Preparation Of Stable Superhydrophobic And Superamphiphobic Coatings By Dip-coating And Their Applications

Superhydrophobic and superamphiphobic surfaces have potential applications in many fields,but are seriously hindered by their complicated preparation methods and low mechanical stability.Thus,it is highly challenging to develop novel strategies for efficient preparation of robust superhydrophobic and superamphiphobic surfaces on various substrates,Also,such studies have great scientific and practical significance for the development of superhydrophobic and superamphiphobic surfaces.In this study,we realized ultrafast preparation of stable superhydrophobic and superamphiphobic coatings on substrates of different materials and complex-shaped by the combination of phase separation and dip-coating.Firstly,silica was modified with fluorosilane to reduce the surface energy,and then combined with different kinds of polymer adhesives by solvent-controlled phase separation.Finally,superhydrophobic and superamphiphobic coatings were prepared by the one-step dip-coating method.The surface structure and chemical composition of the coatings were regulated by controlling the content of adhesives and the degree of phase separation,and then the superhydrophobic and superamphiphobic coatings with excellent performance were prepared.The main research contents and results are as follows:The suspension containing the superhydrophobic modified Si O₂（FD-silica）and the poly（styrene-co-isoprene）（PSI）adhesive was prepared by a non-solvent（butyl acetate-ethanol）induced phase separation process.Then,the FD-silica/PSI superhydrophobic coatings were successfully prepared by one-step dip-coating in the suspension.The coatings exhibit excellent superhydrophobicity towards water（water contact angle=165.7°,water sliding angle=1.2°）and various frequently used fluids.The coatings also show superior puncture resistance and high stability.Meanwhile,the coatings have excellent mechanical stability,chemical stability and thermal stability.For example,the coatings still have superhydrophobicity after being impacted by 50 k Pa water pressure for 30 min;after being soaked for a period of time in acid,alkali,salt and other strongly oxidizing solution;or after heat treatment at400°C and long-term UV radiation.The superhydrophobic coatings can be applied in the fields of anti-corrosion and anti-icing,etc.The strategy can make the substrate of various materials and complex shapes superhydrophobic,and also has many advantages such as simple,rapid,large-scale preparation and low cost,which is significantly superior to the traditional methods.Based on the above study,the FD-silica/500s superamphiphobic coatings were prepared by using ethyl acetate as the solvent instead of butyl acetate and polyurethane 500s as the binder to further regulate the surface structure and chemical composition of the coatings.The coatings not only have excellent static superamphiphobic properties,but also have excellent dynamic superamphiphobic properties.The superamphiphobic properties can be maintained after impacting of oil droplets from a height of 35 cm.The coatings have excellent mechanical stability,chemical stability,thermal stability and anti-UV aging stability.For example,the coatings are still superamphiphobic after 90 times of tape peeling,immersion in different corrosive solutions,heat treatment at 400°C,20 cycles in the simulated light and rain forest experiment.In addition,the coatings also have good anti-icing performance.In the outdoor dark condition,the freezing time of water droplets on the coating surface was significantly prolonged.This study provides a new approach to solve the bottlenecks of superhydrophobic and superamphiphobic coatings such as complex preparation method,poor stability and limitations in practical applications.This study also explores the application of the superhydrophobic and superamphiphobic coatings in anti-icing and anti-corrosion.This study provide a new idea for the preparation and industrial applications of superhydrophobic and superamphiphobic coatings.