Search

Marine biofouling will bring a series of environmental and social problems, which restrict the development and utilisation of marine resources. Therefore, how to prevent biofouling has become a global issue. With the exploration of antifouling methods, bionic antifouling technology with environmentally friendly, broad‐spectrum, and long‐term advantages has gradually attracted people's attention. Inspired by the antifouling strategy of soft coral (Sarcophyton trocheliophorum), the silicone rubber (RTV‐2) with similar elasticity to coral skin was selected as the substrate. The composite structure of the upper transparent layer and the lower porous layer was prepared by simulating the structure of soft coral as the structural factors of the bionic antifouling coatings. Meanwhile, several organic antifouling components with high content contained in soft coral were added to the transparent layer and porous layer, respectively, as the component factors of biomimetic coatings. The bionic antifouling coatings, which are highly consistent with the coral structure, obtained the best antifouling performance under static and dynamic conditions. The above results provide new ideas for the synthesis of environmentally friendly bionic antifouling coatings. [ABSTRACT FROM AUTHOR]

• Parylene F has a wrinkled surface with low surface energy. • Parylene F can resist adhesion of bacteria and algae. • Parylene F has the potential in the marine antifouling applications. Parylene is an excellent barrier material used widely in many fields. In this work, parylene F was deposited on a polydimethylsiloxane substrate via chemical vapor deposition. We found that parylene F coatings could resist adhesion of bacteria and algae. The wrinkled surface topography, low surface free energy, and negative surface charge of parylene F facilitated an excellent antifouling performance. These findings provide a deeper understanding of parylene F, thereby expanding the scope of its application potential. Specifically, parylene F coatings show promise for marine antifouling applications. [ABSTRACT FROM AUTHOR]

Biofouling is a significant maritime problem because the growth of fouling organisms on the hulls of ships leads to very high economic losses every year. Inspired by the soft skins of dolphins, we prepared graphene oxide/silicone rubber composite membranes in this study. These membranes have low surface free energies and adjustable elastic moduli, which are beneficial for preventing biofouling. Diatom attachment studies under static conditions revealed that color has no effect on antifouling behavior, whereas the studies under hydrodynamic conditions revealed that the combined effects of color and elastic modulus determine the antifouling performance. The experimental results are in accordance with the "harmonic motion effect" theory proposed by us, and we also provide a supplement to the theory in this paper. On the basis of the diatom attachment test results, the membrane with 0.36 wt % of graphene oxide showed excellent antifouling performance, and is promising in practical applications. The results confirmed that the graphene oxide and graphene have similar effect to enhance silicone rubber antifouling performance. This study provides important insight for the design of new antifouling coatings; specifically, it indicates that lighter colors and low Young's moduli provide superior performance. In addition, this study provides a reference for the application of graphene oxide as fillers to enhance the composite antifouling performance. [ABSTRACT FROM AUTHOR]

The dispersivity of self-healing microcapsules plays a critical role in the self-repairing properties of coatings. However, resolving the aggregation phenomenon of self-healing microcapsules has been challenging due to their high surface energy. In this paper, we successfully developed magnetically responsive self-healing microcapsule (MS-TO@CA) and polyurethane (PU) coatings with biomimetic interface wet-adhesion patterned microstructures and realized the adsorption, automatic capture and dispersion of MS-TO@CA based on different patterned microstructure sizes, microparticle sizes and contents. COMSOL software was used to simulate the magnetic field design and distribution, and the magnetization phenomenon of the microstructure was analyzed. The optimal process for the preparation of a new type of magnetically responsive self-healing PU coating was proposed. Compared with the control group, the corrosion time of the metal under the action of the coating was delayed by 816 h, and the antifouling performance was improved by approximately 30 times. This work has guiding significance for prolonging the service life of metals and improving metal anticorrosion and antifouling. [Display omitted] • Magnetic PU coatings with bionic interface viscous microstructures were developed. • The magnetic divergence effect realizes dispersion of MS-TO@CA in the coating. • The corrosion time lag of the magnetically responsive self-healing coating is approximately 816 h. • The coating antifouling performance is improved by approximately 30 times. [ABSTRACT FROM AUTHOR]

Inspired by the structure and function of Salvinia molesta , a biomimetic antifouling film with double-scale microstructure antennae was designed and fabricated using silicone rubber-graphene composite materials (micro-SR-GN). The micro-SR-GN can absorb air bubbles underwater to wrap the whole antenna, forming a "bubble shield" that can act as an environmentally-friendly physical antifouling barrier. Due to its hydrophobicity and double-scale microstructure, micro-SR-GN has strong bubble adsorption function and can maintain bubbles stability at a certain fluid velocity (1.5 m/s). In static and dynamic antifouling experiments, micro-SR-GN exhibited excellent antifouling performance, which could resist the adhesion of both Gram-negative bacteria, Gram-positive bacteria and marine algae. These findings suggest that a promising platform could be achieved based on the physical antifouling strategy of "bubble shield" and show broad prospects in maritime industry. • Salvinia inspired biomimetic antifouling film can adsorb bubbles and maintain bubbles stable at a certain flow rate. • Bubble shield can effectively prevent the attachment of common fouling organisms, including bacteria and algae. • The antifouling strategy based on "bubble shield" is environmentally friendly. • The antifouling coating is prepared using a 3D printing template method, which is simple and convenient. [ABSTRACT FROM AUTHOR]

