Antifouling Field Research Articles

Research Progress on Using Modified Hydrogel Coatings as Marine Antifouling Materials

The adhesion of marine organisms to marine facilities negatively impacts human productivity. This phenomenon, known as marine fouling, constitutes a serious issue in the marine equipment industry. It increases resistance for ships and their structures, which, in turn, raises fuel consumption and reduces ship speed. To date, numerous antifouling strategies have been researched to combat marine biofouling. However, a multitude of these resources face long-term usability issues due to various limitations, such as low adhesion quality, elevated costs, and inefficacy. Hydrogels, exhibiting properties akin to the slime layer on the skin of many aquatic creatures, possess a low frictional coefficient and a high rate of water absorbency and are extensively utilized in the marine antifouling field. This review discusses the recent progress regarding the application of hydrogels as an important marine antifouling material in recent years. It introduces the structure, properties, and classification of hydrogels; summarizes the current research status of improved hydrogels in detail; and analyzes the improvement in their antifouling properties and the prospects for their application in marine antifouling.

High transparent antifouling material for endoscope lens by Lubricant‑infused nano re-entrant structure

Bionic lubricant material received widespread attention in the antifouling field because of its dynamic slippery surface, while the micro-nano structures construction to stable film inevitable pose a compromised optical transparency. In this study, we prepare a biomimetic lubrication material with oil-infused nano-reentrant structure. The nano-reentrant structure of the coating eliminates visible light scattering, resulting in high transparency that was comparable to bare glass. Owing to the nanostructure infused by lubricant increase the capillary force required for the liquid to detach from, this transparent material not only display excellent repellency properties, but also improves the stability of lubricated surfaces. Based on its marvelous biocompatibility, we apply it to the endoscopic lenses. Extensive procedures performed in vivo on porcine stomach showed significantly reduced fouling, resulting nearly 100% clarity. We believe that our coatings provide inspiration for the design of next-generation endoscopes used to in lesion diagnosis and treatment.

Eucalyptus spp.-inspired degradable lubricant-releasing coating for marine antifouling surfaces

Currently, slippery liquid-infused porous surfaces (SLIPS) have garnered considerable attention in marine antifouling field because of its dynamic slippery surface. However, the reduction of antifouling performance due to uncontrolled loss of lubricant limits its application. Herein, inspired by the stripping of eucalyptus bark and the secretion of essential oil by leaf gland cells, a degradable lubricant-releasing coating (DLRC) without antifouling agent is designed. The DLRC presents excellent anti-algae, antibacterial adhesion properties, and its antifouling ability has been further verified by simulation experiments. The excellent antifouling performance is mainly due to the dual role of degradation surface-renewal and the continuous seepage of lubricating oil to the surface. Compared with previously reported responsive lubricant release methods, this self-degrading controlled release method is more suitable for marine environments. What's more, the ester and lubricant content can be adjusted to meet different antifouling needs. Finally, we hope that this strategy will shed some light on the design of functional coatings.

Machine Learning Aided Design and Optimization of Antifouling Surfaces.

Antifouling surfaces, renowned for their strong surface resistance to proteins, cells, or tissues in various biological and environmental conditions, have broad applications in implanted devices, antibacterial coatings, biosensors, responsive materials, water treatment, and lab-on-a-chip. While extensive experimental research exists on antifouling surfaces, machine learning studies on this topic are relatively few. This perspective specifically focuses on exploring the complex relationships between the composition, structure, and properties of antifouling surfaces, examining how these factors correlate with surface hydration and protein adsorption. Different machine learning models have been developed to analyze and predict single and multiple protein adsorptions on various types of surfaces, ranging from structureless surfaces to well-ordered and rigid self-assembled monolayers, dynamically ordered polymer brushes, and complex filtration membranes. These models not only identify key descriptors or functional groups critical for antifouling performance (surface hydration, protein adsorption) but also predict the antifouling properties for a specific surface. Recognizing current challenges, this perspective delineates future research directions in the antifouling field. By leveraging and comparing current machine learning approaches, it aims to advance both the design and fundamental understanding of antifouling surfaces, thereby pushing the boundaries of innovation in this critical field.

