ABSTRACT
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.
Keywords:
Nanomaterials
Antifouling
PDMS composites
Environment-friendly
Marine biofouling
1. Introduction
Marine biofouling, an undesirable accumulation of marine organisms on the surface of submerged structures, has caused great harm to marine ships and marine facilities [1]. These damages can be summarized into two aspects: economic loss and environmental damage. Marine biofouling will make the surface of the ship rough, leading to the increase of friction resistance (up to 60%), further resulting in the reduction of ship speed and the corresponding increase in fuel consumption (even up to 40%) [2]. Schultz et al. pointed out that the thin slime on the hull surface alone can cause 21% energy loss, and the energy loss caused by highly calcified fouling organisms is even as high as 86%, and severe biofouling will inevitably lead to frequent docking maintenance, and the overall economic loss is as high as billions of dollars [3–5]. The high fuel consumption caused by biofouling leads to the emission of additional CO2 and SOx, causing environmental pollution and acid rain formation, and the production of fine dust particles has a negative impact on the health of humans and other living organisms [6]. Marine biofouling cause blockage of fishing nets, reduced service life, increased presence of bacteria, and affect the development of aquaculture [7,8]. The migration of non-target species will bring biological invasion and seriously affect the local ecological environment [9,10]. These influences promote the research of marine antifouling (AF) mechanism and AF strategy, and the most effective way is to apply marine AF coatings.
In the field of marine AF, to prevent the attachment of biofouling to the surface of equipment and instruments by efficient and environmental protection methods is a key concern [11]. Nowadays, the use of biocide AF coating is the main protective measure, but the heavy metals or organic biocides contained in the system often destroy the marine ecological environment [12]. Therefore, the environmental protection needs to be considered, making environment-friendly AF materials gradually become the development focus of marine AF coatings [13]. Many different polymers have been developed and used, such as polyurethane [14], polyurea-polysiloxane [15], polyacrylates [16], organic fluoropolymers [17], epoxies [18], polyvinyl alcohols [19] and polyacrylamides [20]. Amongst these materials, polydimethylsiloxane (PDMS) is used as a non-stick AF coating, allows to make flexible structures, with hydrophobic surfaces and low surface energy, thus can be functionalized well in fast cruising situation [21–23]. The possible anti-fouling mechanism is described as follows: First, the uniformly smooth PDMS coating presents weak non-specific interaction forces to the surface coating and induces a lower bacterial adhesion hydrogen bond, which leads to the inability of bacteria to adhere stably to the coating surface; Second, the interaction between dextran abundant in Marine cells and water (°612.43 - 100.34 kJ/mol) is much greater than the interaction between dextran and the surface coating (°72.80 - 51.66 kJ/mol), so dextran is difficult to attach to the PDMS coating [24]. However, these characteristics also lead to weak adhesion between PDMS coating and substrate, poor mechanical properties and low static AF ability, which limits its practical application in the marine field [1]. Therefore, without reducing the AF performance, it is of particularly importance to address and solve these problems.
Nanomaterials possess many remarkable properties, and depending on their structure and sizes they present properties known as quantum size effect, surface effect, volume effect and macro quantum tunnel effect of nanoparticles (NPs). All these properties, make nanomaterials to have a wide range of applications in various fields, such as biopharmaceutical [25], renewable energy [26], sensors [27], water treatment [28], and AF coatings [29]. In addition, some nanomaterials also have the advantages of photocatalysis, aging resistance and antibacterial properties, thus providing multifunctional candidates for solving the problems for PDMS coatings. However, how to make nanofillers in order to enhance the AF ability of PDMS is another problem to be addressed in detail, the type, shape, size, dispersion and compatibility of nanomaterials with PDMS will have significant effects on the AF, anti-corrosion, self-cleaning and antibacterial properties of coatings. In the last decade, a great deal of work (see Fig. 1), has been done to study in detail the enhancement effects of different nanomaterials (such as carbon materials, precious metals, metal oxides, etc.) in the marine AF field.
Economy, environmental friendliness and long-term stability are the basic direction of marine AF coatings in the future, nanomaterialenhanced PDMS composite coatings is one of the important research directions of novel AF materials. In this review, we introduced the research achievements and latest progress of PDMS composite coatings containing nanomaterials in detail, discussed the characteristics of different nanomaterials composite PDMS coatings and the advantages and key problems in preventing marine biological fouling, and finally proposed the potential application, challenges and future development path of nanomaterials composite PDMS coatings. This review aims to provide basic guidance for the development of fouling release AF coatings.
2. Marine biofouling
The formation of marine biofouling on artificial surfaces has undergone a complex process, involving more than 4000 species of fouling organisms [30]. According to the type of fouling substance, it can be divided into conditioning membrane, microbial membranes and large fouling biological community. The colonization of them involves five successive processes of adsorption, immobilization, consolidation, microfouling, and macrofouling, a schematic overview is provided in Fig. 2 [31].
Adsorption of organic molecules (polysaccharides, proteins, glycoproteins, etc.) and other inorganic compounds immediately after immersion, forming the conditioning membrane [32].
Migration and immobilization of microorganisms (bacteria, saccharomyces, diatoms, etc.) to artificial surfaces.
Microorganisms accumulate to the substrate consolidated and secrete extracellular polymeric substances (EPS) to form microbial membranes, which accelerates the formation of marine fouling [33,34].
Glycoproteins secreted by multicellular organisms (algae spores, fungi, protist larvae, etc.) form microfouling biological layer through chemical cross-linking reactions.
Attachment, growth and interaction of marine macrofouling organisms (barnacles, mussels, algae, etc.) form large fouling biological community.
The whole process takes only a few days to complete, and the unprotected surface is normally covered by marine life within a few months [35]. Therefore, biofouling is almost inevitable, any materials immersed in seawater will be affected by biological fouling, and the current AF methods are mainly to interfere with the formation of microbial membrane to achieve the AF purpose.
3. Antifouling strategies based on nanomaterial-enhanced PDMS coatings
Nanomaterial-enhanced PDMS coatings is one of the development trends for the design of environmentally friendly, stable and reliable selfcleaning coatings in the future due to its non-toxic and non-leaching characteristics. According to literature research, nanomaterial-enhanced PDMS AF coatings can be divided into three types, namely, fouling release, fouling resistance and fouling degradation. The former two materials resist bacterial and algae adhesion by forming hydrophilic surface and surface free energy barrier; and the latter is to kill bacteria by adding antibacterial agents or photocatalysis. Specifically, nanomaterialenhanced PDMS coatings can be divided into carbon nanomaterial, metallic nanoparticle, amphiphilic polymer, natural antibacterial agent, photocatalytic material and hydrogel material. Fig. 3 presents a schematic overview of the before mentioned strategies and representative active ingredients used for PDMS-based antifouling coatings.
3.1. PDMS AF coating containing carbon nanomaterials
3.1.1. Carbon nanotubes
Carbon nanotubes (CNTs) have the potential to be blended with different matrices to prepare nanocomposites, and introduce improved physicochemical and structural properties when compared to polymer matrices. The improved physicochemical and structural properties are thanks to CNTs unique structural features and antibacterial activity (possible mechanisms include cell membrane damage [36] and oxidative stress [37]) [38–40]. Several studies have confirmed that CNTs modified PDMS has a low degree of biological pollution and can resist fouling adhesion [41]. The difference in surface structure and increased hydrophobicity affected directly the dynamics of colonization and succession of pioneer biofilm communities, especially early eukaryotic communities [42].
The physical inclusion of 0.1 wt% CNTs in the PDMS matrix can greatly improve the AF performance under static immersing, mainly because the wettability of PDMS resin and the significant changes in the surface nanostructure greatly promote the regulation of the initial colonization of natural microorganisms in the natural biofilm and the enhancement of the disturbance effect [43]. The introduction of hydrophobic CNTs in PDMS can increase the water contact Angle (WCA) of the coating, reduce the roughness, surface energy and elastic modulus, and improve its AF ability [44]. The introduction of multi-walled carbon nanotubes (MWCNTs) and fluorinated MWCNTs into PDMS substrates can significantly improve the mechanical and AF properties of the coating [45]. The minimum critical surface energy of fluorinated MWCNTs was 14.67 mJ/m2 and their modulus and tensile strength are between 0.7–1 MPa and 0.2–0.27 MPa, respectively. The adhesion strength of false barnacles on the coatings with MWCNTs and fluorinated MWCNTs decreased by 47% and 67%, respectively, compared to that of the unfilled sample, indicating that the addition of MWCNTs improved the anti-adhesion ability of coatings, and the fluorination on the surface of MWCNTs had a synergistic effect on the anti-adhesion ability of composite coatings. Combining the antibacterial properties of MWCNTs and the low surface energy of PDMS, Wang et al. designed and synthesized a self-polishing coating with controllable hydrolysis rate and surface energy by chemical grafting method. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) against Escherichia coli and Staphylococcus aureus were 8 μg/ml and 32 μg/ml respectively [41]. The AF method based on the functionalization of CNTs can improve the AF ability of coatings by enhancing mechanical properties of materials, which provides new ideas, new materials and new methods for the removal of marine fouling organisms.
The AF mechanism of CNTs/PDMS composites has been studied for several years, but the specific mechanism is still unclear. Wang et al. studied the potential effect of CNTs in MWCNTs-OH/PDMS composites on the biomechanical colonization dynamics of early biofilm-forming bacterial communities [46]. The AF performance of PDMS coatings with 0.1% CNTs was greatly improved, the diversity of early bacterial communities on its surface was 2.09 - 0.44–2.45 - 0.22, and the number of dominant species increased to (0.093 - 0.021–0.160 - 0.088), which was much lower than that of control (2.56 - 0.26 and 0.088 - 0.027). So, the surface of PDMS/CNTs may have a weak ability to inhibit the biological colonization of early adherent bacterial communities in natural biofilms. Three chlorinated rubber-based anticorrosive coatings (coating C0) were prepared by the same method, and PDMS composites (PF) were filled with original PDMS (coating P0) and carboxy-modified MWCNTs [47]. After 260 days of static ocean immersion, the PF coating showed excellent oxidation resistance, fewer pollutants and a smooth surface. Based on the eukaryotic Single-stranded Conformation Polymorphism (SSCP) map, the biodiversity and abundance of C0 surface were (2.71 - 0.21 and 123 - 30) higher than that of P0 surface (2.48 - 0.22 and 91 - 19) and PF surface (1.97 - 0.45 and 79 - 14) respectively (Fig. 4a). This proves that PF is a promising material for the control of biofilms in the future application of biological pollution control.
To explore the common structural characteristics of biofilm bacteria (PSB) community composition, distribution and diversity on the pioneer surface of PDMS coating, Sun et al. [48] studied the effect of adding MWCNTs to PDMS nanocomposites on biofilm community structure, and compared the number of species forming natural biofilm between original PDMS and PDMS/CNTs. About 85% of the microorganisms forming biofilms on the surface of PDMS were proteobacteria, followed by cyanobacteria and bacteroidetes. However, the proportion of Proteus bacteria in biofilms formed on PDMS/CNTs was about 66%–73%, much lower than that on the original PDMS (Fig. 4b). The results show that CNTs can inhibit the larval stage of microbial membrane and large polluting organisms. The composition and diversity of PSB communities on different PDMS substrates were similar, but their relative abundance and distribution were different. Further studies can be conducted using genomic sequencing in the future to understand the common functions of PSB communities on different PDMS-based coatings.
