Prevention Of Marine Biofouling Research Articles

MXene and cellulose nanofibers reinforced hydrogel with high strength and photothermal self-healing performances for marine antifouling

Biological fouling is a considerable threat to the marine industry because attached microcontaminants and microorganisms inflict serious damage on marine installations and aquacultures. Although there has been tremendous effort in researching marine antifouling, it is yet challenging to develop a long-term and consistent antifouling strategy and materials. Here, polyhexamethylene-biguanide (PHMB) and MXene are introduced into the carboxylated cellulose nanofibers (CNF) reinforced polyvinyl alcohol (PVA) hydrogel to obtain a self-healing and ultra-high toughness antifouling hydrogel. The as-prepared double network (DN) hydrogels have extremely high toughness (16,050 kJ/m3), superior anti-protein adhesion (100 %) and anti-algal adhesion (100 %), exceptional antibacterial activity (99.97 %), and remarkable photothermal self-healing capability. Furthermore, the DN hydrogel provide outstanding antifouling performance for at least six months in the actual marine field. This work provides an effective and feasible strategy to prevent marine biofouling and also initiates new approaches to the application of hydrogel.

Investigation of an Antifouling Compound from Sponge Siphonodictyon coralliphagum

Marine fouling is attaching organisms to objects floating or submerged in seashores, such as ships, docks, and offshore structures. The impact caused is the reduced lifespan of the thing attached to the biofouling. In addition, there was a spread of invasive species. The government and industries in the United States spend over 6.5 million dollars annually on their budget to overcome this problem. So far, the prevention of marine biofouling is using antifouling paint on ships and submerged structures. One of them is organotin tributyltin (TBT) proven effective for preventing fouling; however, it is not environmentally friendly. Sponge Siphonodictyon coralliphagum growing in Salibabu Island waters, Talaud Islands, with previously shown activities against prokaryotes, was collected and extracted by maceration using ethanol as a solvent. The extract was then added to the base paint with several compositions of 5%, 10%, and 25% applied to the paving block surface. Positive control uses paint with copper additives. The objects are then immersed in the seashore below subtidal depths. The observation was carried out every seven days until day 28. The paving block was observed on day 90 after immersion. Significant results were obtained where macrofouling was only able to grow in negative control and positive control. The extract sponge S. coralliphagum has vigorous antifouling activity against marine biofouling. Furthermore, the extract was fractionated using liquid chromatography and continued by testing their activity against Gram-positive and negative bacteria. Further investigation of NMR spectra from the active fraction to prokaryotic cells shows a cyclic aliphatic compound with several keto-enol functional and methyl aliphatic groups on their chain.

The Role of Natural and Synthetic Flavonoids in the Prevention of Marine Biofouling.

Marine biofouling is a major concern for the maritime industry, environment, and human health. Biocides which are currently used in marine coatings to prevent this phenomenon are toxic to the marine environment, and therefore a search for antifoulants with environmentally safe properties is needed. A large number of scientific papers have been published showing natural and synthetic compounds with potential to prevent the attachment of macro- and microfouling marine organisms on submerged surfaces. Flavonoids are a class of compounds which are highly present in nature, including in marine organisms, and have been found in a wide range of biological activities. Some natural and synthetic flavonoids have been evaluated over the last few years for their potential to prevent the settlement and/or the growth of marine organisms on submerged structures, thereby preventing marine biofouling. This review compiles, for the first-time, natural flavonoids as well as their synthetic analogues with attributed antifouling activity against macrofouling and microfouling marine organisms.

Prevention of marine biofouling in the aquaculture industry by a coating based on polydimethylsiloxane-chitosan and sodium polyacrylate

In this study, a series of novel hydrophobic/hydrophilic hybrid (HHH) coatings with the feature of preventing the fouling phenomenon was fabricated based on polydimethylsiloxane (PDMS), as matrix and two hydrophilic polymers: chitosan and sodium polyacrylate, as dispersed phases. Antibacterial activity, pseudo-barnacle adhesion strength, surface free energy, water contact angle, and water absorption were performed for all samples. Evaluating field immersion of the samples was performed in the natural seawater. The results showed that the dispersed phase containing PDMS coatings showed simultaneously both of antibacterial activity and foul release behavior. Among the samples, the PCs4 coating containing 4 wt% Cs indicated the lowest pseudo barnacle adhesion strength (0.04 MPa), the lowest surface free energy (18.94 mN/m), the highest water contact angle (116.05°), and the percentage of fouling organisms 9.8 % after 30 days immersion. The HHH coatings can be considered as novel eco-friendly antifouling/foul release coatings for aquaculture applications.

