Superhydrophilic and Underwater Superoleophobic Poly(propylene) Nonwoven Coated with TiO₂ by Atomic Layer Deposition

Abstract To develop an effective and convenient solution for underwater repelling oil and cleaning up oily water, TiO₂ nano‐coating is deposited on the surface of poly(propylene) nonwoven (PPN) by atomic layer deposition (ALD). There is no evident change in the morphologies comparing ALD‐modified PPN with PPN except for thickness. For oils of different densities, such as 1,2‐dichloroethane, methylene chloride, chloroform, carbon tetrachloride, n‐hexane, and petroleum ether, the underwater oil contact angle and underwater oil sliding angle of ALD‐modified PPN range from 152.25° to 156.19° and 5.63° to 8.80°, respectively, exhibiting superior superhydrophilicity and underwater superoleophobicity. Notably, ALD‐modified PPN shows a high chemical stability in different solutions, such as acid, alkali, salt, and polar solvent, which even can slightly improve the underwater superoleophobicity of TiO₂ nano‐coating. The excellent underwater anti‐oil property, self‐cleaning property, robust chemical resistance, and easily scaled‐up preparation process of TiO₂‐coated PPN suggest great potential for practical applications in the energy, environmental protection, marine anti‐fouling, and microflow control fields.