3.1.2. Graphene materials
In addition to CNTs, carbonaceous nanomaterials also include graphene-related materials such as Graphene, Graphene oxide (GO), rGO and graphite carbon nitride (g-C3N4). Graphene is an ultra-thin twodimensional (2D) lamellar carbon material, which has high specific surface area, excellent photocatalytic performance, electrical conductivity, corrosion resistance, environmental protection and mechanical properties to become a highly efficient nanofiller for medicine, biology, marine AF and anti-corrosion [49,50]. Cell damage caused by sharp edges of graphene and oxidative stress induced by reactive oxygen species (ROS) make graphene materials exhibit good antibacterial and anti-adhesion properties [51]. Based on the above advantages of graphene and PDMS matrix, graphene-based PDMS composites can be prepared for the manufacture of antimicrobial and antifouling coatings with high mechanical properties, friction resistance and low cost [52]. Cavas et al. found that carbon NPs can improve mechanical properties such as tensile strength and elongation of pure PDMS, thus affecting the ability of dirt release by adding MWCNTs and GO fillers to the PDMS matrix [53]. Because graphene is easy to agglomerate in a polymer matrix, an aerogel technology was introduced to prepare graphene aerogel based PDMS composite material to overcome this problem. The composite material showed good compatibility and mechanical strength. The loose aerogel graphene structure prevented the agglomeration of graphene in PDMS. The results of cytotoxicity evaluation in Fig. 5 showed that the PDMS coating containing only 1 wt% graphene had low toxicity and good biocompatibility. The antibacterial activity of PDMS coating containing only 1 wt% graphene was over 88% [54]. This conclusion proves the reliability and effectiveness of aerogels for PDMS antibacterial coating, and has a broad application prospect in future biomedicine, marine AF and other fields.
In order to improve the limitation of uneven dispersion of graphene nanosheets in PDMS, Hu et al. used the negative pressure assisted mixing method to prepare graphene-based PDMS composites, which showed superior tensile strength, thermal stability and antibacterial activity than traditional PDMS, and had application potential in biomedical, Marine AF and other fields [54]. Ramezanzadeh et al. found that an epoxy resin loaded with 0.4 wt% Zr on a metal-organic skeleton (MOF) can improve the bonding strength and hardness of the epoxy coating [55], and the corrosion protection efficiency of the epoxy resin containing ZIF-70 modified GO nanosheets can be increased by 8% [56]. Combined with the low surface energy and anti-fouling characteristics of PDMS, The composite obtained by introducing ZIF-8 modified GO nanosheets into PDMS materials showed excellent anti-corrosion and AF ability, and there were only a small amount of fouling organisms on the surface after 3 months of immersion in the growing season of Qingdao Port [57]. Boehmite and Graphene oxide (GO) nanomaterials (GO-ɤ-AlOOH) were synthesized using one-step ultrasonic method and then used as nanofillers to prepare PDMS composites (Fig. 6) [58]. The antibacterial activity of PDMS/GO-ɤ-AlOOH nanorod composites against different strains for 30 days was better than that of PDMS/GO nanorod composites. The lowest biodegradation rate of PDMS/GO-ɤ-AlOOH nanorod composites with 3 wt% addition was 1.6%, and the Gram-negative antibacterial rate could reach 97.94%. The composite has long-term AF properties after 45 days of immersion in natural seawater.
At present, although CNTs and graphene have been embedded into PDMS for the enhancement of mechanical properties, the antibacterial effect still needs further improvement; besides, the pioneer colonization dynamics and species diversity on these composites still require deep investigation, in different seasons, different sea area, etc. In addition to simple binary PDMS composites containing CNTs, MWCNTs or graphenerelated carbon NPs, multi-component PDMS composites containing carbon nanomaterials such as PDMS modified MWCNTs/ZnO superhydrophobic composite coatings [59], silicon oil MWCNTs/PDMS coatings [60], GO/ZnO PDMS coatings [61] and GO/Magnetite PDMS coating [62], has also been extensively studied. The introduction of silicone oil on the basis of hydroxylated MWCNTs reinforced PDMS coating can further reduce the surface energy, and the anti-pollution ability can be adjusted by controlling the type, content, leaching rate, hydrophobicity and surface energy of silicone oil, which shows a good development and application prospect [60]. The marine AF performance of multi-component PDMS composites will be described in detail in the following chapters.
3.2. PDMS AF coating containing metallic nanoparticles
The application of inorganic NPs in AF coatings can effectively improve the mechanical properties and antibacterial properties of coatings [63], and achieve the removal or anti-adhesion ability of various fouling organisms (microbial membrane, bacteria, barnacles, mussels, etc.) in the ocean [64]. Metallic and their oxide NPs (Ag, ZnO, TiO2, Cu2O, etc.) and hybrid metal-metal oxide, as well as hybrid carbon-metal oxides nanostructures were the most commonly used systems for the inhibition of biofouling [65]. Among them, ZnO and TiO2 have high photoactivity, and their AF mechanism is based on exposure to UV/visible light irradiation, resulting in electron transfer from valence band to conduction band and electron-hole pair [66]. When separated, the photoexcited formation of •OH radicals effectively reduces oxide adsorption on its surface. Both free radicals and anions can react with pollutants to degrade or transform them into less harmful by-products, which are the most commonly used nanomaterials to resist biological fouling and enhance biodegradation (Fig. 7a) [67,68]. Such semiconductor materials that can carry out photochemical reactions under light conditions are also called photocatalyst materials (Fig. 7b) [69]. Table 1 summarizes the effects of several metal oxide modified PDMS materials on mechanical properties and AF ability, and the specific investigation results are as follows.
3.2.1. Silver nanoparticles
Silver ions (Agþ) has strong antibacterial activity, and its contact reaction can cause the destruction of microbial common components or dysfunction [70]. When a small amount of Agþ reach the microbial cell membrane, because the latter is negatively charged, they are firmly adsorbed by Coulomb gravity. Agþ penetrate the cell wall into the cell and react with sulfydryl (-SH) to solidify the protein, destroy the activity of cell synthase [71], and the cell loses the ability of division and proliferation and dies [72]. Therefore, silver nanoparticles (AgNPs) and other functional NPs have excellent AF performance.
The use of non-toxic method to control fouling adhesion is one of the key research directions of marine AF materials. The composite coatings of PDMS containing AgNPs is a hotspot in non-toxic AF coatings, but it is often complicated to obtain the coating with strong hydrophobicity and outstanding mechanical properties without leaching AgNPs. Sol-gel synthesis of spherical AgNPs into the PDMS matrix to solve this problem has played a huge advantage [73]. Compared with the original PDMS, the water contact angle of 0.1% AgNPs/PDMS coating increased from 102° to 148°, the surface free energy decreased from 23.91 to 12.4 mJ/m2 , and they have high elasticity and flexibility. After 30 days of biodegradability test, 0.1% AgNPs/PDMS had almost no fouling biological attachment. After immersing 12 months, the small amount of microorganisms adhering to the edges can be easily removed by hydrodynamics, with renewable self-cleaning properties. However, the agglomeration of metal NPs in the PDMS matrix still exists, so it is possible to obtain more compatible composites by improving the preparation technology.
The AgNPs enhanced PDMS coating has obvious antibacterial, antialgal and inhibition of marine biofouling adhesion, but the release of heavy metal ions still bring serious environmental pollution problems. Therefore, PDMS composites coating containing AgNPs can be prepared by structural design and improved synthesis method, and the release of Agþ can be strictly controlled, so that it can only maintain excellent mechanical properties, hydrophobic properties and AF properties.
3.2.2. Copper and their oxide nanoparticles
Copper (Cu) is believed to have antibacterial properties as far back as the Phoenician era, with a low toxicity, low price point, is a long history of fungicide. The development of nanotechnology has enabled different forms of Cu particles (macro, micro and nano) and their oxides (CuO, Cu2O, etc.) to be applied to marine antibacterial and AF fields. Chapman et al. proved that Cu NPs had a more significant AF effect by adding three different forms of Cu particles to the PDMS matrix (protein adsorption capacity reached 0.12%, the lowest biological mucus was 0.11 - 0.02AU) [74]. However, it is still a difficult problem to ensure the low marine fouling, low biological settlement and controlled release of Cu and its derivatives.
Jiang et al. introduced copper nanowires with a uniform network into the PDMS substrate using deposition technology to control the release of copper ions, and found that the release rate during 50 days of seawater immersion has a linear relationship. When the copper nanowires content is greater than 50 μg/m°2 , the barnacles on the composite coating almost do not settle; when the copper nanowires content is less than 25 μg/m°2 , the settlement rate on the composite coating is lower than 10% and does not cause barnacles to die, showing environmental friendliness [75], indicating the direction for the future application of copper and its derived NPs in marine AF. El-Safty et al. add Cu2O nanocube (70–110 nm) synthesized.at room temperature into the PDMS matrix to prepare a nanocomposites, showing outstanding dispersion and AF performance [76]. When 0.1% Cu2O NPs was added, the average tensile modulus and average dynamic stress of composite coating are 3.6 - 0.5 MPa and 1300 - 185 Pa, respectively. The water contact Angle of the coating increased from 102° to 130°, the surface free energy decreased from 23.06 mN/m to 16.39 mN/m, and the microbial adhesion rate decreased. However, the unstable release rate of Cuþ/Cu2þ still exists in the AF coating, so it is necessary to further study the nanostructure to achieve durable and stable release of AF agent from the coating.
In order to reduce the fouling biological adhesion of PDMS coating under static condition, cetyltrimethylammonium bromide (CTAB) coated (0.05 and 1.0 M) CuO nanoparticles were successfully synthesized by Alwar et al. [77], via a wet chemical precipitation method and added into PDMS to prepare a novel PDMS/CuO nanocomposite. Based on the rough surface area and metal ion release of the nanofillers, After 90 days of exposure, the polluted biomass in coastal waters decreased from 9 kg m°2 (PDMS) to 0.6 kg m°2 (PDMS@CuO-(0.05 M CTAB)). The surface area coverage of organic pollutants decreased from 98.3 - 0.6% of PDMS to 36.8 - 2.34% of PDMS@CuO-(0.05 M CTAB) nanocomposites. It was found that CuO NPs coated with 0.05% CTAB had better AF performance. In the same way, CuO NPs were introduced into the silicone matrix [78]. The biofouling of coastal waters for 90 days showed that the adhesion amount of microalgae on the surface of PDMS and CuO nanocomposites was 1.3 x 103 cm°2 and 1.76 x 102 cm°2 , respectively. The corresponding biocontamination load and surface area were reduced from 10.6 - 1.5 kg/m2 and 89.6 - 7.96% to 1.6 - 0.22 kg m-2 and 27.5 - 4.5% respectively, achieving the best AF ability under static conditions (Fig. 8).
The above studies indicate that the AF performance of the organosilicon coating can be improved by the addition of Cu/CuO/Cu2O NPs at low dosage, mainly through the high leaching rate of these biological killing NPs and the high rate of entering the cell membrane, as well as the production of Reactive Oxygen Species (ROS) and the high oxidative stress to the cell membrane. Although these biocide AF coatings have a smaller environmental impact than organotin coatings, their application remains problematic due to their toxicity to several marine species, and further research on its release performance or environment-friendly AF agent substitutes is needed in the future.