Production and Physicochemical Characterization of Antifouling Biocomposites; The Effect of Chitosan and ZnO to Prevent Marine Biofouling

Adhesion of biofouling organism creates various problems. Efforts to explore the source of the antifouling material from marine organisms have been carried out, but it is non-cultivable mainly; its work efficiency depends on temperature, pH, concentration, and ineffective exposure time. Therefore, it is necessary to explore new sources of antifouling material by developing antifouling biocomposites from chitosan-ZnO. This study aims to determine the effect of differences in concentration of chitosan and ZnO on biocomposite characterization. This study consisted of 3 stages, 1) characterization of chitosan and ZnO; 2) production and characterization of chitosan-ZnO biocomposite; and 3) antifouling activity testing. The results showed that chitosan was completely soluble in 2% acetic acid with a viscosity of 76.4 to 79.6%, a water content of 10.92%, ash of 1.92%, nitrogen of 3.70%, and a deacetylation level of 85%. The ZnO used in this study had a particle size of 396.1-458.7 nm. Biocomposite characteristics indicated that the best treatment was chitosan 1% -ZnO 0.6 g with 0.31% swelling, 0.18% solubility film, 104.50° hydrophobic and 4.50 MPa adhesion. The results of the anti-fouling tests showed that the treatment of chitosan 1% -ZnO 0.6 g had less biofouling than other treatments.

Application of functional polymer materials for marine anti-fouling

Marine organisms adsorb and grow on the surface of underwater facilities. This process, known as fouling, has a detrimental impact on marine shipping and development. Currently, in order to prevent marine biofouling, the most efficient and economical method is the application of antifouling coatings that synthesized by a diverse of different functional polymer materials. For this reason, this research will introduce the progress in five types of functional polymer materials, which are polymers with catechol groups, polysulfide-based polymers, polymer quaternary ammonium salts, hydrogels and silicone resin. Due to different functional groups properties as well as mechanisms of action, they have their own advantages in the application of antifouling coatings. Meanwhile, the future trend of antifouling coatings development and their application in real sea environment are prospected.

Synthesis and Properties of Self-Polishing Antifouling Coatings Based on BIT-Acrylate Resins

Painting antifouling coatings is one of the most important methods to prevent marine biofouling. Acrylic resin is widely used in marine antifouling because of its excellent stickiness, water resistance, and film-forming capabilities. At present, the widely used acrylate antifouling coatings require a high concentration of cuprous oxide as antifoulant. The release and accumulation of copper ions are the main factors affecting the marine environment. In this study, BIT–allyl methacrylate (BM) and zinc acrylate (ZM) were selected as functional monomers copolymerized with methyl methacrylate (MMA) and butyl acrylate (BA) to prepare a series of BIT acrylate antifouling resins. The inhibitory effects of all resins against marine bacteria (S. aureus, V. coralliilyticus, and V. parahaemolyticus), marine algae (Chlorella, I. galbana, and C. curvisetus), and barnacle larvae were studied. Moreover, marine field tests on the BIT modified resin in coastal waters were conducted. The results demonstrate that the grafted BIT–zinc acrylate resin not only exhibits excellent antifouling properties but also a significant self-polishing performance, providing a novel strategy to design a long-term antifouling resin with stable antifoulant release.

