Research On Preparation And Performance Of Hydrophobic Bionic Multifunctional Coatings

Wettability is one of the important component of the surface properties of materials.There are many organisms in nature that have different wettability,and people have taken inspiration from it,and their surfaces have been studied in depth.In addition to hydrophobic or superhydrophobic properties,biological surfaces with special wettability also have other functions,including self-cleaning,anti-fouling,anti-icing,anti-corrosion and oil-water separation,etc.Therefore,it is of great research value and significance to develop functional surfaces according to different production requirements.At present,the traditional methods of preparing functional surfaces with special wettability have many disadvantages,such as high cost,complex preparation process,immature technology,unstable performance and environmental pollution,which seriously restrict the application of wettability surfaces in production and life.In this paper,a simple,low-cost,stable and efficient pneumatic spraying method is adopted to design and prepare bionic graphene anticorrosion coating,fluorine-free multifunctional superhydrophobic coating and water-based superhydrophobic coating respectively.Metal corrosion for Marine environment protection problems,we will adopt the way of step spraying anti-corrosion coatings coating to metal substrate surface,preparation of a kind of bionic graphene anti-corrosion coating with hydrophobic properties,corrosion resistance properties of the coating with a strong,high level of adhesion strength and hardness level,at the same time have a certain self-cleaning performance.Spraying coating process can get rid of the restriction of the base shape and area,and the operation is simple.The surface of the coating is smooth and the wanter contact angle（WCA）of the coating is 105°,and it shows a good self-cleaning effect.The hardness of the coating is up to 4H,the binding force is more than 2 levels,the neutral salt spray test time is more than 173d,and the corrosion current density in the potentiometric polarization curve decreases by more than 2 orders of magnitude.In addition,you can also adjust the color of the paint by adding different colors of iron oxide pigments to meet the requirements of appearance color in production and living applications.Inspired by the special wettability of lotus leaf in nature,the microparticles of Melamine Phosphate（MPP）and Dipentaerythritol（DPER）were hydrophobic modified by Hexadecyltrimethoxysilane（HDTMS）and mixed with nano-sized Si O₂to prepare the superhydrophobic surface with micro-nano structure.The water contact angle（WCA）of the coating surface is 161.5°and the sliding angle（SA）is 3.2°.The analysis of microstructure and chemical composition shows that the superhydrophobic properties of the coating are determined by both microstructure and chemical composition.Coatings prepared by the same spraying method on different hard（tinplate,copper mesh,glass sheet）and soft（A4 paper,cotton fabric）substrates all have superhydrophobic properties.After 3m sand paper friction and wear test and p H=1 and p H=14 acid soaking for 5 days,the surface water contact angle of the coating is still above 150°,showing excellent mechanical durability and chemical stability.In addition,the coating has excellent self-cleaning performance,antifouling performance and efficient and stable oil-water separation ability,in which the separation efficiency of oil-water mixed solution and 1mol L^-1acid-base environment is more than 95%.The coating also has excellent anti-icing and anti-corrosion properties.Compared with the blank substrate,the freezing time of water droplets on the surface is prolonged by 250s,and the corrosion protection efficiency of superhydrophobic coating on the substrate is more than 98.1%.In addition,the cotton fabric coated with superhydrophobic coating has the ability of flame retardant and self-extinguishing.Based on the previous research,deionized water was further used as the solvent,waterborne epoxy resin,Hexadecyltrimethoxysilane（HDTMS）modified Ti O₂and Si O₂and polytetrafluoroethylene aqueous solution were added,and waterborne superhydrophobic coating was also prepared on tinplate by pneumatic spraying.It is observed that the surface of the water-based superhydrophobic coating is lamellar,granular and filamentous composite rough structure.The water contact angle（WCA）and sliding angle（SA）of the coating surface are 163.5°and 3°.After 12m sand paper friction and wear test,p H=1 and p H=14 acid soaking test for 7 days,the surface contact angle of the coating is still above 150°,which has excellent mechanical durability and chemical stability.In addition,the glass sheet and copper mesh coated with water-based superhydrophobic coating exhibit excellent self-cleaning ability and oil-water separation ability（the oil-water separation efficiency is more than 95%）,respectively.