Both Xantifoul2 and photolytic-treated Xantifoul2 in the aqueous matrix were therefore evaluated on several nuclear receptors (NRs). The results of this preliminary hazard assessment of Xantifoul2, combined with the high degradation rates in water, provide strong evidence of the safety of this AF agent under the evaluated conditions, and provide the support for future validation studies before this compound can be introduced in the market.

Microenvironment-regulated dual-hydrophilic coatings for glaucoma valve surface engineering

Glaucoma valves (GVs) play an essential role in treating glaucoma. However, fibrosis after implantation has limited their long-term success in clinical applications. In this study, we aimed to develop a comprehensive surface-engineering strategy to improve the biocompatibility of GVs by constructing a microenvironment-regulated and dual-hydrophilic antifouling coating on a GV material (silicone rubber, SR). The coating was based on a superhydrophilic polydopamine (SPD) coating with good short-range superhydrophilicity and antifouling abilities. In addition, SPD coatings contain many phenolic hydroxyl groups that can effectively resist oxidative stress and the inflammatory microenvironment. Furthermore, based on its in situ photocatalytic free-radical polymerization properties, the SPD coating polymerized poly 2-methylacryloxyethylphosphocholine, providing an additional long-range hydrophilic and antifouling effect. The in vitro test results showed that the microenvironment-regulated and dual-hydrophilic coatings had anti-protein contamination, anti-oxidation, anti-inflammation, and anti-fiber proliferation capabilities. The in vivo test results indicated that this coating substantially reduced the fiber encapsulation formation of the SR material by inhibiting inflammation and fibrosis. This design strategy for dual hydrophilic coatings with microenvironmental regulation can provide a valuable reference for the surface engineering design of novel medical implantable devices. Statement of significanceSuperhydrophilic polydopamine (SPD) coatings were prepared on silicone rubber (SR) by a two-electron oxidation method. Introduction of pMPC to SPD surface using photocatalytic radical polymerization to obtain a dual-hydrophilic coating. The dual-hydrophilic coating effectively modulates the oxidative and inflammatory microenvironment. This coating significantly reduced protein contamination and adhesion of inflammatory cells and fibroblasts in vitro. The coating-modified SR inhibits inflammatory and fibrosis responses in vivo, promising to serve the glaucoma valves.

Antimicrobial and Antifouling Effects of Petal‐Like Nanostructure by Evaporation‐Induced Self‐Assembly for Personal Protective Equipment (Small 14/2024)

Antimicrobial and Antifouling Effects of Petal‐Like Nanostructure by Evaporation‐Induced Self‐Assembly for Personal Protective Equipment (Small 14/2024)

Fabrication of dual functional marine antifouling coatings by infusing epoxy silicone oil modification of quaternary ammonium

Slippery liquid-infused porous surface (SLIPS) has attracted widespread attention in marine antifouling field, but it lacks the contact-killing ability, which limits its long-term anti-fouling efficiency. Herein, a SLIPS endowed with both resist and contact-killing antimicrobial performances is reported. Firstly, anodic aluminum oxides (AAO) with composite structures of the pores and pyramids were prepared and modified with siloxane. Then, a silicone oil containing quaternary ammonium salt (QAS-SO) groups was synthesized and infused into specially designed AAO, forming a QAS-SLIPS. The surface demonstrated remarkably anti-bacterial performances both Gram-positive Bacillus sp. and Gram-negative V. natriegens, and also maintained essential contact-killing antimicrobial activities from the grafted QAS groups. Biofouling testing suggested excellent antifouling performances of the QAS-SLIPS by declining the adhesion of 90.6 % Phaeodactylum tricornutum and 74.1 % of Chlorella pyrenoidosa. Overall, the antifouling performance of QAS-SLIPS comes primarily from two aspects, including physical isolation and contact-killing. Due to the easy of synthesis and excellent broad-spectrum antifouling effects, the QAS-SO could be potentially used for the development of antifouling coatings or as a lubricant for other devices.