Using Virtual AChE Homology Screening to Identify Small Molecules With the Ability to Inhibit Marine Biofouling

The search for effective yet environmentally friendly strategies to prevent marine biofouling is hampered by the large taxonomic diversity amongst fouling organisms and a lack of well-defined conserved molecular targets. The acetylcholinesterase enzyme catalyses the breakdown of the neurotransmitter acetylcholine, and several natural antifouling allelochemicals have been reported to display acetylcholinesterase inhibitory activity. Our study is focussed on establishing if acetylcholinesterase can be used as a well-defined molecular target to accelerate discovery and development of novel antifoulants via sequential high-throughput in silico screening, in vitro enzymatic studies of identified compound libraries, and in vivo assessment of the most promising lead compounds. Using this approach, we identified potent cholinesterase inhibitors with inhibitory concentrations down to 3 μM from a 10,000 compound library. The most potent inhibitors were screened against five microfouling marine bacteria and marine microalgae and the macrofouling tunicate Ciona savignyi. No activity was seen against the microfoulers but a potent novel inhibitor of tunicate settlement and metamorphosis was discovered. Although only one of the identified active cholinesterase inhibitors displayed antifouling activity suggesting the link between cholinesterase inhibition and antifouling is limited to certain compound classes, the study highlights how in silico screening employed regularly for drug discovery can also facilitate discovery of antifouling leads.

From Natural Xanthones to Synthetic C-1 Aminated 3,4-Dioxygenated Xanthones as Optimized Antifouling Agents.

Biofouling, which occurs when certain marine species attach and accumulate in artificial submerged structures, represents a serious economic and environmental issue worldwide. The discovery of new non-toxic and eco-friendly antifouling systems to control or prevent biofouling is, therefore, a practical and urgent need. In this work, the antifouling activity of a series of 24 xanthones, with chemical similarities to natural products, was exploited. Nine (1, 2, 4, 6, 8, 16, 19, 21, and 23) of the tested xanthones presented highly significant anti-settlement responses at 50 μM against the settlement of mussel Mytilus galloprovincialis larvae and low toxicity to this macrofouling species. Xanthones 21 and 23 emerged as the most effective larval settlement inhibitors (EC50 = 7.28 and 3.57 µM, respectively). Additionally, xanthone 23 exhibited a therapeutic ratio (LC50/EC50) > 15, as required by the US Navy program attesting its suitability as natural antifouling agents. From the nine tested xanthones, none of the compounds were found to significantly inhibit the growth of the marine biofilm-forming bacterial strains tested. Xanthones 4, 6, 8, 16, 19, 21, and 23 were found to be non-toxic to the marine non-target species Artemia salina (<10% mortality at 50 μM). Insights on the antifouling mode of action of the hit xanthones 21 and 23 suggest that these two compounds affected similar molecular targets and cellular processes in mussel larvae, including that related to mussel adhesion capacity. This work exposes for the first time the relevance of C-1 aminated xanthones with a 3,4-dioxygenated pattern of substitution as new non-toxic products to prevent marine biofouling.

The Presence of Marine Filamentous Fungi on a Copper-Based Antifouling Paint

Marine biofouling is undesirable growth on submerged substances, which causes a major problem for maritime industries. Antifouling paints containing toxic compounds such as copper are used to prevent marine biofouling. However, bacteria and diatoms are usually found in biofilms developed on such paints. In this study, plastic panels painted with a copper-based self-polishing antifouling paint were exposed to biofouling for 6 months in the Marina Bandar Rowdha, Sea of Oman. Clean panels were used as a control substratum. Marine filamentous fungi from protected and unprotected substrate were isolated on a potato dextrose agar. Pure isolates were identified using sequences of the ITS region of rDNA. Six fungal isolates (Alternaria sp., Aspergillus niger, A. terreus, A. tubingensis, Cladosporium halotolerans, and C. omanense) were obtained from the antifouling paint. Four isolates (Aspergillus pseudodeflectus, C. omanense, and Parengyodontium album) were isolated from clean panels and nylon ropes. This is the first evidence of the presence of marine fungi on antifouling paints. In comparison with isolates from the unprotected substrate, fungi from the antifouling paint were highly resistant to copper, which suggests that filamentous fungi can grow on marine antifouling paints.