[Display omitted] • Imidazole-modified carboxygraphene was introduced into polyurethane coatings with disulfide bonds to successfully synthesize IAAC. • F-PUSS had outstanding anticorrosion function. • F-PUSS had excellent antibacterial and anti-algae functions. • F-PUSS showed distinguished self-healing function at 60 ℃. Marine corrosion and biofouling present significant challenges to maintaining maritime vessels and oceanic infrastructure. Developing coatings that integrate anti-fouling, anti-corrosion, and self-healing properties remains a critical issue. This study introduces imidazolium-modified carboxylated graphene (FCGO) into polyurethane coatings (F-PUSS) containing disulfide bonds to address this challenge. The incorporation of FCGO significantly enhances the mechanical properties of the coating, improving tensile stress by 40 % to 20.97 MPa. The barrier properties of FCGO also provide strong corrosion resistance, with |Z| 0.01Hz values an order of magnitude higher than the original samples, even after 15 days of immersion in sodium chloride (3.5 wt%). Additionally, F-PUSS retains corrosion resistance after repairs. The synergistic action of imidazole groups and graphene provides excellent antifouling performance with nearly to an alga rate of 100 % and an antimicrobial rate of 96 %. F-PUSS demonstrates remarkable self-healing capabilities, with a healing efficiency of 78 % after 48 h at 60 °C. This study provides valuable insights for designing multifunctional polymer materials with anti-fouling, anti-corrosion, and self-healing functions. [ABSTRACT FROM AUTHOR]

As permanently attached organism, soft corals can prevent fouling organisms from attaching to them through its anti-fouling mechanisms. In this paper, the antifouling mechanism of soft coral tentacles was revealed through the combination of numerical simulation and laboratory experiment. The results indicated that the interaction between tentacle structures and fluid medium affects the distribution and adhesion of bacteria. At the microscopic level, the boundary layer of low normal flow velocity forms a "water film" near the tentacles, preventing bacteria from approaching the tentacle surface. From the macro perspective, coral tentacles can disrupt the flow field through vortex streets, disrupt water flow stability, and make it difficult for bacteria to attach. The new discovery of bacterial movement and attachment behavior in the flow around a circular cylinder provides theoretical guidance for the design of antifouling surfaces. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Recent advances in integrated antifouling and anticorrosion coatings are reviewed. • The design principle in integrated antifouling and anticorrosion coatings is the combination of antifouling and anticorrosion units. • Advantages and limitations of integrated antifouling and anticorrosion coatings are compared and discussed. • Integrated antifouling and anticorrosion coatings should have environmental compatibility, applicability, and durability. With the rapid development of the marine industry, biofouling and surface corrosion of underwater equipment have become a major issue. Traditional antifouling or anticorrosion coatings with a single function cannot meet the current requirements. Recent developments in materials science and synthesis techniques have brought new opportunities and challenges in the field of integrated antifouling and anticorrosion coatings (IAACs). In this review, the mechanisms of biofouling and corrosion are introduced to help readers understand how their negative impact can be mitigated. Most of the IAACs are designed by combining antifouling and anticorrosion units into one coating, while several IAACs disobey the mentioned design principle since they have inherent antifouling and anticorrosion functions. This review highlights the recently developed IAACs, including polyaniline-based coatings, copper/amorphous carbon coatings, polydopamine/polymer brushes, amphiphilic polymers, endospore-loaded sol–gel coatings, hydrophobic/corrosion inhibitor coatings, nanocomposites, and bioinspired coatings. These emerging IAACs have been introduced in the last decade and may not yet be mature in practical applications and commercialization; therefore, their advantages and disadvantages are discussed. Finally, the future development of IAACs is discussed. We expect that this review will not only help readers understand the design principle of IAACs but also contribute to their development. [ABSTRACT FROM AUTHOR]