Construction of copper-functionalized two-dimensional zeolitic imidazole framework-7 (ZIF-7) nanosheets for enhanced antibacterial and antibiofilm performance

Marine biological pollution restricts the sustainable development of marine economy. Cu2O stands as a predominant antifouling agent for developing marine resources engineering. However, the problems of easy aggregation, rapid failure, and explosive release of copper ions limit the practical application of Cu2O. In this work, a novel copper-functionalized two-dimensional zeolitic imidazolate framework-7 nanocomposites ZIF-7@Cu2O was successfully fabricated by in-situ growth methodology. The emergence of ZIF-7@Cu2O nanocomposites solves the above problems in the use of Cu2O. Due to the huge specific surface area of the 2D ZIF-7 nanosheets and the electrostatic interactions, the cubic Cu2O, with a diameter of 250 nm, can be uniformly and firmly anchored on the surface of 2D ZIF-7 nanosheets, thus effectively avoiding the rapid dissolution of cuprous oxide and reducing the release rate of copper ions. Antibacterial experiments demonstrate that, in comparison to ZIF-7, Cu2O, and ZIF-7/Cu2O (physical mixture of ZIF-7 and Cu2O), ZIF-7@Cu2O exhibits superior antibacterial properties with 99.99 % against E. coli and the minimum inhibitory concentration (MIC) of 32 μg/mL. Furthermore, the reactive oxygen species (ROS) assay confirms ZIF-7@Cu2O could promote the generation of ROS. Antibiofilm formation results reveal that ZIF-7@Cu2O nanocomposites are effective in preventing biofilm formation of E. coli and P. aeruginosa at a low concentration (50 μg/mL). Finally, ZIF-7@Cu2O nanocomposites are employed as fillers to prepare ZIF-7@Cu2O/EP composite coating, the bactericidal kinetics and bacterial adherence on the coating surface are investigated. We believe this work could provide novel insights into the rational design of 2D ZIF-based material in the field of antifouling.

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

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

Long lasting marine antifouling polyurethane coating chemically bonded with poly(hexamethylene guanidine)

AbstractIn order to protect the marine environment, traditional marine antifouling coatings such as tributyltin (TBT)‐based antifouling coatings have been phased out. There is an urgent need to develop environmentally friendly marine antifouling coatings. In this work, the antibacterial poly(hexamethylene guanidine) (PHMG) was introduced into polyurethane (PU) through chemical bond to prepare a green environmentally friendly marine antifouling coating (PU‐PHMG). The morphology, antimicrobial properties, mechanical properties and thermostability of the PU‐PHMG films were investigated. The antimicrobial rates of PU‐PHMG films against E. coli and S. aureus were both more than 99.9% when PHMG content in the films reached 1.0 wt%. The excellent antimicrobial activities can be maintained for more than 90 days due to the non‐leaching characteristic of PHMG. The growth of algae was also inhibited on the surface of PU‐PHMG films. The PU‐PHMG coating is promising for the applications in marine antifouling field.

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

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

P. pavoninus‐Inspired Smart Slips Marine Antifouling Coating Based on Coumarin: Antifouling Durability and Adaptive Adjustability of Lubrication