The Application of UVC Used in Synergy with Surface Material to Prevent Marine Biofouling

Biofouling is problematic for the shipping industry and can lead to functional and financial setbacks. One possible means of biofouling prevention is the use of ultraviolet-C (UVC) light. Previous studies have investigated UVC with marine coatings, but the synergistic effect with color and surface material, specifically reflectance, has yet to be determined. This study comprised three parts: UVC and color (red vs. white), UVC and reflectance (stainless steel vs. polycarbonate), and UVC and exposure intervals (weekly intervals and 10 min intervals). There was no variance in the biofouling communities for colored surfaces when exposed to 254 nm UVC. Reflectance studies demonstrated that the surface material plays a role in biofouling settlement. Stainless steel panels had significantly greater macrofouling settlement than polycarbonate, specifically among encrusting bryozoan, tubeworms, and tunicate communities. Panels of both surface materials exposed to indirect UVC significantly differed from controls and those exposed directly to UVC. Exposure intervals were also found to reduce biofouling settlement especially with long frequent intervals (i.e., 10 min/day). UVC can be utilized on various colored surfaces and different surface types, but the effectiveness in preventing biofouling is ultimately determined by the duration and frequency of UVC exposure.

Room temperature synthesis of defective cerium oxide for efficient marine anti-biofouling

Mimicking marine algae to prevent marine biofouling on the submerged surface of engineering materials represents an alternative and promising approach to conventional toxic anti-biofouling strategy. Here, a novel CeO2 is synthesized by a simple room temperature approach. The as-synthesized CeO2 with rich oxygen vacancies exhibits significantly higher intrinsic haloperoxidase-like activity than the conventional CeO2 in catalyzing the bromination reaction of organic substrates, with a bromination reaction rate of 0.13 µM min−1 at a concentration of 0.05 mg mL−1. In the presence of Br− and H2O2 oxidant, CeO2 demonstrates significant antibacterial efficacies against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, with a significant antibacterial efficiency of 88% and 90%, respectively. Field tests reveal that the plates containing the defective CeO2 (5 wt.%) can effectively hinder the marine biofouling in open ocean. This work provides a promising approach for the development of effective and green marine inorganic anti-foulants at room temperature. Defective CeO2 demonstrates haloperoxidase-like activity towards the catalytic oxidation of bromide, highlighting the potential application towards marine anti-biofouling.

Natural polyketide 6-pentyl-2H-pyrone-2-one and its synthetic analogues efficiently prevent marine biofouling

Biofouling is a widespread phenomenon in oceans worldwide. With increasing human development and activities in open and coastal waters, and due to the environmental impact of AF organotins and copper-based paint, the demand for nontoxic antifouling (AF) paints is increasing. Various bioassays for antimicrobial activity, anti-biofilm formation and anti-barnacle settlement were established to evaluate the possibility of using marine natural products as AF agents. A series of natural products, isolated from the marine-derived fungi Trichoderma atroviride and T. reesei, were evaluated for their AF activity. One pyrone-type compound (1) demonstrated significant inhibitory activities toward barnacle cyprid settlement. Furthermore, a series of pyrone analogues (S1–S6) were synthesized, and their bioactivities were evaluated in the established systems. The results showed that compounds S5 and S6 exhibited a broad spectrum of bioactivities, such as anti-barnacle settlement, anti-biofilm formation and antimicrobial activities.

Preparation and antifouling performance evaluation of fluorine-containing amphiphilic silica nanoparticles

Ocean-going ships, deep-sea equipment, coastal facilities, and other underwater surfaces are often attached to and fouled by marine microorganisms, animals, and plants, leading to damage, equipment failure or major economic losses in severe cases. Therefore, it is of great significance to take measures to prevent marine biofouling. To date, no single eco-friendly technology has been developed to achieve good antifouling effects. Therefore, the combination of multiple antifouling factors is still one of the main strategies to strengthen antibiofouling performance. In this paper, amphiphilic block copolymer (PTFEMA-co-PSBMA) functionalized silica (SiO2) nanoparticles of SiO2-g-(PTFEMA-co-PSBMA) were prepared by surface initiated atom transfer radical polymerization (SI-ATRP), and then they were physically blended with polydimethylsiloxane (PDMS) matrix to prepare one kind of novel antifouling coating. Compared with control silicone rubber coating and bare SiO2-dopped silicone rubber coating, the experiment results show that the diatom density on the surface of the copolymer functionalized silica nanoparticle-dopped coating is reduced by approximately 30 % and 50 %, respectively. Furthermore, upon employing washing process, it is found that the highest removal rate of diatoms on the surface of the copolymer functionalized silica nanoparticle coating is 50 %, which is approximately twice the removal rate of the unmodified SiO2 silicone rubber coating. Finally, it is found that the surface of the copolymer functionalized silica nanoparticle coating still has good antifouling and fouling release properties upon encountering wear test. These above results prove that the coatings with functionalized nanosilica nanoparticles have better antifouling performance. Current strategy in this work provides a new route for developing environmentally friendly fouling-releasing antifouling coatings.