Corrosion and antifouling properties of copper-containing PEO coatings produced on steels

In this work, antifouling copper-containing PEO coatings were produced on zinc-aluminized steels and their antifouling properties in circulating seawater were tested at the Hydrobiological Station Umberto D'Ancona located in Chioggia (Venice, Italy). The effect of the presence of the copper particles on the localized corrosion properties of the PEO coatings was also investigated in depth. In detail, the PEO-coated samples were produced and characterized in terms of microstructure and phase composition through SEM and XRD analysis. The antifouling properties of the samples were evaluated through stereo-microscope and SEM observations after up to 28 days of immersion and the corrosion properties were analyzed with EIS and SVET tests. The results, besides the successful incorporation of the copper particles into the coatings, evidenced the remarkable antifouling effect of the copper particles which also produced a clear selection in the type of algae that can colonize the samples. Considering the corrosion properties, the copper particles were found to be detrimental, due to the galvanic coupling with the substrate. Considering both results, the copper-containing PEO coating can be suggested only in combination with a topcoat which further increases the corrosion performance.

Hierarchical biocide-free silicone/graphene-silicon carbide nanocomposite coatings for marine antifouling and superhydrophobicity of ship hulls

A new series of fluorine-free, nonbiocidal, and hierarchical superhydrophobic silicone coatings filled with reduced graphene oxide (RGO)/β-SiC bamboo-like nanocomposites was successfully fabricated as durable ternary marine fouling release (FR) surfaces. RGO/β-SiC hybrid was used as coating nanofiller that would release fouling and confer surface robustness. It was facilely created using a straightforward one-phase ultrasonication technique. The dispersion of different concentrations of RGO sheets decorated with β-SiC bamboo-like fillers was determined to study the superhydrophobicity and antifouling behaviors of polysiloxane nanocomposites. RGO was prepared through a simple hydrothermal technique. Solution casting was used to distribute the RGO/β-SiC nanofillers throughout a silicone matrix. Atomic force microscopy, surface free energy, and water contact angle (WCA) were employed to examine the superhydrophobicity and micro/nanoroughness of the coatings. The mechanical, anticorrosive, and durability characteristics of the silicone-RGO/β-SiC-filled composites were also investigated. The antifouling effects of the coating systems were evaluated in the laboratory for 30 days with specific bacteria. The silicone-RGO/β-SiC (3 wt%) composite with the best dispersion, highest WCA (156°), and lowest surface free energy (12.7 mN/m) among the composites exhibited favorable FR characteristics. The well-dispersed PDMS-RGO/β-SiC (3 wt% nanofiller) composite presented the minimum degradation and cell viability percentages against Gram-positive and Gram-negative bacteria as well as diatoms. Therefore, this study produced a series of nonstick and fluorine-free ternary FR nanocomposites for maritime coatings with surface durability, superhydrophobicity, and fouling retardancy. This work highlights the design and preparation of multifunctional marine nanocoatings with excellent antifouling performance, easy applicability, and superhydrophobicity properties.

Polysaccharide-Based Coating with Excellent Antibiofilm and Repeatable Antifouling-Bactericidal Properties for Treating Infected Hernia.

In recent years, the utilization of medical devices has gradually increased and implantation procedures have become common treatments. However, patients are susceptible to the risk of implant infections. This study utilized chemical grafting to immobilize polyethylenimine (QPEI) and hyaluronic acid (HA) on the surface of the mesh to improve biocompatibility while being able to achieve antifouling antimicrobial effects. From the in vitro testing, PP-PDA-Q-HA exhibited a high antibacterial ratio of 93% against S. aureus, 93% against E. coli, and 85% against C. albicans. In addition, after five rounds of antimicrobial testing, the coating continued to exhibit excellent antimicrobial properties; PP-PDA-Q-HA also inhibits the formation of bacterial biofilms. In addition, PP-PDA-Q-HA has good hemocompatibility and cytocompatibility. In vivo studies in animal implantation infection models also demonstrated the excellent antimicrobial properties of PP-PDA-Q-HA. Our study provides a promising strategy for the development of antimicrobial surface medical materials with excellent biocompatibility.