AbstractSlippery liquid‐infused porous surface (SLIPS) is received widespread attention in the antifouling field because of its dynamic slippery surface, but the limited effect of physical “anti‐adherence” and the problem of lubricant loss restrict its application for practical marine antifouling. Inspired by the self‐defensive function of P. pavoninus’s poisonous mucus, a SLIPS based on the reversible chemical bonds and the antibacterial effect of coumarin (CmSLIPS) is prepared, which addresses these disadvantages by responsively adaptive lubricity and durability. The CmSLIPS enables the “locking” and “unlocking” mode between lubricant and matrix via the reversible photodimerization of coumarin. It regulates the surface lubricity to adapt to the antifouling demand. The reversible chemical bonds of lubricant and matrix reduce lubricant loss and enhance the lubricant stability and antifouling durability. In addition to the physical anti‐adhesive barrier of SLIPS, the excellent antimicrobial property of coumarin groups further enhances the “biocidal” antifouling effect to improve long‐term antifouling durability. In summary, the CmSLIPS has surface stability, durability, responsively adaptive lubricity, efficient self‐cleaning, anti‐protein, anti‐bacterial, anti‐algae, self‐healing (92.85%) properties and 150‐day marine field antifouling performance during boom seasons, which maintains the satisfactory antifouling performance in the harsh marine environment and demonstrates the promising application in neritic sea equipment.

Ficus religiosa-inspired microstructure-controlled low surface energy coatings with long-term antifouling effect

In general, antifouling coatings based on structural design mostly use the most basic shapes such as cuboids as repeating units. In this study, four kinds of complex surface micro-structured coatings inspired by natural bifacial leaf Ficus religiosa were obtained and applied to the field of marine antifouling coatings. Based on the antifouling mechanism of surface microstructure, SiO2 @PDMS(polydimethylsiloxane)-based Ficus religiosa-like coatings (Gxy, x = D or Z, y = A or I) were prepared by the blending method and the biological template method using the same positive and negative film materials. The antifouling performances of the coatings were evaluated by mussel attachment experiments and diatom attachment experiments. Compared with pure PDMS, the anti-mussel adhesion rate of SiO2@PDMS can be as high as 73.08 %. After 8-day diatom attachment experiments, the SiO2 @PDMS-based and adaxial side-structured negative film (GDI) showed an excellent antifouling performance compared with non-structured sample, and the anti-diatom adhesion rate was 17.96. In addition, a series of surface-modified micro-structured SiO2 @PDMS-based coatings (MGxy, x = D or Z, y = A or I) were prepared from the perspective of low surface energy. The surface energy of MGxy is between 19.62 and 29.95 mJ/m2, and the surface energy after diatom attachment experiment is between 13.51 and 22.23 mJ/m2. The structure, hydrolysis-condensation modification, hydrolysate and the effect of structure on hydrolysate were analyzed by the results of diatom attachment experiment. The importance of structure and the complementary effect of structure and modification on antifouling performance were explained again. Among them, the modified SiO2 @PDMS-based and abaxial side-structured positive film (MGZA) showed the best anti-diatom performance. After 8 days diatom attachment experiment, the anti-diatom adhesion rate of MGZA was as high as 90.78 %. Moreover, the newly discovered microstructural units on GDI and MGZA were parameterized. The results of this study provide insights for further research and long-term application of bionic microstructure and surface modification in the field of antifouling.

Silver nanoparticle coupled Cu2O/Ag/Bi2MoO6 Z-scheme heterojunction with enhanced visible light photocatalytic activity for bacteriostasis

The construction of heterojunction has been considered as an effective strategy to achieve charge separation and improve photocatalytic activity. In this work, stable reduced Cu2O/Ag/Bi2MoO6 (Cu2O/Ag/BMO) nanocomposites with high-efficiency antibacterial activities were synthesized via a simple wet chemical method. After illumination of 30 days, Cu2O/Ag/BMO still showed excellent antimicrobial capability against P. aeruginosa and S. aureus. The photoluminescence spectroscopy was used to analyze the electrons and holes recombination efficiency of samples, which suggested Cu2O/Ag/BMO could promote electron-hole separation and extend the lifetime of photogenerated carriers. The results of photocurrent responses test suggested that the photocurrent density of Cu2O/Ag/BMO was four times stronger than the Cu2O, which indicated the higher separation efficiency of electrons and holes pairs for the formed Cu2O/Ag/BMO. Besides, density functional theory proved that Ag nanoparticles could promote the electrons transfer from the Bi2MoO6 layer to the Cu2O layer which facilitated the separation of photogenerated electron-hole pairs. Therefore, electrons and holes could better participate in the redox reactions and then generate more active substances (•OH and •O2–), improving the antimicrobial ability. Therefore, the prepared Cu2O/Ag/BMO composites has a great application prospect in the antifouling field.

