Preparation And Performance Study Of Environment-friendly Water-based Superhydrophobic Materials

In recent two decades,the research on superhydrophobic materials has advanced tremendously.Superhydrophobic materials have demonstrated excellent value in applications,such as self-cleaning,anti-icing,corrosion resistance,oil-water separation,pipeline transportation,liquid micro-controlled flow,and electronic devices.However,the preparation of superhydrophobic materials always uses fluorine-containing materials and volatile organic solvents(VOCs),which are a serious hazard to the ecological environment and human health.Moreover,there are problems,such as poor stability and high cost,in the preparation of superhydrophobic materials.All these challenges greatly hinder the large-scale application of superhydrophobic materials in real-life.In this thesis,with an aim at the problems faced by superhydrophobic materials and the trend of multi-functionalization,we adopt simple,low-cost,and environmentfriendly methods to prepare LDHs(Layered Double Hydroxide)multifunctional waterbased superhydrophobic materials,as follows:1.Superhydrophobic colorful pigments with color gradients were synthesized by a one-pot method under atmospheric pressure and water-based conditions.It was experimentally demonstrated that the water-soluble surfactant was grafted onto the surface of the Fe-based LDHs pigments with covalent bonding during the reaction,which achieved the synthesis and surface modification of the pigments simultaneously.In-situ mixing and self-matching of superhydrophobic pigments were accomplished by regulating the addition ratio of Ni and Fe ions.The pigments maintained their superrepellent properties in all types of complex chemical environments.Through conventional methods,such as spraying,painting,and spreading,superhydrophobic coatings,paintings,and superhydrophobic tapes with colorfulness could be constructed for multifunctional applications of superhydrophobic pigments.Moreover,the waste liquid generated in the reaction process could be recycled and reused for the preparation of superhydrophobic pigments,which basically achieved zero-waste emission in the whole process of pigment preparation.2.Based on the previous work,a fully water-based multifunctional superhydrophobic cotton fabric with colorfulness,oil-water separation,and flame retardancy was prepared by in situ growth using water as the reaction solvent.Experimental results demonstrated that the prepared superhydrophobic fabric had high hydrophobic performance,anti-fouling,and oil-water separation ability.Thanks to the abundant oxygen-containing functional groups such as hydroxyl and glucoside bonds on the cotton fiber surface,Ni Fe LDHs could grow vertically interconnected nanosheets on the fabric surface,which endowed the fabric with excellent hydrophobic properties.Meanwhile,the uniform distribution of Ni Fe LDHs nanosheets on the fabric surface made the fabric possess certain flame-retardant properties.Lastly,the prepared superhydrophobic fabrics exhibited excellent hydrophobic stability under various types of complex physicochemical environments.