Antifouling Technology Of Low Surface Energy And Bio-inspired Microstructure

A novel antifouling method and the corresponding coatings were developed in this thesis to overcome the problems in marine antifouling coatings. The antifouling method, inspired by lives in nature with antifouling capability, combined the contributions of both the low surface energy property and surface microstructures. Based on that, in this thesis we mainly focused on the preparation and characterization of new kinds of antifouling coatings of environmental friendly, high efficient, and nontoxic. Novel polymers with low surface energy were firstly synthesized by integration of the characteristics of silicone and fluoropolymer; then its properties of adhesion force and water resistance are improved greatly by an organic-inorganic hybrid preparation process; finally, a micro-nano binary structures were constructed on the surfaces of the coatings by doping siclia nanoparticles in the polymers, which combines the merits of low surface energy and microstrcutres. Moreover, we proposed a facile and fast characterization method, together with contact angle and seawater exposure tests, to evaluate the antibiofouling effects of our resulted coatings. We also discussed the feasibility that the contact angle be used as a preliminary evaluating parameter.New kinds of polymers with low surface energy were synthesized for the first time: fluoro-acrylate polymer (FPA) with -OH, and polysiloxane modifying polyurethane prepolymer with -NCO (SPU). Then FPA - SPU was synthesized by linking reaction between FPA and SPU. This unique polymer is much better than FPA or SPU with unique properties of flexility and ultralow surface energy of a contact angle of about 103°, which originated form the combination of strongpoint of silicone and fluoropolymer in its molecular structures. Further, Si-O networks were introduced into the resulted FPA-SPU polymer by acid catalyzed sol-gel method and achieved FPA - SPU/SiO₂ organic-inorganic hybrid materials. Their high crosslinking density originated from interpenetrating polymer network enabled them improved adhesion force and water resistance and higher contact angle of 109°.Inspired by the special structures on the epidermis of some lives with antifouling capability, we constructed a micro-nano binary structures on the surfaces of FPA-SPU polymer by doping them with nanoparticles. Its contact angle was increased to above 150°and in sharp contrast to the contact angle of 109 for undoped polymer. This simple and facile method integrated the polymer of low surface energy with surface microstructures, hence it involved no complicated equipments or instructions and is suitable for coating ships cost-effectively in large areas. To test the antifouling performances of the resulted coatings, a simple and efficient lab-used evaluation method based on contact angles was proposed and used to analyze the possibilities affecting the antifouling performances measured in sea areas of Qingtao and Sanya. By comparison the contact angles with the lab-used evaluation method as well as the antifouling experiments, our technique was proved to be a qualified method for evaluating the antifouling properties. Also, its accuracy and reliability are further examined.