Toward the Application of Graphene for Combating Marine Biofouling

AbstractThe discovery of graphene has brought great innovations to materials science. Since tributyltin antifouling coatings were banned worldwide in 2008, the development of green antifouling coatings has become necessary. Recently, novel graphene‐related antifouling coatings have been the focus of many studies due to their enhanced mechanical strength, excellent antifouling capabilities, and environmental friendliness. This review starts by introducing the basic antifouling mechanisms of graphene nanosheets and the possible antifouling mechanisms when graphene is incorporated into coatings. Subsequently, the progress and existing problems regarding the application of graphene in the prevention of marine biofouling are discussed. Specifically, this review focuses on six graphene‐related antifouling coatings, including pure graphene film, nanohybrids, foul release coatings, photocatalytic nanocomposites, desalination membranes, and materials for uranium enrichment. The fabrication, antifouling properties, working mechanisms, and future development of graphene‐related antifouling coatings are highlighted. In addition, the potential environmental risk of using graphene materials in preventing marine biofouling is explained, and the basic requirements for designing an environmentally friendly graphene‐related antifouling coating are discussed. Finally, the prospect of applying graphene materials for combating marine biofouling is presented. This review aims to aid in improving the design of graphene‐related green antifouling coatings.

Self-Sterilizing Polymeric Membrane Sensors Based on 6-Chloroindole Release for Prevention of Marine Biofouling.

A self-sterilizing strategy based on antimicrobial organic agent release is proposed for polymeric membrane sensors to prevent marine biofouling. A solid-contact polymeric membrane calcium ion-selective electrode (Ca2+-ISE) is selected as a model sensor. 6-Cholorindole (6-Cl indole) is utilized as the biocidal agent due to its potential antimicrobial activity and environmental friendliness. The plasticized polymeric membrane doped with 6-Cl indole shows a markedly improved antimicrobial activity against the bacterial cells collected from seawater and effectively prevents the formation of a biofilm on the sensor surface, while displaying response properties (i.e., linear range, selectivity, and response time) similar to those of the undoped membrane. Importantly, the present sensor can preserve an improved antimicrobial activity when kept in the artificial seawater for 45 days, indicating highly stable antibacterial properties of the membrane electrode. Additionally, the 6-Cl indole-doped Ca2+-ISE exhibits no significant loss of analytical performance after exposure to a rather concentrated bacterial suspension (∼109 colony-forming units per mL (CFU mL-1)) for 7 days. The proposed antimicrobial agent release methodology can be extended to develop polymeric membrane-based marine sensors with stable biofouling resistances against bacterial colonization.

Rational Design of Transparent Nanowire Architectures with Tunable Geometries for Preventing Marine Fouling

AbstractMarine biofouling is a sticky global problem that hinders maritime industries. Various microscale surface structures inspired by marine biological species have been explored for their anti‐fouling properties. However, systematic studies of anti‐marine‐fouling performance on surface architectures with characteristic length‐scales spanning from below 100 nm to greater than 10 µm are generally lacking. Herein, a study on the rational design and fabrication of ZnO/Al2O3 core–shell nanowire architectures with tunable geometries (length, spacing, and branching) and surface chemistry is presented. The ability of the nanowires to significantly delay or prevent marine biofouling is demonstrated. Compared to planar surfaces, hydrophilic nanowires can reduce fouling coverage by up to ≈60% after 20 days. The fouling reduction mechanism is mainly due to two geometric effects: reduced effective settlement area and mechanical cell penetration. Additionally, superhydrophobic nanowires can completely prevent marine biofouling for up to 22 days. The nanowire surfaces are transparent across the visible spectrum, making them applicable to windows and oceanographic sensors. Through the rational control of surface nano‐architectures, the coupled relationships between wettability, transparency, and anti‐biofouling performance are identified. It is envisioned that the insights gained from the work can be used to systematically design surfaces that reduce marine biofouling in various industrial settings.

Bioinspired superhydrophobic and oil-infused surface: Which is the better choice to prevent marine biofouling?