[Display omitted] • FD-EPU with FrGO and DCOIT were successfully prepared. • FD-EPU had excellent resistance to cavitation. • FD-EPU had outstanding anticorrosion properties. • FD-EPU had excellent antibacterial and anti-algae functions. • FD-EPU showed distinguished self-healing properties under NIR light. Erosion and fouling are important factors that affect the performance of power components of large cargo ships. Inspired by animal cartilage tissue, an epoxy modified polyurethane composite coating (FD-EPU) with reproducible self-healing properties was successfully prepared. FD-EPU was endowed with excellent resistance to cavitation, corrosion, and fouling due to the presence of functional reduced graphene oxide (FrGO) and 2-octyl-4,5-dichloroisothiazolinone (DCOIT). The introduction of FrGO with multiple hydrogen bonds into coatings increased the tensile strength of FD-EPU by 3.56 MPa and exhibited excellent cavitation resistance (with a mass loss of 4.7 mg under continuous cavitation for 60 h). In addition, the barrier effect of FrGO enabled FD-EPU to possess outstanding anticorrosion ability. After being immersed in 3.5 wt% NaCl for a duration of 15 days, the |Z |0.01Hz value of FD-EPU was found to remain at 9.18 × 109 Ω·cm2. The modification of epoxy resulted in FD-EPU coatings with improved adhesion by 53.5 % compared to non-modified coatings, with a bond strength of 23.8 MPa on stainless steel. The incorporation of DCOIT and FrGO endowed FD-EPU with good antifouling properties (removal of more than 97.5 % of bacteria and removal rate of microalgae up to 96.2 %). Furthermore, FD-EPU exhibited outstanding opto-thermal self-healing capability, with a self-healing efficiency of 61 % after 30 s of near-infrared light irradiation. This work provides a new inspiration for the protection of large cargo ship power components. [ABSTRACT FROM AUTHOR]

Cavitation, biofouling, and seawater corrosion are important factors that reduce the service life of propellers and other overcurrent components of ship. Herein, OH-PDMS was introduced into polyurethane and a series of hydrophobic polyurethane coatings (SiPU-X) with anti-cavitation, antifouling and anticorrosion functions were synthesized by a simple addition reaction. The chemical composition and microstructure of the prepared coatings were analyzed by means of FT-IR, SEM, and EDS, and it was found that the addition of OH-PDMS enhanced the degree of microphase separation of SiPU-X. The addition of OH-PDMS resulted in a large number of island structures of OH-PDMS on the coating surface. The SiPU-15 with the optimal microphase separation had better tensile strength of 12.33 MPa, excellent hydrophobicity (with a contact angle of 105.3°), hydrolysis resistance (with a hydrolysis rate of 0.26 %), and water repellency (with a water absorption of 2.21 %). More importantly, the weight loss (7.1 mg) of SiPU-15 was much lower than that of SiPU-0 (10.0 mg) under 60 h cavitation owing to the suitable microphase structure on the surface. In addition, SiPU-15 exhibited excellent fouling release properties and could remain in the ocean for 60 days without microbial adhesion. The |Z| 0.01Hz of SiPU-15 can maintain 3.33 × 107 Ω·cm2 after immersion in 3.5 wt% NaCl for 10 days. This work provides a heuristic perspective on the design of polymer materials with cavitation, fouling, and corrosion resistance performance. [Display omitted] • SiPU-X is prepared by introducing OH-PDMS into polyurethane. • The optimum degree of microphase separation is SiPU-15. • The weight loss of SiPU-15 is 7.1 mg under 60 h cavitation. • SiPU-15 is not attached to macroscopic organisms after 60 days of immersion in the real marine environment. • The log|Z| 0.01Hz of SiPU-15 can maintain 7.5 Ω·cm2 after immersion in 3.5 wt% NaCl for 10 days. [ABSTRACT FROM AUTHOR]

[Display omitted] • Repeatable self-healing polyurethane-FrGO composite coatings were prepared inspired by the self-healing principle of animal cartilage tissue. • Mechanical properties of composite coating were significantly enhanced with the introduction of 1 wt% of FrGO. • MPU-FrGO3 had outstanding anticorrosion function. • MPU-FrGO3 had excellent antibacterial and anti-algae functions. • MPU-FrGO3 showed distinguished self-healing under NIR light. Micro-cracking caused by the impact of gravel in the ocean is an important factor affecting the longevity of the integrated antifouling and anticorrosion coating. Inspired by the animal cartilage tissue, a series of polyurethane composite coatings (MPU-FrGO) with repeatable self-healing functions were successfully prepared. MPU-FrGO are endowed with excellent antifouling and anticorrosion ability because they contain functional reduced graphene oxide (FrGO) and 2-methyl 4-isothiazoline 3-ketone (MIT). As animal cartilage tissues, two-dimensional structure of FrGO forms hydrogen bond crosslinking and chemical crosslinking with polyurethane in MPU-FrGO. The super strong spatial network endows MPU-FrGO3 (the amount of FrGO added is 1 wt%) with excellent mechanical properties and strong self-healing ability. Its stress (35.6 MPa) and strain (861%) is far more than that of PU-FrGO0 (27.2 MPa and 762%). MPU-FrGO3 showed exceptional self-healing performance, and the self-healing efficiency could reach 91% (91% of initial stress) after 15 min of NIR irradiation; the self-healing efficiency of five cycles can reach more than 83% (83% of initial stress). The |Z| 0.01Hz of MPU-FrGO3 can still maintain 3.34 × 108 Ω·cm2 after immersed in 3.5 wt% NaCl for 15 days because of the excellent barrier performance of FrGO. Owing to the excellent antibacterial and anti-algal functions of FrGO and MIT, the antibacterial ability and algae inhibition coverage ability of MPU-FrGO3 were 99.5% and 97.1%, respectively. The work provides a heuristic perspective for the design of polymer materials with anticorrosion, antifouling, and self-healing. [ABSTRACT FROM AUTHOR]