3.2.3. ZnO nanoparticles
ZnO NPs have high inhibition effect against both aquatic prokaryotes (bacteria) and eukaryotes (microalgae, barnacles, bryozoans, etc.), with highly photoactive, antibacterial, self-cleaning, mechanical properties, and are usually used to construct super hydrophobic coatings, and are widely used in marine AF materials [79].Because of their special hexagonal lattice structure, ZnO NPs can be easily assembled in various shapes, and various morphologies such as sheet, rod, wire, tube, ball and flower can be obtained by different preparation methods. The change of microstructure will also significantly affect the AF ability of the composite. However, no matter how the morphology of ZnO nanoparticles is changed, our goal is to obtain hydrophobic, antibacterial, mechanical properties, strong anti-fouling materials.
In order to solve the problem of low hydrophobicity and poor selfcleaning ability of the materials, Nano-ZnO was introduced into the polydimethylsiloxane matrix by Li et al. PDMS/ZnO composites were prepared and sprayed on the surface of Q235 carbon steel [80]. By comparing the surface wettability of the materials, the WCA of ZnO/PDMS composites increased from 114 - 1.7° to 158.3 - 1.7°, and After 30 days of immersion in pulp, milk, tea and soybean milk, the WCA value of the coating remains at 152.3°~156.9°, achieving the superhydrophobic property, and the coating still maintains self-cleaning ability (Fig. 9a). Epoxy resin/flower-like ZnO/PDMS (ER/F-ZnO/PDMS) composite coating prepared by the layer spraying method by Bao et al. [81] showed strong hydrophobic ability, and its contact Angle reached up to 161.3°. After 40 wear tests, the WCA was still greater than 150°, showing high friction resistance. The WCA value after 40 h UV irradiation was maintained at about 160°. The coating was soaked in different liquids (dyeing water, coffee, tea, milk, cola, hydrochloric acid, alkaline solution, etc.). The results showed that the surface of the aluminum plate treated by ER/F-ZnO/PDMS coating was clean and had good anti-fouling performance. This nanomaterial has outstanding advantages in flower structure design, but it can be further studied in the field AF and microbial adhesion experiments in the ocean to further study the AF mechanism of ZnO nanomaterial. But unfortunately, the above studies have not studied the antibacterial ability and anti-fouling ability of the composite coating for actual characterization and analysis, limited to the description of hydrophobicity and self-cleaning ability, not sure of its anti-fouling ability of bacteria, diatoms, barnacles and other fouling organisms in the ocean. In the future still need to further study the PDMS coating containing ZnO nanofillers resistance to adhesion of bacterials, mussels and other marine polluting organisms.
Selim et al. prepared ZnO nanorods (NRs) with a diameter of 30~40 nm by an improved wet chemical method, and then dispersed 0.05–5% ZnO NRs in PDMS solution for anionic ring-opening polymerization to synthesize PDMS/ZnO NRs composites [82]. In addition to showing strong hydrophobicity (water contact Angle up to 158° and free energy down to 11.25 mN/m), the bioadhesion rate of the material soaked in water for 1 month (no bioadhesion detected) was also significantly better than that of pure PDMS (bioadhesion rate: 18%) After soaking in static seawater for 6 months, only a small amount of biological mucosa existed on the surface of the coating (Fig. 9b), which achieved the best anti-fouling performance. The above research proves that ZnO NPs have super hydrophobic and anti-fouling bioadhesion properties, and can be used as a potential substitute for marine AF coatings.
Based on the effect of ZnO on the enhanced mechanical properties and AF properties of PDMS coating, Shatakshi et al. [83] further prepared multifunctional epoxy ZnO PDMS nanocomposite coatings by in-situ polymerization (Fig. 9c). The results show that the maximum contact angle of the nanocomposite coating is 123.5° and the surface energy is 19.75 mN/m. Compared with epoxy composite coatings, when the ZnO NPs content is 1 wt%, the wear loss rate is 3.3 mg/1000 times, the wear index is 33.75 mg/800 times, the bond strength is 3.31 MPa, the wear resistance and pull off adhesion are increased by 34.7% and 150.7% respectively. The maximum hardness of the coating is 65.75 MPa. The 8-month static AF experiment shows that the nanocomposite coatings can effectively inhibit the accumulation of marine bacteria. The nanocomposite coatings has excellent thermal properties, mechanical properties, AF properties and antibacterial properties, and can be a new kind of integral coating material for marine applications.
In addition to pure nanoparticles, amphiphilic polymer modified ZnO also showed excellent AF performance. To verify its mechanical properties and AF ability, ZnO NPs modified with Perfluorodecyltrichlorosilane (FDTS) were prepared by Arukalam et al. [84], and mixed with PDMS. Different amounts of coatings were prepared on glass and Q235 steel substrates by rotating coating technology. By comparing the mechanical properties and surface wettability, it is found that the adhesion of unmodified zinc oxide nano-coating is 1.84 MPa, and the adhesion of FDTS coating can be increased to 2.41 MPa, and the fracture strength of the original coating increases from 0.05 MPa to 0.18 MPa. The maximum contact angle and surface energy of the modified coating are 128.45 - 0.74° and 26.59 - 0.55 mN/m respectively.
The main AF mechanism of ZnO is ROS generation. These results indicate that ZnO NPs composite PDMS coating can effectively prevent marine microscopic and macroscopic fouling under static conditions, and can significantly improve the mechanical strength and surface properties of the coating. However, ZnO NPs dissociates slowly in water and releases Zn2þ. Due to the photocatalytic action, the dissolution of ZnO NPs in water increases, resulting in the service life of Zn2þ limited its application in AF field.
3.2.4. TiO2 nanoparticles
TiO2 is an excellent photocatalyst. Because of its inert, non-toxic (to the environment and human beings), low cost, strong oxidation ability, good optical transmittance, light corrosion resistance, chemical resistance, AF activity and precursor availability [85]. Its coating film has photoinduced super hydrophilic and self-cleaning characteristics, which can modify the coating surface to provide considerable mechanical enhancement and surface wettability [86].
In order to improve the fouling release performance of the composite coating, the wettability of the composite coating was investigated. Using a simple blending method PDMS/Nano-TiO2 Composite coatings are proposed by Ding et al. [87], the coating has a stability of more than three months, the photocatalytic activity has been achieved by the chemical interaction (the newly formed Ti-O-Si bond) between TiO2 and PDMS,
and the self-cleaning function has been achieved by decomposing the adsorbed organic stain. It is found that the original coating has a water contact angle of 113°, and the water contact angle decreases to 111° after the addition of TiO2 NPs. The water contact angle remains at 110° after 60 h ultraviolet light (UV) irradiation. The hydrophobicity does not change significantly. Similarly, based on its wettability on the surface, using the sol-gel technology to synthesize and control the crystal size, rutile TiO2 nanospheres with the advantage of [110] crystal face were synthesized by Selim et al. [88], and TiO2 nanofillers with different concentrations were incorporated into the silicone nanocomposites for performance comparison. The experimental results show that the PDMS/0.5% TiO2 nanocomposite reduces the contact angle to 10° after UV irradiation, has super hydrophilicity, and the surface energy increases to 144.49 mJ/m2 , which inhibits the dirt adhesion on the hull surface. The mechanical test shows that the tensile modulus of the composite coating with 0.5% addition is lower than 4 MPa and the impact capacity is 10 J, which is much higher than twice that of the original coating. After penetrating and bending on the 5 mm cylindrical spindle, no invasion of the tested coating was found under the magnifying glass, and no visible adhesion defects were produced during the cross cutting test. The 360-day field seawater test showed that the 0.5% composite coating achieved anti-fouling capability of both small scale and large scale (Fig. 10). However, TiO2 nanomaterials only play a photocatalytic effect under the condition of visible light irradiation, and are mostly used in the degradation of organic dyes in industrial wastewater, but rarely used in marine AF coating, so it is necessary to further study its AF mechanism.
The above research indicates that TiO2 NPs play a key role in improving the AF and surface wettability of organosilicon. Nanocomposite coatings loaded with TiO2 NPs exhibit oxidation and reduction properties when exposed to sunlight. However, there are some defects in the application of TiO2 NPs as AF nanofillers in polymer coatings. From the antibacterial point of view, TiO2 NPs can only absorb UV light (λ < 400 nm, 5% of sunlight). Therefore, transferring the photocatalytic efficiency of TiO2 to the visible light direction (45% of sunlight) is a way to improve the antibacterial effect of TiO2 NPs, so as to improve the antipollution performance of PDMS coating loaded with TiO2 NPs.
3.2.5. Other metal and non-metal nanoparticles
With the gradual emergence of the advantages of inorganic nanofillers in polymer coatings, the incorporation of inorganic enhanced nanofillers has become inevitable. Enhancing the interaction between PDMS and nanofillers can save costs and improve mechanical, selfcleaning, super-hydrophobic and anti-fouling characteristics, especially by controlling the release of nanofillers to achieve stable anti-fouling characteristics under static conditions. This makes this nanostructured polymer coating potentially a very promising material for the future. In addition to the metal and its oxide nanoparticles mentioned above, some other metal oxides such as MnO2, ZrO2, Al2O3, Fe3O4 [89] and non-metal NPs such as SiO2 [90,91], SiC and other nano-fillers are often filled into the PDMS matrix to design composite coatings with micro-nano rough surfaces. According to literature reports, pure PDMS resin is often used as a matrix resin for anti-fouling coatings because of its non-toxic, stable and hydrophobic properties, but it has a significant disadvantage of poor mechanical properties [92], which can be significantly improved by inserting nano-fillers into the polymer matrix [22].
For PDMS AF coatings with different nanoparticles, Sohrabi's team has done a lot of research, in addition to the carbon nanomaterials mentioned earlier [93], there are also sunflower oil-based hyperbranched alkyd/spherical magnetite/silicone composites [89], oil-based hyperbranched alkyd/spherical ZnO nanocomposites [94], Ag@SiO2 core-shell nanocomposite [95], etc. Among them, Fe (II) and Fe (III) in the structure of nano-magnetite can bring superior biological and physico-chemical properties to the composite material, and the larger specific surface area of nano-iron particles can provide more active sites, which are widely used in biosensing, cell tracking and cancer therapy. The static WCA of the PDMS/magneto composite coating is 153°, and the surface energy SFE is 16.1 mN/m. After 3 months of testing in the real sea, the coating has a significant inhibitory effect on the growth of diatoms and bacteria [89], which mainly depends on the self-cleaning behavior of the coating to inhibit the development of microbial film entering the surface (Fig. 11). SiO2 has become an attractive nanomaterial for biological applications due to its excellent biocompatibility, high thermal stability and mechanical stability.
PDMS-based superhydrophobic antifouling coatings have been widely studied in recent years. The superhydrophobic surface can be constructed by introducing SiO2, PBA and other nanoparticles into the PDMS-based coating. Based on the previous self-healing coating of epoxy resin [96], Dong et al. [97] prepared a superhydrophobic coating with self-healing function by mixing PBA nanoparticles with PDMS. Ansari et al. [91] adopted a one-step method to prepare a superhydrophobic composite coating containing PDMS and SiO2 NPs (WCA: 161.6°, slip Angle SA: 4.1°) from the perspective of adjusting surface roughness to promote the formation of hydrophobic surface, with a roughness of 8.0–75.1 μm. This rough structure can help resist algal settlement by providing a stable gas-liquid interface, that is, when the roughness is smaller than the diameter of the algal robe, it will inhibit algal adhesion and achieve AF activity. In addition, the coating has a super-hydrophobic self-cleaning effect on water, cola, lemon juice and black tea (as a liquid), which could be used in the future to prepare marine AF and drag reduction coatings.
