Preparation of low surface energy antibacterial coatings with micro- nano structure and the application prospects of the coatings in marine anti-biofouling

The adhesion of marine microorganisms to the surface of hulls and marine engineering facilities will induce a lot of serious problems. Therefore, the surface needs antifouling treatment, and the bionic materials with micro - rough surface microstructure can be applied in marine anti-biofouling. A series of hydroxy-terminated polybutadiene (HTPB) polyurethanes with different hard segment contents was synthesized by prepolymer method, then blended with epoxy resin, and the polymer coating with microstructure is prepared by cross-linking curing with amine cross-linking agent. The anti-biofouling and antibacterial properties of the low surface coating have been studied. The characterization analysis of the system was carried out through infrared (FTIR), ultra-depth of field three-dimensional microscope, contact angle measuring instrument and antibacterial test. The results show that the HTPB polybutadiene has formed a hill-like microstructure in the epoxy resin, the microstructure size is controllable, and the hydrophobic low surface energy coating can be prepared. There are regularly arranged microstructures with different sizes on the PU/EP coating surface with different hard segment contents. The maximum of the static water contact angle of the sample numbered HPE10 is 102 degrees. Compared with pure PU and pure EP coatings, the static water contact angles of the micro-structured coatings are significantly increased, indicating that the coating has low surface energy and hydrophobicity, and the static water contact angle of the PU/EP coating is significantly increased after rubbing with sandpaper, up to 117 degrees. Escherichia coli, Staphylococcus aureus, Vibrio natriegens and Citrobacter farmeri were selected for antibacterial tests, and the antibacterial test showed that the coating has high antibacterial properties against Escherichia coli and Staphylococcus aureus. This kind of antibacterial coating with low surface energy has good prospects for marine application development.