Superhydrophilic and underwater superoleophobic coatings on the basis of grafted polyelectrolytes on a textured aluminum surface

Water-loving compounds are usually used to prepare superhydrophilic and underwater superoleophobic surfaces. Hydrophilic polymers especially polyelectrolytes which contain the charged units in their structure is one of the perspective classes for the creation of materials with superhydrophilic properties. In this work, grafted polyelectrolytes based on quaternized N , N -dimethylaminoethyl methacrylate and sodium methacrylate were synthesized on the textured aluminum surface with an attached anchor layer (polyglycidyl methacrylate) and the initiator (2-bromo-2-methylpropionyl bromide) using surface-initiated atom transfer radical polymerization. The texturing of aluminum surface was performed using sequential etching in alkali and acid solutions. The lyophilic properties of grafted polyelectrolytes were studied by contact angle measurements using the “sessile drop” and “captive bubble” methods. The resulting coatings exhibit superhydrophilic properties due to quaternized ammonium and carboxyl charged groups in the grafted polyelectrolytes. Specifically, the coatings show complete wetting with water, stable aerophobicity and oleophobicity in aqueous media, and the demonstrated contact angles are greater than 170° for long contact times. It has been shown that grafting of polyelectrolytes prevents the sorption of nonpolar organic pollutants on the modified surface.