3.3. Amphiphilic polymer-PDMS AF coatings containing antibacterial nanomaterials
Zwitterionic polymers are polymer materials that contain a pair of positive and negative charges on the repeating unit through the hydration effect of ionic solvation. Their ionic bond strength and stability are much higher than that of traditional hydrophilic ionic polymers, and they have attracted much attention as an important substitute for traditional hydrophilic films (such as PEG). Zwitterionic polymers such as carboxylic acid betaine and sulfobetaine can make the charged groups on the zwitterionic repeating unit tightly bind water molecules to form a hydration layer due to their excellent hydrophilicity and hydration ability, resulting in significantly reduced adsorption capacity of proteins and other biomolecules, and become competitive AF materials [6].
Guymon et al. believe that although simple PDMS coating is non-toxic to biological cells, it is easy to adsorb proteins on the hydrophobic surface, and the introduction of zwitterions can improve this dilemma. Therefore, they prepared PDMS composite coatings containing zwitterionic polymers by using a one-step photoinitiated grafting process to covalently link poly(sulfobetaine methacrylate) (pSBMA) and poly(carboxybetaine methacrylate) (pCBMA) cross-linked hydrogel polymers to PDMS substrates [98]. Micrographs of protein fluorescence adsorption of composite materials found that the uncoated PDMS exhibited a bright green color whereas the pSBMA- and pCBMA-coated surfaces showed almost no fluorescence. Quantification of the adsorbed protein by measuring fluorescence intensity indicated a significant reduction in protein adsorption for both pSBMA- and pCBMA-coated surfaces compared to bare PDMS. Ghaleh et al. prepared a bionic anti-pollution PDMS surface by grafting hydrophilic poly(2-hydroxyethyl methacrylate) (PHEMA) brush on the UV/ozone-activated PDMS substratehydrophilic poly(2-hydroxyethyl methacrylate) (PHEMA) brush on the UV/ozone-activated PDMS substrate [99], their protein adsorption capacity decreased by 12.2% relative to pure PDMS, demonstrating that the introduction of zwitterionic polymers can prevent the adsorption of proteins.
Although zwitterionic polymer and PDMS copolymerized polymer materials by grafting can prevent protein adsorption, their service life and AF effect in marine environment are not ideal. Surface modification based on zwitterion has quickly become one of the effective methods of highly efficient anti-biofilm. The surface grafting or embedding of SiO2, Ag and other NPs in zwitterion polymers can effectively prevent the adhesion of proteins and fouling organisms. For example, Wang et al. first prepared functionalized nanosilica with amphiphilic block copolymers via surface-initiated atom transfer radical polymerization (SI-ATRP) with zwitterionic polymers N-vinylpyrrolidone (NVP) and trifluoromethyl methacrylate (TFEMA). Then, amphiphilic copolymers-functionalized silica, SiO2-g-(PVP-co-PTFEMA) are obtained and are incorporated into resin as an antifouling filler to obtain a nanocomposite coating [90]. The adhesion rate of the coating to bacteria and diatoms decreased by 74.4% and 69%, respectively. When the ionic liquid functionalized polystyrene nanospheres were introduced into the zwitterionic polymer, the adhesion of the composite coating to bacteria and diatoms was reduced by 83% and 85%, respectively [100]. In addition, anionic polymer brushes containing functionalized Ti3C2Tx showed good antibacterial and AF properties (removes more than 55% of bacteria and up to 71% of microalgae) [101]. Hu et al. embedded Ag NPs into the zwitterionic polymer obtained by in-situ polymerization of pSBMA and pCBMA, and formed new organic-inorganic nanocomposites [102], which could kill 99.8% of E. coli within 12 h and 98.7% of dead cells could be released from the surface, thus achieving the purpose of antibacterial and anti-adhesion (Fig. 12).
3.4. PDMS AF coatings containing natural antibacterial nanomaterials
Resins and AF agents are the most important components of marine AF coatings, which play a decisive role in the AF ability of materials. For soluble or swollen resin substrates, these AF agents kill or inhibit the growth of potentially fouling organisms by leaching them out and releasing them into seawater in a controlled manner, a strategy that has been well consolidated and used commercially. Although they are generally considered effective, such coatings usually require an effective mass transfer to ensure the efficiency of antibacterial agent, which is weak under static conditions and damages non-target creatures as well [103]. In contrast, for insoluble AF resin substrates such as PDMS coatings, AF agents added to them are not released into the ocean, they usually prevent fouling organisms from adhering to the coated surface by providing an inhospitable surface, and the organisms attached to the surface will soon die due to the action of the AF agent or antibacterial agents. Nanomaterials have become new antibacterial agents because of their high specific surface area. The insertion of nano-antibacterial fillers in PDMS can reduce roughness and surface free energy, and improve antibacterial properties, making nanomicides become one of the research hotspots of functional AF coatings. The addition of CNTs, organic modified montmorillonite, Ag, Cu/CuO/Cu2O and natural antibacterial agents such as eugenol, capsaicin and natural foam to PDMS coatings can significantly improve their antibacterial and AF properties.
Insertion of natural sepiolite Si12O30Mg8(OH)4(H2O)4⋅8H2O NPs in commercial vinyl terminated PDMS reduces the modulus of elasticity and the relative adhesion of fouling communities. The high surface area of sepiolite is attributed to its micropores, channels, fine particle size (5–10 nm in diameter), and fibrous nature [44]. Yu et al. synthesized a variety of different derived antibacterial agents by analyzing the structure of natural capsaicin such as indole and capsaicin, all of which showed good antibacterial activity [104,105]. In order to improve the antifouling activity of natural capsaicin-derived antibacterial agents, Zhang et al. prepared capsaicin-derived self-polymer NPs, which had significantly higher antibacterial performance than capsaicin-derived antibacterial agents [106]. Borneol has been used as an antibacterial material in traditional Chinese medicine due to its unique chiral structure and excellent anti-bacterial adhesion properties. Zhao et al. prepared the environment-friendly silicone AF coatings by introducing the isobornyl as AF groups and dodecfluoroheptyl into the silicone side chains [107], which exhibited high adhesion (>2 MPa, steel plates), excellent antibacterial ability (antibacterial rate against marine bacteria Pseudomonas sp. reached 95.6%) and outstanding anti-fouling ability (biofilm coverage reduced by 86.9%, effective anti-fouling period more than 6 months) (Fig. 13a). Lin et al. prepared Bioinspired self-stratification fouling release silicone coating [108] using natural phenolic derivatives (eugenol and catechol) and poly (dimethylsiloxane) etherimide are used as raw materials (Fig. 13b), their largest underwater adhesive strength of this coating reaches 3.0 - 0.1 MPa, the lowest storage moduli was 0.1 MPa, the WCA was greater than 90°, and the area coverage of bacteria and diatoms were lower than 1% and 4% after co-culture on the coated surface for 24h, showing excellent mechanical, hydrophobic and AF properties.
In addition to the direct addition or co-polymerization of the above naturally derived antimicrobials with nanostructures in the resin matrix, the use of other NPs such as chitosan NPs, biosynthesized iron, Ag and other NPs loaded or surface polymerized naturally derived antimicrobials is also a very important method to prepare natural antimicrobials containing PDMS AF coatings [109]. In the future, the synthesis methods of natural antimicrobial nanomaterials and the preparation process of PDMS composites will be more diversified, but in any case, the future research on PDMS coatings containing natural antimicrobial agents will be developed in the direction of more economical, effective and environmentally friendly.
3.5. Hydrogel-PDMS AF coatings containing antibacterial nanomaterial
Hydrogels are composed of hydrophilic polymer network structures, in these porous three-dimensional network structures 80% of the composition of water, due to their non-toxic, high elastic and adhesion to biological proteins make them suitable for the prevention of marine biological fouling and pharmaceutical fields [110,111]. The hydrogel coating prepared by PDMS crosslinked N-isopropylacrylamide (NIPAM), N,N0 -methylenebis (2-propenamide) (NNMBA), and synthetic antibacterial peptide (AMP) can achieve a low bacterial adhesion rate (as low as 3.4%) at room temperature, and the bactericidal capacity can reach almost 100% [112], and the adsorption capacity of anti-protein on the surface of Silicone hydrogels based on amphiphilic poly(2-methyl-2-oxazoline)-b-poly(dimethyl siloxane) copolymer is about 3.76 μg/m°2 [113]. All the above studies prove that hydrogels, especially PDMS based hydrogels, are the potential AF material
At present, great progress has been made in the study of hydrogels, but there is still no practical application of hydrogels on the surface of marine hulls. The possible reasons include poor mechanical properties of hydrogels and fragile dehydration. As a common reinforcement in polymer materials, nanomaterials have significant effects in improving the mechanical strength and anti-fouling ability of materials. For example, poly(carboxybetaine methacrylamide-co-HEMA) nanocomposite hydrogels have excellent mechanical properties, with a maximum tensile ratio of up to 1800% [114]. Li et al. prepared a double-layer hydrogel/nanofiber film composite using methacryloyl chitosan (MC), oxidized chitosan (OC), polyurethane (PU) and PDMS as raw materials. The maximum elongation at break can reach 136.4 kPa, the hydrogel composites were recoverable after being compressed to 40%, 60% and 80% strain, the 50 cyclic loading-unloading compression tests with a large strain of 60% showed a good compressive resilience [115].
The mechanical strength of nanocomposites in hydrogels has been improved, and the antibacterial and antifouling ability of PDMS hydrogel nanocomposites has also been widely addressed. Liu et al. [116] found that the AgNPs-PDMS-hydrogel interpenetrating polymer network hydrogels constructed in the AgNPs and PDMS matrix (Fig. 14), are gradually covered by a thin silicon film, due to the presence of spherical aggregates, and showed that they could firmly be embedded in the coating. The composite coating prepared by this method can kill nearly 100% of E.coli and reduce algal deposition by 52%. The AF property of composite coatings is significantly improved. This approach also solved successfully the problem of poor compatibility between AgNPs and PDMS matrix. Based on the principle of surface hydrophilicity, AgNPs were surface functionalized by pure polyacrylic acid (PAA) and polyimine (PEI) by Rahaman et al. [117], and then hydrophilic polysulfobetaine or low surface energy polydimethylsiloxane (PDMS) were grafted with polymer brush to prepare hydrophilic AF coatings. LBL membrane and sulfobetaine polymer brush can significantly improve the hydrophilicity of the membrane surface. The contact angle is reduced to 70° and the surface energy is 35 mJ/m2 . In the microbial adhesion test of E.coli, the standardized cell adhesion range on the modified membrane surface was only 4–16%. The bacteria inactivation rate of LBL membrane coated with PAA/Ag-PEI reached 95% within 1 hour of contact time.
3.6. Multiple PDMS nanocomposite coatings
To effectively improve the mechanical properties and AF ability of PDMS nano reinforced composites, a variety of inorganic materials and core-shell nanostructures were introduced on the basis of a single NPsPDMS composite. The researchers hope to give PDMS resin unique chemical and physical properties through the combination of various nanoparticles, and improve the anti-fouling ability and dirt release ability of the coating [118]. ZnO and TiO2 NPs are most commonly used, while Cu2O, CuO, Al2O3 and SiO2 are also incorporated into nanocomposite coatings.