Silicone rubber (SR) based coatings with remarkable antifouling performances have received tremendous interests due to their prominent merits of environmental adaptability, stability, non-toxicity. However, it still remains a great challenge to fabricate SR-based antifouling coatings with both high mechanical properties for the bulk coating and high adhesion properties to substrates. Herein, a dual-functional SR-based coating with both antifouling and anticorrosive performances was developed by incorporating polyurethane (PU) chains into the SR framework to form SR/PU interpenetrating polymer networks (SR/PU IPNs), to maintain its high adhesion to metal substrate without compromising surface antifouling properties. By adjusting the mass ratio of SR and PU components, the adhesion of the SR/PU IPNs to the substrate as well as its mechanical properties can be remarkably improved. Compared with the pristine SR, the SR/PU 75 IPNs possessed the optimized mechanical properties, with the increases in the Young's modulus and compression modulus, by ~312 % and ~289 % respectively. Additionally, the adhesion strength of the composite was increased by 369 %. Owing to the synergistic effect of SR/PU IPNs, the SR/PU 75 IPNs realized synchronous enhancement of antifouling and anticorrosion performance. After 28-day immersion in 3.5 % NaCl solution, the SR/PU 75 IPNs coating was tightly bonded with the substrate, and exhibited a maximum |Z| 0.01Hz value of 1.254 × 108 Ω·cm2.This proposed dual-functional SR/PU IPNs coating may provide a novel strategy for the future development of marine instruments and equipment, where both strong mechanical performances and high antifouling/anticorrosion performances are acquired. [Display omitted] • A novel dual-functional coating based on SR/PU IPNs was prepared by simultaneous interpenetration method. • SR/PU IPNs coating remarkably enhanced adhesion strength and mechanical performances. • SR/PU IPNs coating exhibited excellent antifouling and anticorrosion performances. • SR/PU IPNs coating provided a promising strategy for marine application development. [ABSTRACT FROM AUTHOR]

• Parylene F demonstrated antiadhesion and antibacterial properties. • Parylene F exhibited a good light transmittance (> 81 %). • Parylene F had an excellent biocompatibility. As an excellent barrier material, parylene has been widely used in plenty of fields. However, conventional parylenes cannot endure medical sterilization procedures, including high-temperature sterilization and ultraviolet disinfection, which restrict their medical applications. A new parylene member, Parylene F, overcomes the above drawbacks and shows potential in medical applications. In this work, parylene F (type AF4) was deposited on two polydimethylsiloxane (PDMS) substrates through chemical vapor deposition (CVD) method, and the thickness of parylene F was 1 μm (PDMS-PF-1) and 5 μm (PDMS-PF-5), respectively. For the first time, we investigated the antifouling property and biocompatibility of parylene F. We found an interesting phenomenon that parylene F demonstrated dual-action antifouling activities—antiadhesion and antibacterial. For gram-negative bacteria Escherichia coli , the fouled area to the total area ratios on PDMS-PF-1 (0.69 ± 0.25 %) and PDMS-PF-5 (0.5 ± 0.1 %) were significantly lower than that on the pristine PDMS (6 ± 0.77 %). The antibacterial ratios (dead/total bacteria) of PDMS-PF-1 (45.49 ± 9.58 %) and PDMS-PF-5 (45.3 ± 8.8 %) were higher than that of the pristine PDMS (28.12 ± 3.26 %). Similar results were also observed in the tests against gram-positive bacteria Bacillus subtilis. The synergistic effect of antiadhesion and antibacterial characteristics endowed the surface with excellent antifouling properties. These results indicated that the thickness of parylene F had a close relationship to its antiadhesion performance, while not affecting the antibacterial activity. Additionally, this study revealed that parylene F exhibited good light transmittance (PDMS-PF-1 > 83 % and PDMS-PF-5 > 81 % in the visible wavelength) and excellent biocompatibility (relative cell viability > 86 %). These excellent properties mean that parylene F can act as a potential candidate for medical and related applications. [ABSTRACT FROM AUTHOR]