BiOI@CeO2@Ti3C2 MXene composite S-scheme photocatalyst with excellent bacteriostatic properties

As an influential antifouling material, photocatalytic materials have drawn attention increasingly over recent years owing to their potential bacteriostatic property in the domain of marine antifouling. Herein, a flower-like BiOI@CeO2@Ti3C2 S-scheme photocatalyst was contrived and prepared by hydrothermal method. The innovative combination of Ti3C2 and narrow band gap semiconductor BiOI was implemented to modify CeO2 and the photocatalytic bacteriostatic mechanism of BiOI@CeO2@Ti3C2 was elucidated. Schottky junction was formed between CeO2 and Ti3C2, and a p-n junction was formed between CeO2 and BiOI. By photoelectrochemical characterization, BCT-10 exhibits the best photoelectrochemical performance of which photogenerated carrier transport can be performed more readily at 10 % CeO2@Ti3C2 addition. 99.76 % and 99.89 % of photocatalytic bacteriostatic efficiency of BCT-10 against Escherichia coli and Staphylococcus aureus were implemented respectively, which were 2.98 and 3.07 times higher than that of pure CeO2. The ternary heterojunction can suppress photogenerated electron-hole complexes more effectively and enhance the photocatalytic bacteriostatic effect of CeO2, which also provided a new concept to the further broadened application of CeO2 in the marine bacteriostatic and antifouling field.

Hydrophilic tyrosine-based phenolic resin with micro-ripples morphology for marine antifouling application

Since biofouling challenges negatively influence the marine and transportation industries, developing effective antifouling materials have attracted extensive concern. A tyrosine-based antifouling phenolic resin (TPP resin) was synthesized using tyrosine as a natural phenol source. TPP exhibited shell-like surface morphology with micro-ripples and excellent anti-adhesion properties against bacteria and diatom. The micro-ripples surface might be caused by the strong hydrogen bonding or ionic interaction among tyrosine units resulting in microphase separation during the curing process. Tyrosine content in TPP resin has a great influence on the surface properties, morphology and antifouling characteristics. The higher the tyrosine content, the higher is the surface hydrophilicity, the denser and more regular is the micro-ripples morphology, and the stronger is the antifouling performance. TPP-60 % exhibited the best antifouling performance. Combination of the surface hydrophilicity and regular micro-ripples surface morphology afford TPP excellent antifouling performance. TPP resins offer a broad prospect for developing phenolic resin in the antifouling field.

Hagfish‐inspired Smart SLIPS Marine Antifouling Coating Based on Supramolecular: Lubrication Modes Responsively Switching and Self‐healing Properties

AbstractSlippery liquid‐infused porous surface (SLIPS) has received widespread attention in the antifouling field, while its controllability of surface lubricity and durability of lubricant are relatively insufficient. In this study, inspired by the hagfish's defensive behavior of secreting mucus to escape from predators, a smart SLIPS marine antifouling coating is prepared, which possesses responsively switching lubrication modes and self‐healing property. The responsive supramolecular interaction between azobenzene (Azo) and α‐cyclodextrin (α‐CD) is introduced to regulate the lubricity of SLIPS. cis‐Azo is converted to trans and combined with α‐CD by supramolecular interaction under visible light or heating, driving the shrinkage of polymer chains to squeeze the stored lubricant to the surface. The responsive self‐replenishment of lubricant can adjust the surface lubricity to switch antifouling modes between “enhancive” and “normal” smartly, which adapts to different occasions. Moreover, disulfide and hydrogen bonds are introduced to enhance self‐healing performance (91.73%). In summary, it has efficient self‐cleaning, anti‐protein, antibacterial, anti‐algae properties, and 180‐day real marine field antifouling performance during boom season (the longest antifouling period in real marine field test of reported SLIPS materials), which demonstrates the promising application in neritic sea equipment and other antifouling fields.