Recently, researchers have investigated the combined properties of ZnO NPs and GO and reported the effects of incorporation of these materials into the base polymer matrix as nano enhancers [119]. Although ZnO NPs show excellent performance in enhancing AF and mechanical properties, when the concentration exceeds a certain level, due to their nanometer size, ZnO NPs will form aggregates in the original polymer solution, which will affect their uniform distribution in the formation process of the matrix [120]. Among various metal oxide NPs, ZnO NPs showed higher levels of toxicity than CuO NPs. Globally, ZnO NPs have been used to protect coatings from both Gram-negative and Gram-positive bacteria such as E. coli and Bacillus subtilis [70]. As ZnO NPs tend to alter the microenvironment close to bacteria/other microorganisms and increase solubility, they eventually cause damage to bacterial cells. The bacterial cell damage mechanism caused by Zn/Ag NPs incorporation [121] is shown in Fig. 15.
Based on this, Zinc-GO nanocomposites were prepared by Zhang et al. [122] by one-pot method, and PDMS/ZnO-GO nanocomposites (PZGO) were prepared by solution mixing by adding different amounts of ZnO-GO into the PDMS matrix. The results showed that the increase in the content of ZnO-GO nanofiller decreased the surface energy (SFE) from 20.02 mN/m of the original PDMS to 9.06 mN/m (PZGO 0.2 wt%), the amount of ZnO nanofiller in PDMS increased, and the WCA increased to 117°. Synechococcus sp. Strain PCC 7002 and Phaeodactylum tricornutum were used for 7 days AF test. PZGO0.2 (ZnO-GO/PDMS mass ratio: 0.2 wt%) showed 8.5% biofilms coverage, while PZGO0.1 (ZnOGO/PDMS mass ratio: 0.1 wt%) was 2.4%. It is of great significance to use non-toxic materials and environment-friendly solvents to prepare environment-friendly materials in order to reduce environmental pollution. GO was reduced by plant extracts, AgNO3 was added to GO suspension, and NPs were dispersed in PDMS. GOH@Ag nanocomposites were proposed by Soolmaz et al. [123]. The Composite samples synthesized by GOH@Ag nanofillers has the lowest critical surface energy (16 mN/m). The lowest adhesion strength of 0.5% pseudobarnacle was 0.016 MPa. Samples soaked in seawater for 4 days had the lowest bacterial density (OD600 1/4 0.079 - 0.0029). Static immersion tests were conducted in seawater for more than 60 days. Compared with the blank coating, GOH@Ag nanocomposite coating has almost no fouling biological adhesion on the surface (Fig. 16). Calculate the efficiency of N values for all samples at 15 days intervals, with a minimum N value of 18.
In addition to hydrothermal method, sol-gel method and dip coating method, there are some limitations in the careful design of micro nanostructure. Cu-metal organic frameworks (MOF) nanowhiskers were in situ synthesized on Cu(OH)2@Cu mesh. Then MOF@Cu was first proposed by Wang et al. [124] The mushrooms like structure of PDMS@MOF@Cu mesh composed of the layered structure of nanowires and nanowires prepared by the dip coating process is shown in Fig. 17a. The static contact angle and sliding angle were 151.8° and 3.6° respectively. In order to investigate the actual decontamination ability of the material, the ability to remove pollutants from various solutions (dyeing water, tea, milk, fruit juice, coffee, coke) was verified by experiments. The experimental results showed that a number of drops on the surface of PDMS@MOF@Cu mesh were in the shape of a ball, with higher super water repellency and fouling resistance. The contact angles decreased to 142° and 134°. Respectively, after soaking in acid and alkaline solutions for 24 h. The peeling test of 3 M tape under certain pressure proved that it has excellent adhesive strength, and the super drainage copper mesh has great potential in ship drag reduction. The AlO3-PDMS-Cu coating, prepared by penetrating PDMS into the plasma sprayed porous AlO3-Cu coating, exhibits excellent wear resistance, mechanical strength and anti-fouling, and its inhibition rate against E. coli can reach 94% [125].
Based on the core-shell structure, which combines the two-phase properties with different chemical compositions and crystal structures, it may increase the colloidal stability. Nano silica shell is suitable for biological coupling due to its surface characteristics, but there is no data on the preparation of silicone/Ag@SiO2 core-shell composites for marine AF coatings. Core-shell nanospheres Ag@SiO2 with controllable shell thickness, average size of 60 nm and preferred growth direction of [110] were prepared by Selim et al. [95] by solvothermal method and improved Stober method. Three nano-fillers with different concentrations were mixed with PDMS to realize the superhydrophobic surface. The AF mechanism is shown in Fig. 17b. Static contact angle test shows that the original PDMS coating is 107°, but the coating increases to 156° and the surface energy decreases to 11.15 mN/m after adding 0.5% Ag@SiO2. The mechanical property experiment shows that the tensile modulus increases with the increase of the addition amount, up to 6.8 MPa, but the tensile modulus of the coating with 0.5% addition amount is 3.6 - 0.5 MPa. The PDMS/Ag@SiO2 core-shell (0.5 wt%) composite showed no cracks in the impact strength test up to 14 J, indicating that the good dispersion of NPs can enhance the flexibility and mechanical strength of the coating. The 28 days static AF test showed that the fouling adhesion on the surface of 0.5% PDMS/Ag@SiO2 coating was the lowest. Mohamed S. Selim synthesized a novel, low-cost PDMS/controlled SiO2-doped ZnO nanocomposites using hydrogenated siloxane curing technology. The CA increased to 167° - 2°, while the Ra values drastically decreased to 0.11 - 0.01 μm with 0.5% nanofiller samples [126].
In addition to using inorganic metal nanomaterials as AF groups, based on natural antibacterial products (capsaicin, indoles, alkaloids, etc.) bactericidal effect. Lu et al. [127] prepared a composite nanomaterial (FeCap) combining the natural antibacterial agent capsaicin with CoFe2O4/gelatin magnetic nanoparticles, and then mixed FeCap with PDMS-based block copolymer to construct a directional non-permeable capsaicin nanocomposite coating. In order to control the elastic modulus of PSDV/FeCap, a layer of polystyrene block polystyrene (ethylene-butene) - block polystyrene (SEBS) was introduced below it. The results show that the elastic modulus of the composite is 5.0 MPa, the removal rate of N.subminuscula is 36.2%, and its settlement density is lower than 3 cells/0.188 mm2 (Fig. 18).
The fouling release method based on the synergistic interaction of multiple NPs and amphiphilic polymer modified NPs provides a new idea to solve the fouling adhesion problem in the field of marine AF and has great application potential.
4. Conclusion and outlook
This article discusses in detail the unique properties of various nanomaterials enhanced PDMS matrix and their applications in marine AF field, including carbon NPs, metal NPs (Ag, ZnO, TiO2, Cu2O, CuO), amphiphilic polymer natural antibacterial agent, photocatalytic material, hydrogel material and multiple composite NPs. Compared with pure PDMS, nanocomposite the incorporation of these nanomaterials could enhance the mechanical properties and AF ability to some extent. However, taking the practical application requirements of PDMS coatings into consideration, such as the high mechanical properties and excellent AF ability at static seawater atmosphere, there are still many challenges in this field. Currently, it is common knowledge that the best way to achieve long-term AF for both static and dynamic situation is to develop multifunctional AF coatings with synergistic advantages. Nevertheless, before the practical applications, there are still many fundamental and technical questions, such as but not limited to: (1) The material aspect, by introducing nanomaterials of different types, sizes, concentrations, with different surface functional group and morphology would definitely influence the properties of PDMS coatings, therefore, more exploration on the material structure and dose should be further investigated, as well as the interaction between nanomaterial and PDMS matrix. By doing so, it will provide deeper insight into the mechanism of how nanomaterials enhance the PDMS mechanical properties; (2) Improvement of AF properties, more AF strategies should orchestrated based on different nanomaterials, such as the combination of new materials with different (orthogonal) properties, like self-cleaning, ROS generation, photocatalytic or even germicide releasing properties; (3) Marine biological fouling formation stages, more investigation on the relationship between the early formation mechanism of biofouling and nanomaterialenhanced PDMS coatings should be explored. This would allow to implement the AF at the early stage; (4), Large-scale production of nanomaterials-enhanced PDMS coatings, key factors regarding this large scale production should be considered, such as synthetic routes, final cost, etc.
Declaration of competing interest
The authors declare that they have no conflict of interest.
Acknowledgments
This work was financially supported by National Natural Science Foundation of China (Grant No. 52073071, 51803041), Natural Science Funding for Excellent Young Scholar of Heilongjiang Province (YQ2022E021, L. Wang), the Fundamental Research Funds for the Central Universities (HIT.DZJJ.2023056), and the Research Fund of State Key Laboratory for Marine Corrosion and Protection of Luoyang Ship Material Research Institute (No. JS220407). P.E.D.S.R acknowledges the financial support from the Spanish Ministry of Economy and the Canary Islands program Viera y Clavijo Senior (Ref. 2023/00001156).
ARTICLE INFO
Received 9 October 2023; Accepted 7 December 2023
Available online 10 January 2024
* Corresponding author. School of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, China.
** Corresponding author.
*** Corresponding author.
**** Corresponding author. School of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, China.
E-mail addresses: [email protected] (W. Zhou), [email protected] (C. Lin), [email protected] (L. Wang), [email protected] (Z. Zhang).
References
[1] H. Qiu, K. Feng, A. Gapeeva, K. Meurisch, S. Kaps, X. Li, L. Yu, Y.K. Mishra, R. Adelung, M. Baum, Functional polymer materials for modern marine biofouling control, Prog. Polym. Sci. 127 (2022) 101516.
[2] S. Song, Y.K. Demirel, M. Atlar, An investigation into the effect of biofouling on the ship hydrodynamic characteristics using CFD, Ocean Eng. 175 (2019) 122–137.
[3] K.A. Dafforn,j.A. Lewis, E.L. Johnston, Antifouling strategies: history and regulation, ecological impacts and mitigation, Mar. Pollut. Bull. 62 (3) (2011) 453–465.
[4] M.P. Schultz,j.A. Bendick, E.R. Holm, W.M. Hertel, Economic impact of biofouling on a naval surface ship, Biofouling 27 (1) (2011) 87–98.
[5] M.P. Schultz, Effects of coating roughness and biofouling on ship resistance and powering, Biofouling 23 (5–6) (2007) 331–341.
[6] M.S. Selim, M.A. Shenashen, S.A. El-Safty, S.A. Higazy, M.M. Selim, H. Isago, A. Elmarakbi, Recent progress in marine foul-release polymeric nanocomposite coatings, Prog. Mater. Sci. 87 (2017) 1–32.
[7]j. Bannister, M. Sievers, F. Bush, N. Bloecher, Biofouling in marine aquaculture: a review of recent research and developments, Biofouling 35 (6) (2019) 631–648.
[8] E. Lacoste, N. Gaertner-Mazouni, Biofouling impact on production and ecosystem functioning: a review for bivalve aquaculture, Rev. Aquacult. 7 (3) (2015) 187–196.
[9] M. Otani, T. Oumi, S. Uwai, T. Hanyuda, R.E. Prabowo, T. Yamaguchi, H. Kawai, Occurrence and diversity of barnacles on international ships visiting Osaka Bay, Japan, and the risk of their introduction, Biofouling 23 (3–4) (2007) 277–286.
[10] I. Fitridge, T. Dempster,j. Guenther, R. de Nys, The impact and control of biofouling in marine aquaculture: a review, Biofouling 28 (7) (2012) 649–669.
