Preparation And Research Of Bionic Super-hydrophobic Surface

This paper analyzes and summarizes the relevant theories of super-hydrophobic, covers the preparation methods,with particular focus on the latest two years,expounding different ways to fabricate rough surfaces and low-surface-energy modifications. In addition, the study and application of new type of functional super-hydrophobic surface as well as the direction for future development are also discussed.In this work, a new, simple and convenient super-hydrophobic surface preparation method was reported in this article, and obtained super-hydrophobic films on the glass substrates. The super-hydrophobic polystyrene films have been prepared by phase separation technique. Polystyrene, prepared by bulk polymerization, was dissolved in tetrahydrofuran, and then added ethanol into the solution to induce phase separation. The microstructures of the polystyrene films were controlled by phase separation, which was enhanced properly by the concentration of ethanol. The surface morphology of the films, observed by environmental scanning electron microscope, is similar to that of the lotus leaf. The contact angle and roll angle were151.6°and 8.2°, which revealed excellent super-hydrophobic property. The phase separation method employed in this study offers the advantage of simple process, well repeatability, and low cost. To further enhance the property of super-hydrophobic films, styrene and 2, 2, 3, 4, 4, 4-hexafluorobutyl methacrylate copolymers were synthesized by bulk polymerization, and the super-hydrophobic copolymer films were prepared subsequently using phase separation technique. The copolymer was dissolved in tetrahydrofuran, and then added ethanol into the solution thereafter, to induce phase separation. The microstructures of the polymer films were controlled by the degree of phase separation, which was enhanced properly by the concentration of ethanol. The surface morphology of the films, observed by environmental scanning electron microscope, is similar to that of the lotus leaf. The contact angle and sliding angle were measured as 154.3o and 5.8o, respectively. The excellent super-hydrophobic property demonstrated that the phase separation technique is useful for preparing lotus-like fluoropolymer films.At the same time, this paper also studied the preparation of amphiphilic block copolymer based on atom transfer radical polymerization (ATRP). We report a simple method for the preparation of the super-hydrophobic copolymer (PS-PHFMA) surface by taking advantage of the features of the two blocks. It is well known that micelle will be formed when dispersing a copolymer in a selective solvent as a result of the different solubility of the blocks. And phase separation will always occur as solidifying a polymer solution in humid air. Meanwhile, PHFMA prefers to segregate on the surface of copolymer containing PHFMA block due to its low surface energy and poor miscibility with other polymers. We find that a rough surface with low surface tension, which exhibits super-hydrophobicity, can be facilely fabricated in one step by casting the micellar solution of PS-b-PHFMA inhumid air based on the cooperation of vapor-induced phase separation and surface enrichment of PHFMA block. The contact angle and sliding angle were measured as 152.3o and 8.5orespectively, which exhibited excellent super-hydrophobic property.The results of the investigation in this thesis indicated that, the techniques and the factors in the process all have direct influence on the surface micro-structures, and the surface micro-structure and constituent determined the super-hydrophobicity of the films.