Large-area dual-scaled porous nitrocellulose (p-NC) membranes are fabricated by a facile, inexpensive and scalable perforating approach. These p-NC membranes show stable superhydrophilicity in air and underwater superoleophobicity. The p-NC membranes with intrinsic nanopores and array of microscale perforated pores could selectively and efficiently separate water from various oil/water mixtures with high efficiency (>99%) rapidly.

Because of the frequent oil spill accidents in marine environment, stable superoleophobic coatings under seawater are highly desired. Current underwater superoleophobic surfaces often suffer from mechanical damages and lose their superoleophobicity gradually. It remains a challenge to fabricate a stable and robust underwater superoleophobic film which can endure harsh conditions in practical application. Nacre is one of most extensively studied rigid biological materials. Inspired by the outstanding mechanical property of seashell nacre and those underwater superoleophobic surfaces from nature, we fabricated a polyelectrolyte/clay hybrid film via typical layer-by-layer (LBL) method based on building blocks with high surface energy. 'Bricks-and-mortar' structure of seashell nacre was conceptually replicated into the prepared film, which endows the obtained film with excellent mechanical property and great abrasion resistance. In addtion, the prepared film also exhibits stable underwater superoleophobicity, low oil adhesion, and outstanding environment durability in artificial seawater. We anticipate that this work will provide a new method to design underwater low-oil-adhesion film with excellent mechanical property and improved stability, which may advance the practical applications in marine antifouling and microfluidic devices.

Superoleophobicity under seawater: An ion-induced low-oil-adhesion film with underwater superoleophobicity is prepared by a typical layer-by-layer (LBL) method. Under an artificial marine environment with high ion-strength, the prepared polyelectrolytes/AuNPs hybrid film becomes rougher and possesses a higher water ratio, which in turn endows the film with superoleophobicity and low underwater oil adhesion. The as-prepared film shows excellent environmental stability in artificial seawater. This study provides a new strategy for controlling the self-cleaning property and accelerating the development of stable underwater superoleophobic films.

Inspired by selective wettability and hierarchical structure of papillae on lotus seeds, papilla-like magnetic particles were fabricated by thermal treatment of Fe microparticles. The papilla-like magnetic particles modified by lauric acid exhibited superhydrophobicity, superoleophilicity and great oil removing capability from water.