Crawling and adhesion behavior of Halamphora sp. based on different parts of Folium Sennae-like film: Evaluation of analytical methods for anti-diatom experimental results

Anti-diatom testing is a basic method to evaluate the anti-fouling performance of coatings. Many existing results of anti-diatom performances are evaluated based on their attachment number or coverage area, ignoring the influence of the crawling and adhesion behavior of diatoms on the analysis results. Here, a Folium Sennae-like film with multiple structural units was prepared by considering the influence of diatom attachment behaviors on the analysis results. The anti-diatom performances of different parts (divided and called four parts: edge, surface, cross striation, and vertical pattern) on the Folium Sennae-like film were evaluated using the counting and area methods. Obviously, the anti-diatom performance of the Folium Sennae-like film was superior to that of epoxy resin without structure. Under equal areas, the average numbers of diatoms on the cross striation and the vertical pattern were similar to the surface. It was found that the attachment behavior of Halamphora sp. is affected by microstructure units, rather than the combined structure of which the scale is much larger than that of diatoms. Meanwhile, the average attachment area for the unit number of diatoms was calculated. The diatom attachment area without microstructure, surface, cross striation, or vertical pattern was 81.751, 106.950, 73.904, and 84.376 μm2, respectively. Moreover, the static and dynamic motion behaviors of Halamphora sp. were studied, and the theory for Halamphora sp. attachment was modeled in three dimensions. The variable morphology of Halamphora sp. lead to inaccurate results for diatom analyses based on the counting and area methods, which is summarized here. This study discusses the evaluation method of coatings by anti-diatom performance, further promoting the research of diatoms in the field of antifouling.

Preparation and Self-Cleaning Performance of Carbon-Based Superhydrophobic Coatings Based on Non-Fluorine and Non-Toxic Corn Straw.

Recently, superhydrophobic surfaces with self-cleaning ability have attracted broad research interest due to their huge potential in daily lives and industrial applications, but the use of fluorinate, toxic organic compounds, and expensive feedstocks make superhydrophobic materials a great challenge in practical application. In this study, we present a facile dip-coating strategy to prepare superhydrophobic coatings with self-cleaning properties based on a non-fluorine and non-toxic system by using eco-friendly corn straw as raw material. During this process, aromatic carbon particles with rough hierarchical structures were prepared firstly via a simple fast pyrolysis process, followed by modification with polydimethylsiloxane (PDMS) in absolute ethanol solvent to decrease the surface free energy. Research shows these natural straw-derived carbons display a microstructure of several protrusions which is similar to the lotus leave’s and the resulted coatings exhibit an outstanding superhydrophobic property with a static water contact angle (WCA) of 151.67 ± 1.36 degrees. In addition, the as-prepared coatings possessed excellent self-cleaning performance: no contaminations were observed on the surfaces after examining with sludge, calcimine, water, and common liquids such as tea, milk, soybean milk as well as ink, which have a broad range of potential application in the field of antifouling, waterproofing, and anticorrosive.

The mussel-inspired micro-nano structure for antifouling:A flowering tree

Mussels are typical marine fouling organisms that attach to surfaces though secretions, which is generally the focus of research on mussel-related fouling. This study reveals “a flowering tree” structure on mussel shells with antifouling performance. Based on the antifouling mechanism of surface microstructure, we prepared mussel-like shells (P) using the biomimetic replication method. Mussel adhesion experiments were conducted to examine the anti-mussel performances of the mussel shells and P. The anti-diatom performances of the mussel-like shells were also evaluated using three types of diatoms. The mussels responded differently to different locations on the shells, and the flowering tree microstructure exhibited excellent antifouling performance. In addition, VP (P immersed in vinyl silicon oil) and HP (P immersed in hydroxyl silicone oil) were prepared. The anti-diatom performance of VP was better than those of P and HP, indicating that hydrophobicity has a greater influence on anti-diatom performance than electronegativity. The newly discovered antifouling micro-nano structure was parameterized, revealing that a branch of the flowering tree has an inclination of 13.3° to the surface with a height of 210.1 nm. The results of this study provide insights for further investigations of bionic micro-nano structures in the field of antifouling.

