Preparation Of Kaolin/Polymer Composite Superamphiphobic Coating And Antifouling Durability Research

Generally,the surface with low surface tension liquid and solid surface contact angle greater than 150°and rolling angle less than 10°is called superamphiphobic surface,which has good repelling and cleaning ability to different water and oil liquids,and has great application potential in anti-fog,anti-corrosion,antiicing,antibacterial,self-cleaning and oil-water transportation.The construction of superamphiphobic materials requires two important factors: low surface free energy and micro/nano rough structure.In recent years,researchers have made remarkable progress through their efforts,but in the process of use,superamphiphobic materials are easily subjected to external stress and external corrosion damage and lose their unique properties,thus limiting their application in real life.Therefore,it is of great significance to prepare the durable superamphiphobic materials with good wear and corrosion resistance by means of low cost and simple process for its daily application.In this paper,the low-cost clay material kaolin is chosen as the matrix material and is treated with fluorosilane or fluorocarbon surfactant to modify and give it low surface energy.The modified product combines polymer materials to enhance physical durability and increases the combination of coatings and substrates.At the same time,antibacterial agents are added into the compound to give it antibacterial and antifouling properties.The contents and results of this dissertation are as follows.(1)Preparation and Durability of antifouling PFDTS-kaolin/PU superamphiphobic coatingIn order to obtain a coating material with a superamphiphobic effect,kaolin is used as the dressing matrix in this work.First,the kaolin was treated with 1H,1H,2H,2H-perfluorodecyltriethoxysilane(PFDTES)to obtain the fluorinated kaolin superamphiphobic powder(PFDTES-kaolin),and then the obtained powder was combined with polyether polyurethane(PU)in the way of physical blending to PFDTES-kaolin/PU.Finally,the coating was applied to the substrate and dried to obtain a superamphiphobic coating.The success of grafting fluorosilane onto kaolin surfaces was demonstrated by characterization.The resulting coatings have excellent hydrophobic and oleophobic properties,and under sandpaper wear and strong acid and alkali corrosion,the coatings remain in good superhydrophobic and superoleophobic condition.In addition,Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli)were used for bacterial anti-adhesion test,and sand and mud water were used for self-cleaning experiment.Experimental results show that the coating not only provides anti-bacterial adhesion,but also has a good anti-fouling effect.(2)Preparation and durability of heat-repairable Zn O/kaolin@fluoro POS/PDMS superamphiphobic antifouling coatingsIn order to further improve the durability of coating materials,the surface of kaolin was modified by sol-gel method using 1H,1H,2H,2H-perfluorodecyltriethoxylsilane(PFDTES)and ethyl silicate(TEOS)to obtain fluorinated oligosiloxane(fluoro POS)modified kaolin(kaolin@fluoro POS),and then Zn O was insitu formed on the surface of the powder by hydrothermal method,followed with drying to obtain superamphiphobic powder with repairable and antibacterial effects.Finally,a repairable antifouling superamphiphobic coating was obtained by mixing a polydimethylsiloxane(PDMS)solution with the superamphiphobic powder.The morphology and structure of the as-prepared material were examined.The results show that the coating has a repellent effect on soy sauce,milk,sunflower oil,coffee,vegetable oil,tea,glycerine,water and other liquids.Meanwhile,a friction test machine was used to test the friction durability of the coating.The results show good durability of the coating.When the coating has been corroded in acidic and alkaline solutions,and has lost its superamphiphobic properties,it is still capable of recovering its superamphiphobic character to a certain extent after high-temperature heating,that is,the coating has some repairability.This gives the coating good chemical stability and mechanical durability.At the same time,the introduction of Zn O gives the coating antibacterial properties and thus it has antibacterial properties.(3)Preparation and durability of photothermal self-healing FS-kaolin/Cu S-PDA/PDMS superamphiphobic antifouling coatingIn order to give the coating a better self-healing function after damage,and to obtain a relatively environmentally friendly superamphiphobic material for a durable superamphiphobic coating,in this section,fluorinated kaolin(FS-kaolin)was obtained by modifying kaolin with FS-61 fluorocarbons.The product was mixed with polydopamine(PDA)and Cu S nanoparticles to obtain FS-kaolin/Cu S-PDA powder,and PFDTES were added.Through the above multi-step reaction,FS-kaolin/Cu S-PDA/PDMS antifouling superamphiphobic coating with photothermal self-healing effect was finally obtained.Not only does the coating have good antifouling properties,but it also maintains photothermal self-healing and the photothermal effect can be repeated.Experimental results show that the coating retains a good superamphiphobility after wear in water flow,also maintains good tolerance in acid-based solutions and is well resistant to low surface tension liquids such as n-hexadecane.The Cu S and PDA nanoparticles give the coating a good antibacterial activity,give the coating a dual photothermal effect,and allow the coating to self-heal under optical conditions.In addition,fungal experiments showed that the coating had a certain antibacterial effect on not only bacteria but also penicillium,which greatly increased the durability of the coating.