Preparation Of Bionic Microstructure Coating And Its Marine Antifouling Performances

The invasion of marine fouling organisms will lead to higher ship load and energy consumption.Meanwhile,it provides microbial dependent space to accelerate the corrosion process.Therefore,it is very important to prepare coatings that can inhibit the adhesion behavior of fouling organisms.The application of bionics to marine antifouling coatings has become a hot spot.Among them,the research on natural microstructures has gradually deepened,but the relationship between the size,behavior and microstructure of fouling organisms and modification conditions is still unclear.Therefore,based on the size of fouling organisms,this paper explores the surface of animals and plants with different orders of magnitude of microstructure size.Meanwhile,the surface of coatings imitates the natural microstructures and combines the bio-inspired injection liquid,assembly of active substances and low surface energy methods to improve the antifouling performance of the modified coating.Finally,the anti-fouling performance of the Folium Sennae-like coating,the Ficus religiosa-like coating and the mussel shell-like coating was improved.Based on the design of gradient microstructure units,the relationship between the microstructure and the modification conditions was explored,and the array coating of the microstructure unit with the best anti-fouling performance in the bionic coating was obtained.The effect of microstructure on the antifouling performance of the coating was studied.The main research contents are as follows:The biomimetic Folium Sennae coating(PDMS-PSFS)was prepared by biological template method and two microstructure units were obtained.They are convex polyhedron with a side length of about 20μm and a height of about 3.9μm and jujube-like structures with a long axis of about 10～20μm and a depth of about 8.4μm.The adhesion behavior of Halamphora sp.with a size of about 17.5μm on the coating surface was studied.The number of diatoms attached to the surface,vertical pattern and cross striation of the coating with uniform microstructure units is 32,33 and 36,respectively,indicating that the adhesion results of Halamphora sp.are finally consistent with the minimum microstructure unit.It was found that the attachment morphology of Halamphora sp.was greatly affected by the structure,and the attachment area threshold on the structured surface was[80,120]μm~2,and there were six main attachment situations.Furthermore,the Folium Sennae-like coating(FSF)with higher reduction degree was obtained by the optimized biological template method,and three microstructure units of convex polyhedron,jujube like and tapered rod were obtained.Among them,the tapered rod structure can be regarded as two parts of the cylinder and spheres.The diameter of the bottom surface of the cylinder is about 9μm,the average height is about 60μm,the diameter of the sphere is about 2μm,and the center distance between the spheres is about2μm.There is almost no diatom attached to the tapered rod structure,showing extremely prominent antifouling performance.At the same time,different ratios ofα-L-Rhamnopyranose monohydrate and Sennoside A were assembled on the surface of FSF.When the assembly concentration ofα-L-Rhamnopyranose monohydrate was 0.100 g/m L,theα-L-Rhamnopyranose monohydrate coating/Sennoside A coatings AGFSF-2 and AGFSF-5 have better antifouling effect,and the anti-diatom adhesion rate of AGFSF-5 on the second day was as high as 94.85%.The imitation Ficus religiosa coating(Gxy)was prepared by combining blending method and biological template method,and the adaxial side and abaxial side opposite and corresponding microstructure coatings with the Ficus religiosa were obtained.All the microstructure units have a structure similar to the size of the Halamphora sp.and a structure with an order of magnitude different in size.The microstructure unit on the GDI of the adaxial side-like negative film is like a five-petal flower,with an external flower-like contour structure and a fingerprint-like internal structure.The width of the convex contour is about 2.50μm and the height is about 2.00μm.The internal structure distance of the fingerprint is 1.00～2.00μm.The microstructure unit on the GZA of the abaxial side-like positive film is a convex two-layer microstructure with a divergent structure.The transverse gradient between the two layers is about 2.00～6.00μm,and the short axes of the bottom and top layers are about 20μm and 15μm,respectively.The height difference of the divergent structure centered on the double-layer convex structure is about 3.50μm,and the width of the convex is about 5μm.A low surface energy modified coating was obtained by hydrolysis-condensation method.The anti-diatom adhesion rates of GDI and GZA on the 6th day were 74.25%and 81.00%,respectively,and the anti-diatom adhesion rate of the modified abaxial side-like positive film MGZA with a surface energy of 14.41 m J/m~2 was still as high as 90.78%on the 8th day.The mussel-like shell coating(PF)was obtained by the bio-template method,and the microstructure unit with a size smaller than that of the Halamphora sp.was obtained.The microstructure unit is similar to pine tree.The diameter of branch and trunk is about 2.13μm,the inclination of branch and trunk is about 7°,the spacing between branches is 19.15μm,the inclination of branch and surface is 13.3°,and the height is 210.1 nm.This structure has a significant guiding effect on the attachment of Halamphora sp.,that is,Halamphora sp.selectively attaches to the branches of the branch.The mussel-like shell VP injected by vinyl silicone oil and the mussel-like shell HP injected by hydroxyl silicone oil were obtained by liquid injection method.The contact angle ranges of PF,HP and VP are 70°～120°,30°～80°and80°～110°,respectively.The wettability is mainly determined by the properties of the modified silicone oil itself.After modification,the algae still maintains the original law of selective attachment,and the ability to inhibit diatom attachment is VP>PF>HP.The cylindrical array templates with corresponding heights of about 5.0μm,11.0μm,14.0μm and 17.0μm and diameters of about 60.0μm were obtained by laser etching technology,and the gradient microstructure coating(Mx Fy)was obtained by template method.Mx Fy was modified by liquid injection method,low surface energy treatment and assembly of active substances to obtain VMx Fy,MMx Fy and AGMx Fy.It was found that all microstructure units inhibited the adhesion of mussels,and the anti-adhesion ability of mussels was MPF-2>MNF-2>MNF-3.The results of anti-diatom adhesion ability were MNF-2>MPF-1>MNF-4>MPF-4>MNF-1>MNF-3>MPF-2>MPF-3.Among the three series of modified samples,VMx Fy had the best antifouling performance,and the lowest anti-diatom adhesion rate was96.12%on the 8th day.The anti-diatom adhesion rate of MMNF-3 in MMx Fy series was as high as 95.6%on the 8th day,and the anti-diatom adhesion rate of AGMNF-1 in AGMx Fy series was the highest on the 8th day,which was 74.01%.