Fabrication And Performance Study Of Superhydrophobic Self-cleaning Surfaces

Superhydrophobic surfaces have broad market prospects and application potential in the industrial,medical,and daily life fields due to their excellent self-cleaning and other functions.By studying the superhydrophobic function of natural biological surfaces,it has been found that their hydrophobicity is related to surface microstructures and surface free energy.Therefore,the main approach to preparing superhydrophobic surfaces is to introduce microstructures into low surface energy substrates or modify rough substrates.However,the current techniques for preparing superhydrophobic surfaces have drawbacks such as high cost,long processing time,and the use of fluorinated modifiers.In addition,the stability of current superhydrophobic surfaces is poor,which seriously limits their large-scale industrial production and practical application.Therefore,the current challenge for researchers is to develop a fast,low-cost,and large-area method for preparing stable superhydrophobic self-cleaning surfaces.This thesis starts from the practical application of superhydrophobic self-cleaning surfaces and uses efficient and simple methods and low-cost,fluorine-free and harmless hydrophobic materials to prepare three types of superhydrophobic self-cleaning surfaces with good stability.Firstly,for the problems of easy wipe damage and poor durability of the ordinary superhydrophobic carbon soot surface deposited directly.In this thesis,a stable superhydrophobic self-cleaning surface was prepared on a brass substrate by first etching a rough shape on the substrate using an electrochemical etching method,then brushing a PDMS mixture with a 5:1 mass ratio of prepolymer and curing agent as an intermediate bonding layer,and finally depositing hydrophobic carbon soot particles directly in the middle of the candle flame.The raw materials used in the preparation process,such as the candle,are common and readily available in daily life,and the preparation steps are simple and easy to follow.Test results show that the surface exhibits excellent self-cleaning properties against solid and liquid contaminants,and excellent durability against simulated rain erosion,sandpaper abrasion,and immersion in acid and alkaline solutions.Secondly,a zinc layer with a low coefficient of friction and good wear resistance was first coated on the stainless steel substrate surface using electrodeposition,which not only improved the mechanical wear resistance of the surface,but also achieved the rough microstructure required for a superhydrophobic surface.Subsequently,the substrate was hydrophobically modified using stearic acid,which is acid and alkali resistant,easy to repair and environmentally friendly and fluorine-free,thus in preparing a galvanized/stearic acid superhydrophobic self-cleaning surface.The results show that the surface exhibits excellent self-cleaning properties against solid and liquid contaminants commonly found in life,and it retains its superhydrophobicity after the surface is damaged by testing methods such as tape peeling,sandpaper abrasion,and corrosive liquid attack.At the end of this thesis,a nanosecond laser device was used to process suitable microstructure patterns on the surface of the stainless steel substrate,taking advantage of laser processing with controlled structure and stability and efficiency.Then the surface was hydrophobically modified using myristic acid,which is low-cost,environmentally friendly and non-toxic and stable,to obtain a superhydrophobic self-cleaning surface.The relevant test results show that the surface has excellent water repellency,outstanding self-cleaning properties and good stability.