A Stable and Indurative Superhydrophobic Film with Excellent Anti-Bioadhesive Performance for 6061 Al Protection.

Superhydrophobic surfaces have attracted intensive attention in the antifouling field because of their excellent anti-bioadhesive performance and environmental friendliness. However, promising surfaces have met great challenges of poor mechanical robustness under harsh serving conditions. Herein, an organic-inorganic composite strategy, that the silane-modified TiO2 nanoparticles are compounded into the porous framework provided by the stable and indurative aluminum oxide film, is proposed to address the common serious problem in superhydrophobic surfaces. Different from the traditional superhydrophobic surfaces, this composite film possesses a ~18 μm thick layer which can provide strong support to silane-modified TiO2 nanoparticles. The resulting film can reserve superhydrophobicity to the surface even after a thickness loss of ~15 μm under continuous abrasion. At the same time, the results of the bacterial adhesive tests also verify that the film has the same long-term anti-bioadhesive performance. The film with superhydrophobicity, excellent anti-bioadhesive property, and stable robustness will make it a promising candidate for serving in a harsh environment, and the design concept of this film could be applied to various substrates.

Phidianidine A and Synthetic Analogues as Naturally Inspired Marine Antifoulants.

Stationary and slow-moving marine organisms regularly employ a natural product chemical defense to prevent being colonized by marine micro- and macroorganisms. While these natural antifoulants can be structurally diverse, they often display highly conserved chemistries and physicochemical properties, suggesting a natural marine antifouling pharmacophore. In our current report, we investigate the marine natural product phidianidine A, which displays several chemical properties found in highly potent marine antifoulants. Phidianidine A and synthetic analogues were screened against the settlement and metamorphosis of Amphibalanus improvisus cyprids, and several of the compounds displayed inhibitory activities at low micromolar concentrations with IC50 values down to 0.7 μg/mL observed. The settlement study highlights that phidianidine A is a potent natural antifoulant and that the scaffold can be tuned to generate simpler and improved synthetic analogues. The bioactivity is closely linked to the size of the compound and to its basicity. The study also illustrates that active analogues can be prepared in the absence of the natural constrained 1,2,4-oxadiazole ring. A synthetic lead analogue of phidianidine A was incorporated in a coating and included in antifouling field trials, where it was shown that the coating induced potent inhibition of marine bacteria and microalgae settlement.

Secretion mechanism and adhesive mechanism of diatoms: Direct evidence from the quantitative analysis

Diatoms are one of the biofouling species attached to the substrate that can cause substrate corrosion, fuel consumption and destruction of the ecological balance. Therefore, the study of single-cellfouling organisms, particularly, the quantitative analysis of extracellular polymeric substances (EPS) is essential for antifouling. Atomic Force Microscope (AFM) was used to quantify three types of diatoms: Nitzschia closterium (N. closterium), Phaeodactylum tricornutum (P. tricornutum) and Halamphora sp. The situation of N. closterium was analyzed multiple times and the results showed that the adhesion value range of N. closterium with nacked chromatophores was three times larger than the mature one. The discovery of the EPS secretion from chromatophore is discussed in this paper, and the proposed mechanism has special implications to study the adhesive protein. Adhesion capabilities of different diatom genera and species were revealed as well. The average adhesion values of N. closterium, P. tricornutum and Halamphora sp. were about 1.7 nN, 3.3 nN and 2.5 nN, respectively, which suggest P. tricornutum could be a better candidate for testing diatom resistance on epoxy materials in the lab. Experimental data and discussions in this paper provide insights for further study of diatoms in the field of antifouling.