Design, Preparation And Performance Study Of Underwater Superoleophobic Hydrogel Coatin

The problems of oil pollution,pipeline clogging,and microbial adhesion caused by bad adsorption of various underwater equipment have seriously affected various production activities underwater and have become an urgent problem to be solved.In recent years,the research on the wettability of material surfaces and anti-adhesion properties has been increasing at home and abroad,and various strategies have been proposed based on surface wetting theory,such as super-sparse coatings,liquid-infused super-slip surfaces(SLIPS),liquid-like monolayer coatings,inorganic hydrophilic coatings and hydrogel coatings.Among them,hydrogel coating is a direct and economical method to coat the surface with hydrogel coating because of its excellent mechanical properties,underwater superhydrophobic properties,which can achieve a variety of materials and equipment surface anti-oil,lubrication and drag reduction,antibioadhesion and other properties.However,due to its own high hydration ability,hydrogel coating,when used underwater,will have problems such as partial detachment or rupture due to poor adhesion to the substrate and water absorption and swelling caused by the nature of the hydrophilic network structure of the gel itself,which seriously limits its application in practical situations.Therefore,it is still a challenging problem to design and prepare hydrogel coatings with both underwater superoleophobic properties and strong substrate adhesion.Epoxy resins(Eps)have been recognized as thermosetting materials of great importance and are usually applied to various anti-corrosion coatings,underwater coatings,and highperformance composites,etc.They play a key role in various industries such as transportation,construction,and aerospace due to their excellent mechanical and chemical stability,heat resistance,corrosion resistance,insulation,and strong bonding properties.This work utilizes the strong bonding performance of epoxy resin and introduces amine groups in the polyurethane system to design and prepare a polyurethane patch with interfacial activity,which is bonded to the substrate through the strategy of primer epoxy coating,where the epoxy layer provides strong bonding performance with the substrate,while the active polyurethane patch is affixed in the epoxy layer and a new chemical bond is formed between the interface to lock the polymer network structure and form a permeable layer.The patch does not require any chemical method pre-treatment of the substrate before use,only the prepared polymer patch is applied to the epoxy coated substrate,and then dried and cured,absorbing water soaked to obtain a hydrogel coating.After underwater swelling equilibrium,the polyurethane patch absorbs water to form a hydrogel coating to achieve super oleophobic properties,while being able to tightly bond to the epoxy layer to achieve strong adhesion with the substrate.The method can be applied to a large area,with simple process and outstanding performance,and has the prospect of realizing practical applications.Based on the strategy of epoxy primer,a series of amphoteric system hydrogels were designed and prepared to simultaneously achieve anti-bacterial adhesion,superoleophobicity and enhanced underwater adhesion with various substrates on the surface of amphoteric hydrogel coatings.The epoxy mid-coat was modified by ethyl isocyanate methacrylate to obtain an epoxy mid-coat covered with double bonds,and then the amphoteric system gel precursor was coated on the epoxy coating,and the polymer was "grown" on the epoxy mid-coat by interfacial chemical reactions initiated under the action of UV light,and then soaked in water and swollen to The hydrogel coating with ultra-high hydration ability gives the substrate surface super-oilophobicity and antibacterial properties.