Bioinspired superhydrophobic and oil-infused surfaces have been recognized as interesting and promising materials for a wide range of applications correlated with water environment, such as corrosion and biofouling inhibition. Which material is the better choice still waits to reveal. In this study, taking stainless steel as the substrate, superhydrophobic and oil-infused surface based on Cu(OH)2 matrix with prickly chestnut husk morphology is respectively obtained via successive steps. During the preparation of superhydrophobic surface, firstly, discrete Cu particles are electrodeposited onto stainless steel. After that, oxidation of the as-deposited Cu particles leads to the prickly Cu(OH)2 following a dissolution-crystallization mechanism. Under a mild condition, dodecanethiol vapor modifies prickly matrix to achieve superhydrophobicity by anchoring the long-chain organic moiety onto Cu(OH)2 surface. Since superhydrophobic matrix is intrinsically superoleophilic, oil-infused surface is finally constructed onto stainless steel. Taking typical marine fouling organisms including sulfate-reducing bacteria (SRB) and diatoms as the representatives, oil-infused surface can steadily prevent the biofouling on stainless steel, showing the better performance than superhydrophobic surface for biofouling inhibition. Using epoxy resin as the artificial fouling agent, the pulling force to remove the glued solid on oil infused surface is much lower than that on bare stainless steel, illustrating oil layer acting as the separation cushion between fouling agent and underneath substrate.

Potential of synthetic chalcone derivatives to prevent marine biofouling

Biofouling represents a major economic, environmental and health concern for which new eco-friendly solutions are needed. International legislation has restricted the use of biocidal-based antifouling coatings, and increasing efforts have been applied in the search for environmentally friendly antifouling agents. This research work deals with the assessment of the interest of a series of synthetic chalcone derivatives for antifouling applications. Sixteen chalcone derivatives were synthesized with moderate yields (38–85%). Antifouling bioactivity of these compounds was assessed at different levels of biological organization using both anti-macrofouling and anti-microfouling bioassays, namely an anti-settlement assay using mussel (Mytilus galloprovincialis) larvae, as well as marine bacteria and microalgal biofilms growth inhibition bioassays. Results showed that three compounds (11, 12, and 16) were particularly active against the settlement of mussel larvae (EC50 7.24–34.63 μM), being compounds 12 and 16 also able to inhibit the growth of microfouling species (EC50 4.09–20.31 μM). Moreover, the most potent compounds 12 and 16 were found to be non-toxic to the non-target species Artemia salina (<10% mortality at 25 μM). A quantitative structure-activity relationship model predicted that descriptors describing the ability of molecules to form hydrogen bonds and encoding the shape, branching ratio and constitutional diversity of the molecule were implied in the antifouling activity against the settlement of mussel larvae. This work elucidates for the first time the relevance of synthesizing chalcone derivatives to generate new non-toxic products to prevent marine biofouling.

Prevention of Marine Biofouling Using the Natural Allelopathic Compound Batatasin-III and Synthetic Analogues.

The current study reports the first comprehensive evaluation of a class of allelopathic terrestrial natural products as antifoulants in a marine setting. To investigate the antifouling potential of the natural dihydrostilbene scaffold, a library of 22 synthetic dihydrostilbenes with varying substitution patterns, many of which occur naturally in terrestrial plants, were prepared and assessed for their antifouling capacity. The compounds were evaluated in an extensive screen against 16 fouling marine organisms. The dihydrostilbene scaffold was shown to possess powerful general antifouling effects against both marine microfoulers and macrofoulers with inhibitory activities at low concentrations. The species of microalgae examined displayed a particular sensitivity toward the evaluated compounds at low ng/mL concentrations. It was shown that several of the natural and synthetic compounds exerted their repelling activities via nontoxic and reversible mechanisms. The activities of the most active compounds such as 3,5-dimethoxybibenzyl (5), 3,4-dimethoxybibenzyl (9), and 3-hydroxy-3',4,5'-trimethoxybibenzyl (20) were comparable to the commercial antifouling booster biocide Sea-nine, which was employed as a positive control. The investigation of terrestrial allelopathic natural products to counter marine fouling represents a novel strategy for the design of "green" antifouling technologies, and these compounds offer a potential alternative to traditional biocidal antifoulants.