Enhancing surface segregation with cyclic polymer additives: A facile approach to surface modification

The preferential surface segregation of one component of a polymer blend has been used for the controlled modification of the surface properties. Unlike other modification methods, this technique is simple and does not require any complex modeling or additional processing steps for surface modification. Most surface segregation studies are based on the interaction between the chain ends of the additive and bulk polymer at the surface. However, additives with cyclic topologies without chain ends have not been used. In this study, an additive platform with cyclic topology without a chain end was designed for surface modification. A series of cyclic additives were synthesized via ring-expansion cationic polymerization. X-ray photoelectron spectroscopy analysis of the cyclic polymer additive showed approximately 1.5 times higher surface segregation than the linear polymer when blended with polyurethane. In addition, the surface segregation behavior depending on the molecular weight and pendant length of the cyclic polymer additive was investigated. Moreover, the monomer, allyl vinyl ether, enabled the addition of functional groups to the cyclic additive and the addition of perfluoroalkyl pendant groups was performed, revealing a promising antifouling effect in the adsorption of a plasma protein. The high performance and versatility of the cyclic architectural polymer additives extend the scope of the surface segregation field and can replace existing biomedical coatings.

Possible anti-fouling effect of polyenes in molluscs shell

Polyenes were analysed in two species of marine gastropods (the periwinkles Littorina brevicula and Littorina mandshurica) and two species of marine bivalves (the mussels Mytilus trossulus and Crenomytilus grayanus) to determine the relationship of these compounds with the fouling of molluscs shell. It was found that the shells of the Littorina gastropods and M. trossulus, which are rarely overgrown by fouling organisms in nature, contained polyenes. In rare cases of fouling by Balanus barnacles, there were no polyenes at the sites of their attachment on the shells. Polyenes were not found in the shells of C. grayanus, which are often prone to fouling. The role of polyenes in the possible anti-fouling properties of molluscan shells is discussed.

Preventing Static Biofilm Formation of Staphylococcus aureus on Different Types of Surfaces Using Microbubbles.

Bacterial fouling and biofilm formation on surfaces have been ongoing problems in real life as well as in the medical field. Different approaches have been taken to tackle the issues, from costly surface modification to antibiotic-delivering strategies. In this study, we examined the potential of using stabilized microbubbles (MBs) to shield against bacterial adhesion. Three types of surfaces were tested: hydrophilic glass (hydrophilic surface), neutral hydrophobic polystyrene (PS)-coated surfaces, and negatively charged hydrophobic octadecyltrichlorosilane (OTS)-coated surfaces. By evaluating the colony-forming unit (CFU) values from each surface, MBs stabilized by 0.05 mM SDS were shown to only produce significant reduction of Staphylococcus aureus adhesion on PS surfaces, up to 60.29 and 82.32% compared to no-MB PS surfaces, and no-MB uncoated surfaces, correspondingly, due to the appropriate size, stability, and negative charges of the MB shielding layer. On the other hand, OTS coatings had an intrinsic antiadhesion effect (69.83% compared to uncoated surface), given that the negatively charged OTS-aqueous interface or surface porosity nature of the coating prohibited the attachment of MBs, leading to the elimination of the antifouling effect of MBs. Ultimately, MBs gave better shielding results than surface modification when compared to uncoated surfaces and hence can be applied more widely.

A superhydrophobic nanofiber membrane and its application to dye filtration using membrane distillation

Direct contact membrane distillation tests are carried out on four kinds of dye solutions using the superhydrophobic polyvinylidene difluron-copolymerized hexafluoro-propylene nanofiber membrane (PH-E) and its modification coated with polydime-thylsiloxane (PDMS) nanoparticles (PDMS-PH-E membrane). The test results show that PDMS-PH-E membrane has higher water flux, and the removal efficiency of four dyes reaches 100%. While the removal efficiency of the PH-E membrane reaches 100% only for two dyes. The loosely absorbed dye structure on PDMS-PH-E membrane roughens the surface, and stimulates the negatively charged droplets to bounce, resulting in an effective anti-fouling and self-cleaning effect and a long-term scaling prevention.

A highly reactive soybean oil-based superhydrophobic polyurethane film with long-lasting antifouling and abrasion resistance.

Superhydrophobic polyurethanes offer robust hydrophobicity and corrosion resistance. However, it is essential to consider the durability and environmental constraints associated with these materials. This study prepared a bio-based superhydrophobic polyurethane coating film using epoxidized soybean oil, superhydrophobically modified silica nanoparticles, and OH-PDMS-OH as surface modifiers. The coating film exhibited sustained super-hydrophobicity and an excellent antifouling effect for pu-erh tea and edible oils, among other substances, after 14 days of immersion in solutions with different pH values, 28 days of exposure to air, and 2000 abrasion cycles. This finding can be applied to the development of daily indoor and outdoor antifouling protective coatings and provides a new method for the preparation of green and durable superhydrophobic antifouling coating films.

