Preparation And Properties Of Superhydrophobic Materials Based On Copper Foam Foil

The superhydrophobic material is a biomimetic material inspired by the water-proof properties of the lotus leaf surface.When the contact angle of the solid surface is above 150° and the Sliding angle is below 10°,it can be called a superhydrophobic material.The material has broad application prospects in automobiles,ships,construction,and other industries;however,its own properties affect its further advancement into practical applications.On the one hand,the micro-nano structure is the main reason why the material has self-cleaning,drag reduction,and anti-icing properties.However,this structure will be easily damaged under certain external forces,such as rain erosion,friction,etc.,resulting in the loss of superhydrophobicity.On the other hand,laser etching,photolithography and other processes are required to obtain micro-nano structures in the past processes.These processes have disadvantages such as high price so that hard to develop into large-scale industries.Therefore,in this experiment,copper foam was selected as the matrix,and the micropores of this material can offer the microstructure necessary for the superhydrophobic surface,leaving out etching or other process.In order to further improve the wear resistance and corrosion resistance of superhydrophobic materials,four kinds of copper-foam-based superhydrophobic materials were developed in this experiment,and the hydrophobicity,wear resistance,corrosion resistance and stability were studied.The specific results are as follows:（1）The polytetrafluoroethylene（PTFE）and SiO₂ nanoparticles were coated on the copper foam substrate by the dip-pulling method to prepare the superhydrophobic material with three-layer structure.Then investigate the hydrophobicity,air environment stability,mechanical friction stability,drag reduction performance and Rust-proof properties were investigated.The Intrinsic CA of foam copper is 115°,improved to 140° after coating with PTFE,then improved to 154° after modified by SiO₂,meanwhile,SA is 6°.After being placed in the air environment for 270 days,CA dropped to 149°.the superhydrophobicity was lost when mechanical friction about 50 cm,CA was 147°,and SA exceeded 10°.Compared the running resistance with ordinary wooden boat models,with hydrophobic surfaces one has lower resistance.Experiments have proved the hydrophobic surface has certain anti-biosorption and anti-rust properties.（2）The dipping and pulling method were used to repeatedly coat SiO₂ and 1H,1H,2H,2H-perfluorodecyltriethoxysilane（PFDTES）to form a superhydrophobic material with a multi-layer stack structure.In order to further improve its mechanical friction stability and air environment stability,process optimization was carried out.The results show that with the increase of the stacked layers of SiO₂ and PFDTES,the hydrophobicity basically has a trend of increases first and then decreases,the maximum CA is 157°,and the minimum SA is 2.9°.As layers increases,the stability in the air environment improves.After placed 270 days,the minimum CA is decreased to 151°,and the maximum SA is increased to 7.7°.adding the stacked layers can improve the mechanical friction stability.The optimal result of this experiment is that CA is 152° when the friction distance is 100 cm,and SA is 7° when the friction distance is 60 cm.（3）Coating different proportions of SiO₂-SiC（A）nanoparticles and SiO₂-Fe₃O₄（B）nanoparticles respectively on the PTFE modified copper foam substrate,in order to improve the corrosion resistance,the effects of different nanoparticles and different mass ratios（MR）on the hydrophobicity and corrosion resistance were studied.The results show that when MR of A is 5:3,the CA is 157.9° and the SA is 1.3°.When MR of B is 1:1,CA is 156.2° and the SA is 7.1°.Research on its corrosion resistance shows that when MR of A is 3:5,the corrosion rate（CR）is the smallest and the corrosion resistance is the best;when MR is 5:3,CR is the largest and the corrosion resistance is the worst.When MR of B is 5:3,CR is the smallest and the corrosion resistance is the best,and when MR is 1:1,CR is the largest and the corrosion resistance is the worst.（4）A superhydrophobic material with a three-layer structure of copper foam / micron SiO₂ particles（A）-PTFE / hydrophobic nanoparticles（B）were prepared by dip-pulling method,and its hydrophobicity and corrosion resistance were investigated.The optimal formula and process are obtained through orthogonal tests.The results show that the mass of A is 0.2 g,the particle size of A is 0.5μm,and B is Fe₃O₄ particles with the best hydrophobicity,the contact angle is 157°,and the rolling angle is 4.5°.The mass of A is 0.4 g,the particle size of A is 10μm,and when B is Fe₃O₄ particles,the corrosion rate is the smallest and the corrosion resistance is the best.