Research On Marine Antifouling Performances Of Biologic Surface

Any marine structures such as ship hulls, jetties and platforms are subject to diverse and severe biofouling, which restricts their applications and results in tremendous expense. Traditional toxic antifouling coating can prevent marine organisms fouling effectively, but it also causes serious pollution to the marine environment. As more attention is payed to protecting the marine environment, the research and development of high efficient, broad-spectrum, non-toxic antifouling paint is imperative. Many marine foliages and animals have environmental friendly and ingenious antifouling properties, which accord with the trend of antifouling technology.Inspired from nature, different antifouling quomodos of representative biologic surfaces were studied firstly. Then, biomimetic coatings were prepared and modified based on nature antifouling quomodos. Finally, efficient evaluation methods of testing the antifouling performances were established and the antifouling performances of different man-made coatings were analyzed by academic methods, such as attachment point theory, fracture mechanics, adhesion model, etc. The major work of this dissertation is summarized as follows:Firstly, some testing methods of scan electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), gas chromatography (GC)-mass spectrum (MS), etc and investigation method were used to study representative biologic surfaces, including land foliages (lotus leaves, Cinnamoum camphora (Linn.) leaves, Bauhinia blakeana Dunn leaves), chondrichthyes, osteichthyes, mangrove plants, macroalgae, etc. Beneficial biomimetic factors were aslo summarized based on these reseach.Secondly, polydimethyl siloxane (PDMS) was chosen as matrix material and five different types of biomimetic PDMS surfaces were prepared and charactered.①Coatings of different elastic modulus were prepared by doping 5%, 10%, 15% weight percent silicon dioxide nanoparticles into the PDMS matrix.②Based on the soft lithography and casting, PDMS surfaces with different microtopographies were obtained by using five different types of metallographic abrasive paper as templates and replicating them.③Different coloured PDMS coatings were prepared by coating PDMS liquid on different coloured paint surfaces.④Coatings with diffuse lubricant surfaces were prepared by adding silicone oil with similar structure and low surface energy into PDMS matrix.⑤Three kinds of materials of polytetrafluroethene (PTFE), polymethyl methacrylate (PMMA) and PDMS were chosen as different surface energy coatings.Thirdly, diatom (Nitzschia closterium f. minutissima) attachment experiment, macrofouler (Chthamalusc hallengeri Hoek) attachment experiment and marine immersion experiment in sea area of Qingtao were used as evaluation methods of testing the antifouling performances, the influence of elastic modulus, sueface microtopography, colour, diffuse lubricant and surface energy on antifouling performances was studied by these evaluation methods. The results show that elastic modulus has influence on adhesive strength and fracture types of fouling organisms, low elastic modulus coating is advisable. Microtextured surface does not have obvious antifouling performances compare to slippery surface. Silicone oil can diffuse to the surface of the coating and improve the antifouling performances remarkably. Colour has influence on antifouling performances, antifouling paints with excellent colour could be prepared based on the main fouling organisms in corresponding sea area. Effect of surface energy on attachment of fouling organisms is complicated, no linear relationship is found, a certain surface energy numerical value range in which the surface has the least adhesive strength is existent in theory.This dissertation makes chear antifouling mechanisms of biologic surfaces theoretically, the work makes theoretical preparations for the development of novel non-toxic antifouling coatings.