[11] K.V. Thomas, S. Brooks, The environmental fate and effects of antifouling paint biocides, Biofouling 26 (1) (2010) 73–88.
[12] I. Amara, W. Miled, R.B. Slama, N. Ladhari, Antifouling processes and toxicity effects of antifouling paints on marine environment, A review. Environmental Toxicology and Pharmacology 57 (2018) 115–130.
[13] I.K. Konstantinou, T.A. Albanis, Worldwide occurrence and effects of antifouling paint booster biocides in the aquatic environment: a review, Environ. Int. 30 (2) (2004) 235–248.
[14] H. Wang, X. Liu, D.E. Christiansen, S. Fattahpour, K. Wang, H. Song, S. Mehraeen, G. Cheng, Thermoplastic polyurethane with controllable degradation and critical anti-fouling properties, Biomater. Sci. 9 (4) (2021) 1381–1396.
[15] M. Yu, M. Liu, S. Fu, Slippery antifouling polysiloxane-polyurea surfaces with matrix self-healing and lubricant self-replenishing, ACS Appl. Mater. Interfaces 13 (27) (2021) 32149–32160.
[16] G. Mirchandani, S. Samanta, V.B. Raghavendra, S. Chaudhary, S. Baustkar, S. Shyamroy, N.K. Singha, Self-stratifying amphiphobic coating based on functional polyacrylates, Prog. Org. Coating 152 (2021) 106106.
[17] Z. Wang, H. Zuilhof, Antifouling properties of fluoropolymer brushes toward organic polymers: the influence of composition, thickness, brush architecture, and annealing, Langmuir 32 (26) (2016) 6571–6581.
[18] H. Hu, M. Chen, M. Cao, TiO2 antifouling coating based on epoxy-modified tung oil waterborne resin, Polym. Polym. Compos. 29 (2021) S521–S529.
[19] D. Hu, Y. Li, Z. Yan, S. Li, M. Xu, C. Wang, Anti-fouling nanofiltration membranes based on macromolecule crosslinked polyvinyl alcohol,j. Ind. Eng. Chem. 112 (2022) 348–357.
[20] G. Wu, C. Li, X. Jiang, L. Yu, Highly efficient antifouling property based on selfgenerating hydrogel layer of polyacrylamide coatings,j. Appl. Polym. Sci. 133 (42) (2016).
[21] H. Zhang, M. Chiao, Anti-fouling coatings of poly(dimethylsiloxane) devices for biological and biomedical applications,j. Med. Biol. Eng. 35 (2) (2015) 143–155.
[22] M.S. Selim, S.A. El-Safty, M.A. Shenashen, S.A. Higazy, A. Elmarakbi, Progress in biomimetic leverages for marine antifouling using nanocomposite coatings,j. Mater. Chem. B 8 (17) (2020) 3701–3732.
[23] P. Hu, Q. Xie, C. Ma, G. Zhang, Silicone-based fouling-release coatings for marine antifouling, Langmuir 36 (9) (2020) 2170–2183.
[24] W. Wang,j. Li, P. Wang,j. Ou, D. Zhang, Fabrication of polydimethylsiloxaneattached solid slippery surface with high underwater transparency towards the antifouling of optical window for marine instruments,j. Colloid Interface Sci. 623 (2022) 832–844.
[25] V. Uskokovi°c, L.E. Bertassoni, Nanotechnology in dental sciences: moving towards a finer way of doing dentistry, Materials 3 (3) (2010) 1674–1691.
[26] S.H. Chung, A. Manthiram, Current status and future prospects of metal-sulfur batteries, Adv. Mater. 31 (27) (2019) 1901125.
[27] C. Zhu, G. Yang, H. Li, D. Du, Y. Lin, Electrochemical sensors and biosensors based on nanomaterials and nanostructures, Anal. Chem. 87 (1) (2015) 230–249.
[28] S. Baruah, M. Jaisai,j. Dutta, Development of a visible light active photocatalytic portable water purification unit using ZnO nanorods, Catal. Sci. Technol. 2 (5) (2012) 918–921.
[29] S. Kumar, F. Ye, S. Dobretsov,j. Dutta, Nanocoating is a new way for biofouling prevention, Frontiers in Nanotechnology 3 (2021).
[30] D.M. Yebra, S. Kiil, K. Dam-Johansen, Antifouling technology-past, present and future steps towards efficient and environmentally friendly antifouling coatings, Prog. Org. Coating 50 (2) (2004) 75–104.
[31] L. Delauney, C. Comp-ere, M. Lehaitre, Biofouling protection for marine environmental sensors, Ocean Sci. 6 (2) (2010) 503–511.
[32] A. Jain, N.B. Bhosle, Biochemical composition of the marine conditioning film: implications for bacterial adhesion, Biofouling 25 (1) (2009) 13–19.
[33]j. Shimeta,j. Cutajar, M.G. Watson, T. Vlamis, Influences of biofilm-associated ciliates on the settlement of marine invertebrate larvae, Mar. Ecol. Prog. Ser. 449 (2012) 1–12.
[34] H.H. Tuson, D.B. Weibel, Bacteria-surface interactions, Soft Matter 9 (18) (2013) 4368–4380.
[35] A.G. Nurioglu, A. Esteves, G. de With, Non-toxic, non-biocide-release antifouling coatings based on molecular structure design for marine applications,j. Mater. Chem. B 3 (32) (2015) 6547–6570.
[36] S. Sharmeen, A.F.M.M. Rahman, M.M. Lubna, K.S. Salem, R. Islam, M.A. Khan, Polyethylene glycol functionalized carbon nanotubes/gelatin-chitosan nanocomposite: an approach for significant drug release, Bioact. Mater. 3 (3) (2018) 236–244.
[37]j. Xu, K. Yao, Z. Xu, Nanomaterials with a photothermal effect for antibacterial activities: an overview, Nanoscale 11 (18) (2019) 868–8691.
[38] D.A. Walters, L.M. Ericson, M.J. Casavant,j. Liu, D.T. Colbert, K.A. Smith, R.E. Smalley, Elastic strain of freely suspended single-wall carbon nanotube ropes, Appl. Phys. Lett. 74 (25) (1999) 3803–3805.
[39] T. Mocan, C.T. Matea, T. Pop, O. Mosteanu, A.D. Buzoianu, S. Suciu, C. Puia, C. Zdrehus, C. Iancu, L. Mocan, Carbon nanotubes as anti-bacterial agents, Cell. Mol. Life Sci. 74 (19) (2017) 3467–3479.
[40] Y. Zhu,j. Xu, Y. Wang, C. Chen, H. Gu, Y. Chai, Y. Wang, Silver nanoparticlesdecorated and mesoporous silica coated single-walled carbon nanotubes with an enhanced antibacterial activity for killing drug-resistant bacteria, Nano Res. 13 (2) (2020) 389–400.
[41] S. Wang, X. Liu, L. Yu, Y. Zhao, M. Sun, Low surface energy self-polishing polymer graftedMWNTs for antibacterial coating and controlled-release property of Cu2O,j. Appl. Polym. Sci. 138 (16) (2021) 50267.
[42] A. Dasgupta, L.P. Rajukumar, C. Rotella, Y. Lei, M. Terrones, Covalent threedimensional networks of graphene and carbon nanotubes: synthesis and environmental applications, Nano Today 12 (2017) 116–135.
[43] Y. Sun, Y. Ji, Y. Lang, L. Wang, B. Liu, Z. Zhang, A Comparative Study on the Impact of the Carbon Nanotubes-Modified Polydimethylsiloxane Nanocomposites on the Colonization Dynamics of the Pioneer Biofilm Communities, International Biodeterioration & Biodegradation, 2018.
[44] M. Wouters, C. Rentrop, P. Willemsen, Surface structuring and coating performance: novel biocidefree nanocomposite coatings with anti-fouling and fouling-release properties, Prog. Org. Coating 68 (1) (2010) 4–11.
[45] F. Irani, A. Jannesari, S. Bastani, Effect of fluorination of multiwalled carbon nanotubes (MWCNTs) on the surface properties of fouling-release silicone/ MWCNTs coatings, Prog. Org. Coating 76 (2–3) (2013) 375–383.
[46] Y. Ji, Y. Sun, Y. Lang, L. Wang, B. Liu, Z. Zhang, Effect of CNT/PDMS nanocomposites on the dynamics of pioneer bacterial communities in the natural biofilms of seawater, Materials 11 (6) (2018) 902.
[47] Y. Lang, Y. Sun, M. Yu, Y. Ji, L. Wang, Z. Zhang, Differential colonization dynamics of marine biofilm-forming eukaryotic microbes on different protective coating materials, Polymers 11 (1) (2019) 161.
[48] Y. Sun, Y. Lang, Z. Yan, L. Wang, Z. Zhang, High-throughput sequencing analysis of marine pioneer surface-biofilm bacteria communities on different PDMS-based coatings, Colloids Surf. B Biointerfaces 185 (2020) 110538.
[49] P. Kumar, P. Huo, R. Zhang, B. Liu, Antibacterial properties of graphene-based nanomaterials, Nanomaterials 9 (5) (2019) 737.
[50] F. Sousa-Cardoso, R. Teixeira-Santos, A.F. Campos, M. Lima, L.C. Gomes, O.S.G.P. Soares, F.J. Mergulh~ao, Graphene-based coating to mitigate biofilm development in marine environments, Nanomaterials 13 (3) (2023) 381.
[51] H. Jin, L. Tian, W. Bing,j. Zhao, L. Ren, Toward the application of graphene for combating marine biofouling, Advanced Sustainable Systems 5 (1) (2021) 2000076.
[52] T. Mesari•c, K. Sep•ci•c, V. Piazza, C. Gambardella, F. Garaventa, D. Drobne, M. Faimali, Effects of nano carbon black and single-layer graphene oxide on settlement, survival and swimming behaviour of Amphibalanus amphitrite larvae, Chem. Ecol. 29 (7) (2013) 643–652.
[53] L. Cavas, P.G. Yildiz, P. Mimigianni, A. Sapalidis, S. Nitodas, Reinforcement effects of multiwall carbon nanotubes and graphene oxide on PDMS marine coatings,j. Coating Technol. Res. 15 (1) (2018) 105–120.
[54] X. Hu, W. Qian, X. Li, G. Fei, G. Luo, Z. Wang, H. Xia, A novel method to prepare homogeneous biocompatible graphene-based PDMS composites with enhanced mechanical, thermal and antibacterial properties, Polym. Compos. 40 (S2) (2018) E1397–E1406.
[55] M. Ramezanzadeh, B. Ramezanzadeh, G. Bahlakeh, A. Tati, M. Mahdavian, Development of an active/barrier bi-functional anti-corrosion system based on the epoxy nanocomposite loaded with highly-coordinated functionalized zirconiumbased nanoporous metal-organic framework (Zr-MOF), Chem. Eng.j. 408 (2021) 127361.
[56] M. Ramezanzadeh, B. Ramezanzadeh, M. Mahdavian, G. Bahlakeh, Development of metal-organic framework (MOF) decorated graphene oxide nanoplatforms for anti-corrosion epoxy coatings, Carbon 161 (2020) 231–251.
[57] Z. Zhou, A. Seif, S. Pourhashem,j. Duan, A. Rashidi, P. Luigi Silvestrelli, X. Ji, M. Mirzaee, B. Hou, Multi-treatments based on polydimethylsiloxane and metalorganic framework wrapped with graphene oxide for achieving long-term corrosion and fouling protection: experimental and density functional theory aspects, Construct. Build. Mater. 384 (2023) 131229.