Ultra-high strength sodium alginate/PVA/PHMB double-network hydrogels for marine antifouling

Although hydrogel have attracted tremendous attention as antifouling material, it is still challenging to develop an antifouling hydrogel that combines superior mechanical properties with excellent antifouling effect. Here, a high-strength polyvinyl alcohol/sodium alginate double-network (DN) antibacterial and antifouling hydrogel was synthesized by introducing polyhexamethylene biguanide hydrochloride (PHMB) potent fungicide. The as-prepared hydrogel demonstrated high tensile strength (17.23 MPa), excellent anti-protein adhesion ability (0.09 %, anti-diatom adhesion rate), and outstanding antibacterial ability (100 % sterilization rate). The antifouling experiments have verified that DN-PHMB hydrogel remains non-attachment even after >6 months in the actual marine environment. These distinctive capabilities of DN-PHMB hydrogels hold promising candidate for marine antifouling materials.

An anionic polyethersulfone membrane modified by poly(2-acrylamide-2-methylpropanesulfonic acid sodium salt) grafted carbon nanotubes

Polyethersulfone membrane is easy to be polluted, and the negative surface would help enhance improve the permeability and the anti-pollution performance; so how to anchor polymer brushes with negative groups to polyethersulfone membrane surface is a challenge. In this paper, polymer brushes of poly(2-acrylamide-2-methylpropanesulfonic acid sodium salt) is first grafted to carbon nanotubes to form an organic-inorganic hybrid additive, which is further anchored onto the membrane surface of polyethersulfone by blending method. The graft reaction is proceeded by surface initiated electrochemical atom transfer radical polymerization, where the introduction of electrochemical part is because it could help better control the growth of polymer brushes compared with the pristine atom transfer radical polymerization process. The carbon nanotubes grafted with poly(2-acrylamide-2-methylpropanesulfonic acid sodium salt) could anchor on the membrane surface because the there is a self-assemble process of organic-inorganic hybrid additive during phase inversion method, where the inorganic part carbon nanotubes firmly embedded into the membrane and the organic part can be fixed on membrane surface. The polyethersulfone membrane exhibits enhanced surface hydrophilicity, improved the permeability of the membrane, and good anti-fouling performance due to the negative charge and electrostatic repulsion brought by anionic surface of the modified membrane. When the mass of nanotubes grafted with poly(2-acrylamide-2-methylpropanesulfonic acid sodium salt) in the casting solution is 20 mg, the water flux can reach 365.5 L m−2 h−1, and the rejection ratios of both BSA and CR are close to 100% with good flux recovery and anti-fouling effect performance.

Slippery Porous-Liquid-Infused Porous Surface (SPIPS) with On-Demand Responsive Switching between "Defensive" and "Offensive" Antifouling Modes.

Slippery liquid-infused porous surfaces (SLIPS) have received widespread attention in the antifouling field. However, the reduction in antifouling performance caused by lubricant loss limits their application in marine antifouling. Herein, inspired by the skin of a poison dart frog which contains venom glands and mucus, a porous liquid (PL) based on ZIF-8 is prepared as a lubricant and injected into a silicone polyurethane (SPU) matrix to construct a new type of SLIPS for marine antifouling applications: the slippery porous-liquid-infused porous surface (SPIPS). The SPIPS consists of a responsive antifoulant-releasing switch between "defensive" and "offensive" antifouling modes to intelligently enhance the antifouling effect after lubricant loss. The SPIPS can adjust antifouling performance to meet the antifouling requirements under different light conditions. The wastage of antifoulants is reduced, thereby effectively maintaining the durability and service life of SLIPS materials. The SPIPS exhibits efficient lubricant self-replenishment, self-cleaning, anti-protein, anti-bacterial, anti-algal, and self-healing (97.48%) properties. Furthermore, it shows satisfactory 360-day antifouling performance in actual marine fields during boom seasons, demonstrating the longest antifouling lifespan in the field tests of reported SLIPS coatings. Hence, the SPIPS can effectively promote the development of SLIPS for neritic antifouling.

Increased hydrophilicity and anti-fouling effect of orthokeratology lenses coated with NVP and PEGMA by plasma-enhanced chemical vapor deposition

Increased hydrophilicity and anti-fouling effect of orthokeratology lenses coated with NVP and PEGMA by plasma-enhanced chemical vapor deposition