Preparation Of Superhydrophobic Caotings With Excellent Mechanical And Chemical Stability By One-step Spraying

The role of superhydrophobic coatings in metal corrosion protection,oil spill treatment,water and dirt repellency cannot be overemphasised.However,conventional superhydrophobic coatings suffer from poor mechanical stability,single functionality and contain toxic components(elemental fluorine),which pose a challenge for the large-scale use of superhydrophobic coatings.Therefore,we propose a fluorine-free durable superhydrophobic coating constructed by one-step spraying based on self-designed resins with the introduction of micro/nanoparticles based on the lotus leaf effect.The organic-based superhydrophobic coating(W-GPAC coating)was prepared by combining a new silicone resin based on a dehydration condensation reaction centred on tin silicate and a ring-opening reaction between an amino group and an epoxy group with a biological wax.the W-GPAC coating exhibited excellent superhydrophobicity on glass substrates(CA=170.6°,SA=5.3°).Remarkably,the coating maintains its excellent superhydrophobicity in the water spray impact test(CA=160° after 500 water impacts),the linear wear test(CA=160° after 120 cm linear wear)and the acid and alkaline durability test(CA>165° after 600 minutes of immersion in an acidic or alkaline environment).In addition,the coating maintains excellent adhesion to a wide range of substrates,even when treated with freezing.A MOF-based superhydrophobic coating was constructed by combining a self-engineered small molecule resin using the sol-gel method with modified ZIF-8particles.Notably,the coating exhibits excellent superhydrophobicity(CA=169.05°,SA=3.7°),mechanical stability(CA>155° after 200 cm wear),high oil-water separation efficiency(up to 98.57% for oil-water mixtures)and satisfactory corrosion resistance(in an aqueous Na Cl solution with ω=3.5%,it can make Q235 steel(4orders of magnitude increase in the impedance modulus(0.01 Hz)of the base material).By introducing ZIF-8 nanoparticles modified with various organosilanes into a self-designed siloxane resin,a super-double hydrophobic coating with super-hydrophobicity and superoleophobicity was constructed.Notably,the coating exhibits excellent superhydrophobicity and superoleophobicity(CA>160°,SA<5°),excellent mechanical and chemical stability,and satisfactory self-cleaning properties.