[58] M.S. Selim, N.A. Fatthallah, S.A. Higazy, Z. Hao, P. Jing Mo, A comparative study between two novel silicone/graphene-based nanostructured surfaces for maritime antifouling,j. Colloid Interface Sci. 606 (2022) 367–383.
[59] S. Barthwal, S. Barthwal, B. Singh, N. Bahadur Singh, Multifunctional and fluorine-free superhydrophobic composite coating based on PDMS modified MWCNTs/ZnO with self-cleaning, oil-water separation, and flame retardant properties, Colloids Surf. A Physicochem. Eng. Asp. 597 (2020) 124776.
[60] Q. Chen, Z. Zhang, Y. Qi, Influence of different silicone oils on properties of MWCNTs-OH/PDMS coatings, Surf. Eng. 38 (2) (2022) 191–198.
[61] S. Soleimani, A. Jannesari, M. Yousefzadi, A. Ghaderi, A. Shahdadi, Eco-friendly foul release coatings based on a novel reduced graphene oxide/Ag nanocomposite prepared by a green synthesis approach, Prog. Org. Coating: An International Review Journal (151) (2021) 151.
[62] M.S. Selim, N.A. Fatthallah, M.A. Shenashen, S.A. Higazy, H.R. Madian, M.M. Selim, S.A. El-Safty, Bioinspired graphene oxide-magnetite nanocomposite coatings as protective superhydrophobic antifouling surfaces, Langmuir 39 (6) (2023) 2333–2346.
[63] D.M. Yebra, S. Kiil, C.E. Weinell, K. Dam-Johansen, Effects of marine microbial biofilms on the biocide release rate from antifouling paints-A model-based analysis, Prog. Org. Coating 57 (1) (2006) 56–66.
[64] S.R. Lakhotia, M. M, K. P, Surface-Modified Nanocomposite Membranes, Separation & Purification Reviews, 2018.
[65] M.M. Khan, S.F. Adil, A. Al-Mayouf, Metal oxides as photocatalysts,j. Saudi Chem. Soc. 19 (5) (2015) 462–464.
[66] G. Carr°e, E. Hamon, S. Ennahar, M. Estner, M. Lett, P. Horvatovich,j. Gies, V. Keller, N. Keller, P. Andre, TiO2 photocatalysis damages lipids and proteins in Escherichia coli, Appl. Environ. Microbiol. 80 (8) (2014) 2573–2581.
[67] M. Al-Fori, S. Dobretsov, M.T.Z. Myint,j. Dutta, Antifouling properties of zinc oxide nanorod coatings, Biofouling 30 (7) (2014) 871–882.
[68] Z. Mao, W. Hao, W. Wang, F. Ma, C. Ma, S. Chen, BiOI@CeO2@Ti3C2 MXene composite S-scheme photocatalyst with excellent bacteriostatic properties,j. Colloid Interface Sci. 633 (2023) 836–850.
[69] G. Xiong, Z. Zhang, C. Zhang, Y. Qi, SLAP@g-C3N4 fluorescent photocatalytic composite powders enhance the anti-bacteria adhesion performance and mechanism of polydimethylsiloxane coatings, Nanomaterials 12 (17) (2022) 3005.
[70] L.S. Devi, S.R. Joshi, Antimicrobial and synergistic effects of silver nanoparticles synthesized using soil fungi of high altitudes of eastern himalaya, MYCOBIOLOGY 40 (1) (2012) 27–34.
[71]j.S. Kim, E. Kuk, K.N. Yu,j. Kim, S.J. Park, H.J. Lee, S.H. Kim, Y.K. Park, Y.H. Park, C. Hwang, Y. Kim, Y. Lee, D.H. Jeong, M. Cho, Antimicrobial effects of silver nanoparticles, Nanomed. Nanotechnol. Biol. Med. 3 (1) (2007) 95–101.
[72] V. Pareek, R. Gupta,j. Panwar, Do physico-chemical properties of silver nanoparticles decide their interaction with biological media and bactericidal action? A review, Mater. Sci. Eng. C 90 (2018) 739–749.
[73] M.S. Selim, S.A. El-Safty, M.A. El-Sockary, A.I. Hashem, O.M. Abo Elenien, A.M. EL-Saeed, N.A. Fatthallah, Modeling of spherical silver nanoparticles in silicone-based nanocomposites for marine antifouling, RSC Adv. 5 (78) (2015) 63175–63185.
[74]j. Chapman, L. Le Nor, R. Brown, E. Kitteringham, S. Russell, T. Sullivan, F. Regan, Antifouling performances of macro- to micro- to nano-copper materials for the inhibition of biofouling in its early stages,j. Mater. Chem. B 1 (45) (2013) 6194–6200.
[75] S. Jiang, T. Sreethawong, S.S.C. Lee, M.B.J. Low, K.Y. Win, A.M. Brzozowska, S.L. Teo, G.J. Vancso, D. Janczewski, M. Han, Fabrication of copper nanowire ° films and their incorporation into polymer matrices for antibacterial and marine antifouling applications, Adv. Mater. Interfac. 2 (3) (2015) 1400483.
[76] M.S. Selim, S.A. El-Safty, M.A. El-Sockary, A.I. Hashem, O.M. Abo Elenien, A.M. EL-Saeed, N.A. Fatthallah, Tailored design of Cu2O nanocube/silicone composites as efficient foul-release coatings, RSC Adv. 5 (26) (2015) 19933–19943.
[77] A.R. Padmavathi, P.S. Murthy, A. Das, P. Veeramani, T.S. Rao, Inorganic nanoparticle embedded Polydimethyl siloxane nanocomposites for biofouling mitigation, Surface. Interfac. 25 (2021) 101171.
[78] A. Ramanujam Padmavathi, P. Sriyutha Murthy, A. Das, T. Subba Rao, Enhanced antifouling property of polydimethylsiloxane-CuO nanocomposite in marine environment, Mater. Lett. 301 (2021) 130342.
[79] L. Wallenhorst, L. Gur°au, A. Gellerich, H. Militz, G. Ohms, W. Viol, UV-blocking € properties of Zn/ZnO coatings on wood deposited by cold plasma spraying at atmospheric pressure, Appl. Surf. Sci. 434 (2018) 1183–1192.
[80] X. Li,j. Yan, T. Yu, B. Zhang, Versatile nonfluorinated superhydrophobic coating with self-cleaning, anti-fouling, anti-corrosion and mechanical stability, Colloids Surf. A Physicochem. Eng. Asp. 642 (2022) 128701.
[81] Y. Bao, P. Tang, X. Shi, L. Gao, Durable superhydrophobic coatings based on flower-like zinc oxide via layer by layer spraying,j. Adhes. 98 (12) (2022) 1801–1819.
[82] M.S. Selim, H. Yang, F.Q. Wang, N.A. Fatthallah, Y. Huang, S. Kuga, Silicone/ZnO nanorod composite coating as a marine antifouling surface, Appl. Surf. Sci. 466 (2019) 40–50.
[83] S. Verma, S. Das, S. Mohanty, S.K. Nayak, Development of multifunctional polydimethylsiloxane (PDMS)-epoxy-zinc oxide nanocomposite coatings for marine applications, Polym. Adv. Technol. 30 (9) (2019) 2275–2300.
[84] I.O. Arukalam, E.E. Oguzie, Y. Li, Fabrication of FDTS-modified PDMS-ZnO nanocomposite hydrophobic coating with anti-fouling capability for corrosion protection of Q235 steel,j. Colloid Interface Sci. 484 (2016) 220–228.
[85] F. Xu, T. Wang, H. Chen,j. Bohling, A.M. Maurice, L. Wu, S. Zhou, Preparation of photocatalytic TiO2 -based self-cleaning coatings for painted surface without interlayer, Prog. Org. Coating 113 (2017) 15–24.
[86] T. Adachi, S.S. Latthe, S.W. Gosavi, N. Roy, N. Suzuki, H. Ikari, K. Kato, K. Katsumata, K. Nakata, M. Furudate, T. Inoue, T. Kondo, M. Yuasa, A. Fujishima, C. Terashima, Photocatalytic, superhydrophilic, self-cleaning TiO2 coating on cheap, light-weight, flexible polycarbonate substrates, Appl. Surf. Sci. 458 (2018) 917–923.
[87] X. Ding, R. Liu,j. Zhao,j. Hu, H. Guan, Y. Tong, Photocatalytic TiO2/PDMS coating to drive self-cleaning: a facile approach for anti-stain silicone rubber surfaces, Polym. Bull. 79 (8) (2022) 6431–6444.
[88] M.S. Selim, S.A. El-Safty, M.A. El-Sockary, A.I. Hashem, O.M.A. Elenien, A.M. ELSaeed, N.A. Fatthallah, Smart photo-induced silicone/TiO2 nanocomposites with dominant [110] exposed surfaces for self-cleaning foul-release coatings of ship hulls, Mater. Des. 101 (2016) 218–225.
[89] M.S. Selim, A. Elmarakbi, A.M. Azzam, M.A. Shenashen, A.M. EL-Saeed, S.A. ElSafty, Eco-friendly design of superhydrophobic nano-magnetite/silicone composites for marine foul-release paints, Prog. Org. Coating 116 (2018) 21–34.
[90] P. Wang, B. He, B. Wang, L. Wang, H. Yu, S. Liu, Q. Ye, F. Zhou, Durable selfpolishing antifouling coating based on fluorine-containing pyrrolidone amphiphilic copolymer-functionalized nanosilica, Prog. Org. Coating 165 (2022) 106706.
[91] A. Ansari, M. Saadatbakhsh, M. Sohrabi, S.J. Asl, N.M. Nouri, Antifouling activity of superhydrophobic PDMS/hydrophobic silica coating, Surf. Eng. 39 (1) (2023) 35–48.
[92] E. Yilgor, I. Yilg € or, Silicone containing copolymers: synthesis, properties and € applications, Prog. Polym. Sci. 39 (6) (2014) 1165–1195.
[93] M.S. Selim, A.M. Azzam, S.A. Higazy, S.A. El-Safty, M.A. Shenashen, Novel graphene-based ternary nanocomposite coatings as ecofriendly antifouling brush surfaces, Prog. Org. Coating 167 (2022) 106803.
[94] M.S. Selim, M.A. Shenashen, A. Elmarakbi, A.M. EL-Saeed, M.M. Selim, S.A. ElSafty, Sunflower oil-based hyperbranched alkyd/spherical ZnO nanocomposite modeling for mechanical and anticorrosive applications, RSC Adv. 7 (35) (2017) 21796–21808.
[95] M.S. Selim, H. Yang, F.Q. Wang, X. Li, Y. Huang, N.A. Fatthallah, Silicone/Ag@ SiO2 core-shell nanocomposite as a self-cleaning antifouling coating material, RSC Adv. 8 (18) (2018) 9910–9921.
[96] S. Xiao, X. Cao, Z. Dong, X. Ma, X. Zhang, G. Cai, A pH-responsive ceriumimidazole decorated ZIF-8 to achieve self-healing barrier property for epoxy coating on Al alloy by controlled release, Prog. Org. Coating 163 (2022) 106640.
[97] X. Cao,j. Pan, G. Cai, S. Xiao, X. Ma, X. Zhang, Z. Dong, A chemically robust and self-healing superhydrophobic polybenzoxazine coating without fluorocarbon resin modification: fabrication and failure mechanism, Prog. Org. Coating (2022) 106630.
