Fatang Liu, Funing Zhang, Xingjian Zhao, Yufei Lin, Jingxue Xu, Mingjian Luo, Huaiyuan Wang
Superhydrophilic/underwater superoleophobic surfaces can form continuous hydration layers, which are favored for various applications in the fields of antifouling, drag reduction, and oil–water separation. This study reported on cationic polymer superhydrophilic coatings prepared by chemical grafting, utilizing the Janus structure to increase the interaction between the coating and the substrate, and introducing self-healing properties into this coating to increase its durability. This process restored wettability after repairing damaged surfaces in air and also repaired structural breaks and restored surface wettability in harsh aqueous environments. In addition, the surface of the coating demonstrated smoothness and inhibited the adhesion of biological and organic molecules through electrostatic repulsion while further blocking the direct contact of pollutants with the substrate through hydration. This coating material demonstrated excellent antifouling, drag reduction, oil–water separation, scale inhibition, and antimicrobial properties, opening new avenues in the field of superhydrophilic/underwater superoleophobic surfaces.