Preparation And Properties Of Epoxy-based Superhydrophobic Coating

The superhydrophobic surface has potential use value in the fields of fluid drag reduction,self-cleaning,and anti-icing due to its special wetting properties.Rough structure and low surface free energy are two necessary factors for the material surface to achieve superhydrophobicity.Based on these two factors,researchers have proposed methods for preparing superhydrophobic surfaces such as sol-gel,etching,and electrospinning.However,these methods have the disadvantages of complicated operation and expensive equipment,making it difficult to achieve large-area preparation of superhydrophobic surfaces.Therefore,how to simplify the preparation process and reduce the cost is of great significance for the application of superhydrophobic surfaces.This paper combines the two necessary factors of superhydrophobic surface to prepare a superhydrophobic coating with rough structure on glass substrate.The suface morphology and chemical composition of the coating were characterized by means of SEM and FI-IR,and the surface wetting,self-cleaning,chemical resistance,and mechanical properties were tested.The details are as follows:?1?The EP/PDMS-DTES/SiO₂ coating with a rough structure and a low surface free energy is prepared by an organic-inorganic hybrid method.When EP=0.2g,m-SiO₂/n-SiO₂=1.8g/0.3g,the rough structure of the coating surface can be fully exposed and the coating has excellent bonding force with the substrate,so that the coating exhibits excellent mechanical properties and high static water contact angle,WCA=152.5^o.In addition,performance tests show that the coating has excellent self-cleaning and chemical resistance.?2?The EP/ZnO solution was dropped on the surface of the substrate to prepare an EP/ZnO coating with a secondary structure,and then the coating was modified with stearic acid to obtain an EP/ZnO/STA superhydrophobic coating.When m-ZnO/n-ZnO=1.84g/0.36g,C_?STA?=6wt%,the modification time is 6min,the contact area between the water droplet and the coating is the smallest,the hydrophobicity is the best,the static water contact angle WCA=153.12^o.Through the performance test,it was found that the superhydrophobic coating has excellent self-cleaning and chemical resistance,at the same time,the coating has good adhesion with the substrate so that the coating exhibits excellent mechanical properties.?3?The self-made m-EP and modified n-SiO₂ are mixed with the hydrophobically modified epoxy resin solution and drip coated on the substrate to obtain EP/m-EP-SiO₂/DTES coating with micro/nano structure.the effects of m-EP/n-SiO₂mass ratio and EP content on wettability of coatings were discussed.when EP=0.25g and m-EP/n-SiO₂=1.4g/0.4g,the coating exhibits excellent mechanical properties and superhydrophobicity,and the coating has excellent self-cleaning and chemical resistance through performance tests.