[98] B.L. Leigh, E. Cheng, L. Xu, A. Derk, M.R. Hansen, C.A. Guymon, Antifouling photograftable zwitterionic coatings on PDMS substrates, Langmuir 35 (5) (2019) 1100–1110.
[99] H. Ghaleh, K. Jalili, B.M. Maher, R. Rahbarghazi, M. Mehrjoo, S. Bonakdar, F. Abbasi, Biomimetic antifouling PDMS surface developed via well-defined polymer brushes for cardiovascular applications, Eur. Polym.j. 106 (2018) 305–317.
[100] B. Wang, P. Wang, B. He, S. Liu, Q. Ye, F. Zhou, Fabrication of ionic liquidfunctionalized polystyrene nanospheres via subsurface-initiated atom transfer radical polymerization for anti-fouling application, Prog. Org. Coating 171 (2022) 107044.
[101] P. Wang, B. He, Y. Du, B. Wang,j. Gao, S. Liu, Q. Ye, F. Zhou, Functionalized Ti3C2Tx-based nanocomposite coatings for anticorrosion and antifouling applications, Chem. Eng.j. 448 (2022) 137668.
[102] R. Hu, G. Li, Y. Jiang, Y. Zhang,j. Zou, L. Wang, X. Zhang, Silver-zwitterion organic-inorganic nanocomposite with antimicrobial and antiadhesive capabilities, Langmuir 29 (11) (2013) 3773–3779.
[103] E.R. Silva, O. Ferreira, P.A. Ramalho, N.F. Azevedo, R. Bayon, A. Igartua, °j.C. Bordado, M.J. Calhorda, Eco-friendly non-biocide-release coatings for marine biofouling prevention, Sci. Total Environ. 650 (2019) 2499–2511.
[104] K. Feng, C. Ni, L. Yu, W. Zhou, X. Li, Synthesis and antifouling evaluation of indole derivatives, Ecotoxicol. Environ. Saf. 182 (2019) 109423.
[105] X. Wang, L. Yu, Y. Liu, X. Jiang, Synthesis and fouling resistance of capsaicin derivatives containing amide groups, Sci. Total Environ. 710 (2020) 136361.
[106] Z. Zhang, D. Xing, Q. Liang, D. Yong, X. Han, Size controllable synthesis and antimicrobial activity of poly-N, N'-[(4, 5-dihydroxy-1, 2-phenylene) bis(methylene)] bisacrylamide microspheres, RSC Adv. 4 (101) (2014) 57891–57898.
[107] S. Zhao, D. Zhang, Y. Jiang, C. Gao, L. Liu, Y. Liu, A silicone coating containing natural borneol fluorinated side chains with excellent static antifouling properties, Eur. Polym.j. 193 (2023) 112064.
[108] Y. Lin, Y. Xie, F. Chen, S. Gong, W. Yang, X. Liang, Y. Lian,j. Chen, F. Wei, W. Bai, Y. Xu, R. Jian, Bioinspired self-stratification fouling release silicone coating with strong adhesion to substrate, Chem. Eng.j. 446 (2022) 137043.
[109] K.M. Abdelsalam, N.A. Shaltout, H.A. Ibrahim, H.R.Z. Tadros, M.A. Aly-Eldeen, E.A. Beltagy, A comparative study of biosynthesized marine natural-product nanoparticles as antifouling biocides, Oceanologia 64 (1) (2022) 35–49.
[110] D. Su, X. Bai, X. He, Research progress on hydrogel materials and their antifouling properties, Eur. Polym.j. 181 (2022) 111665.
[111]j. Wu, D. Zhang, X. He, Y. Wang, S. Xiao, F. Chen, P. Fan, M. Zhong,j. Tan,j. Yang, "Janus-Featured" hydrogel with antifouling and bacteria-releasing properties, Ind. Eng. Chem. Res. 58 (38) (2019) 17792–17801.
[112] K. Zhu, D. Hou, Y. Fei, B. Peng, Z. Wang, W. Xu, B. Zhu, L. Li, H. Wang, Thermosensitive hydrogel interface switching from hydrophilic lubrication to infection defense, ACS Appl. Bio Mater. 2 (8) (2019) 3582–3590.
[113] Z. Zhu, X. Li, Silicone hydrogels based on a novel amphiphilic poly(2methyl2oxazoline)- b-poly(dimethyl siloxane) copolymer,j. Appl. Polym. Sci. 131 (3) (2014) 39867.
[114] N.Y. Kostina, S. Sharifi, A. de Los Santos Pereira,j. Mich°alek, D.W. Grijpma, C. Rodriguez-Emmenegger, Novel antifouling self-healing poly(carboxybetaine methacrylamide-co-HEMA) nanocomposite hydrogels with superior mechanical properties,j. Mater. Chem. B 1 (41) (2013) 5644.
[115] M. Li, Y. Dong, M. Wang, X. Lu, X. Li,j. Yu, B. Ding, Hydrogel/nanofibrous membrane composites with enhanced water retention, stretchability and selfhealing capability for wound healing, Compos. B Eng. 257 (2023) 110672.
[116] S. Tian, D. Jiang,j. Pu, X. Sun, Z. Li, B. Wu, W. Zheng, W. Liu, Z. Liu, A new hybrid silicone-based antifouling coating with nanocomposite hydrogel for durable antifouling properties, Chem. Eng.j. 370 (2019) 1–9.
[117] M.S. Rahaman, H. Therien-Aubin, M. Ben-Sasson, C.K. Ober, M. Nielsen, M. Elimelech, Control of biofouling on reverse osmosis polyamide membranes modified with biocidal nanoparticles and antifouling polymer brushes,j. Mater. Chem. B 2 (12) (2014) 1724–1732.
[118] L. Al-Naamani, S. Dobretsov,j. Dutta,j.G. Burgess, Chitosan-zinc oxide nanocomposite coatings for the prevention of marine biofouling, Chemosphere 168 (2017) 408–417.
[119] Q. Bao, D. Zhang, P. Qi, Synthesis and characterization of silver nanoparticle and graphene oxide nanosheet composites as a bactericidal agent for water disinfection,j. Colloid Interface Sci. 360 (2) (2011) 463–470.
[120] Y. Baek, Y. An, Microbial toxicity of metal oxide nanoparticles (CuO, NiO, ZnO, and Sb2O3) to Escherichia coli, Bacillus subtilis, and Streptococcus aureus, Sci. Total Environ. 409 (8) (2011) 1603–1608.
[121] M.J. Hajipour, K.M. Fromm, A. Akbar Ashkarran, D. Jimenez De Aberasturi, I.R.D. Larramendi, T. Rojo, V. Serpooshan, W.J. Parak, M. Mahmoudi, Antibacterial properties of nanoparticles, Trends Biotechnol. 30 (10) (2012) 499–511.
[122] X. Zhang, E. Årstøl, M. Nymark, M. Fages-Lartaud, Ø. Mikkelsen, The development of polydimethysiloxane/ZnO–GO antifouling coatings,j. Cluster Sci. 33 (6) (2022) 2407–2417.
[123] S. Soleimani, A. Jannesari, M. Yousefzadi, A. Ghaderi, A. Shahdadi, Eco-friendly foul release coatings based on a novel reduced graphene oxide/Ag nanocomposite prepared by a green synthesis approach, Prog. Org. Coating 151 (2021) 106107.
[124] M. Wang, Y. Zi,j. Zhu, W. Huang, Z. Zhang, H. Zhang, Construction of superhydrophobic PDMS@MOF@Cu mesh for reduced drag, anti-fouling and selfcleaning towards marine vehicle applications, Chem. Eng.j. 417 (2021) 129265.
[125] S. Bi, K. Xu, G. Shao, K. Yang,j. Tian, Mechanically robust antifouling coating with dual-functional antifouling strategy by infiltrating PDMS into plasma-sprayed porous Al2O3-Cu coating,j. Mater. Sci. Technol. 159 (2023) 125–137.
[126] M.S. Selim, M.A. Shenashen, A. Elmarakbi, N.A. Fatthallah, S. Hasegawa, S.A. ElSafty, Synthesis of ultrahydrophobic and thermally stable inorganic-organic nanocomposites for self-cleaning foul release coatings, Chem. Eng.j. 320 (2017) 653–666.
[127] Z. Lu, Z. Chen, Y. Guo, Y. Ju, Y. Liu, R. Feng, C. Xiong, C.K. Ober, L. Dong, Flexible hydrophobic antifouling coating with oriented nanotopography and nonleaking capsaicin, ACS Appl. Mater. Interfaces 10 (11) (2018) 9718–9726.
[128] G. Gomathi Sankar, S. Sathya, P. Sriyutha Murthy, A. Das, R. Pandiyan, V.P. Venugopalan, M. Doble, Polydimethyl siloxane nanocomposites: their antifouling efficacy in vitro and in marine conditions, Int. Biodeterior. Biodegrad. 104 (2015) 307–314.
[129] M.S. Selim, M.A. Shenashen, N.A. Fatthallah, A. Elmarakbi, S.A. El-Safty, In situ fabrication of one-dimensional-based lotus-like silicone/ϒ-Al2O3 nanocomposites for marine fouling release coatings, ChemistrySelect 2 (30) (2017) 9691–9700.
[130] M.B. Chobba, M.L. Weththimuni, M. Messaoud, C. Urzi,j. Bouaziz, F. De Leo, M. Licchelli, Ag-TiO2/PDMS nanocomposite protective coatings: synthesis, characterization, and use as a self-cleaning and antimicrobial agent, Prog. Org. Coating 158 (2021) 106342.
You have requested "on-the-fly" machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Show full disclaimer
Neither ProQuest nor its licensors make any representations or warranties with respect to the translations. The translations are automatically generated "AS IS" and "AS AVAILABLE" and are not retained in our systems. PROQUEST AND ITS LICENSORS SPECIFICALLY DISCLAIM ANY AND ALL EXPRESS OR IMPLIED WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES FOR AVAILABILITY, ACCURACY, TIMELINESS, COMPLETENESS, NON-INFRINGMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Your use of the translations is subject to all use restrictions contained in your Electronic Products License Agreement and by using the translation functionality you agree to forgo any and all claims against ProQuest or its licensors for your use of the translation functionality and any output derived there from. Hide full disclaimer
© 2024. This work is published under http://creativecommons.org/licenses/by-nc-nd/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.
Abstract
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.
You have requested "on-the-fly" machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Show full disclaimer
Neither ProQuest nor its licensors make any representations or warranties with respect to the translations. The translations are automatically generated "AS IS" and "AS AVAILABLE" and are not retained in our systems. PROQUEST AND ITS LICENSORS SPECIFICALLY DISCLAIM ANY AND ALL EXPRESS OR IMPLIED WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES FOR AVAILABILITY, ACCURACY, TIMELINESS, COMPLETENESS, NON-INFRINGMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Your use of the translations is subject to all use restrictions contained in your Electronic Products License Agreement and by using the translation functionality you agree to forgo any and all claims against ProQuest or its licensors for your use of the translation functionality and any output derived there from. Hide full disclaimer
Details
1 School of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, China
2 Instituto de Estudios Avanzados IUDEA, Departamento de Física, Universidad de La Laguna C/Astrofísico Francisco Sanchez, S/n.E-38203, Tenerife, Spain
3 State Key Laboratory for Marin Corrosion and Protection, Luoyang Ship Material Research Institute (LSMRI), Qingdao, China