Bioinspired Long-Lived SLIPS for Synergistic Drag Reduction, Corrosion Protection, and Marine Antifouling.

Biofouling, corrosion, and hydrodynamic drag degrade the marine infrastructure efficiency. Slippery liquid-infused porous surfaces (SLIPS) offer a promising antifouling strategy, yet are limited by lubricant depletion and lack of active chemical protection. Inspired by the jellyfish Cyanea nozakii (which combines a slippery surface and venom secretion), a nanocellulose-based SLIPS is developed with robust lubricant retention and pH-responsive controlled biocide release. Cellulose nanocrystal porous coatings embedded with chitosan-encapsulated Econea nanocapsules are infused with epoxy-anchored amino-silicone oil, forming a stable lubricating layer. This synergy ensures long-term lubricant preservation and prevents premature biocide leakage. The SLIPS exhibits up to 30% drag reduction, 95.7% corrosion inhibition in saline water, and strong resistance to bacterial and diatom adhesion. Marine field tests in the Bohai Sea showed over 90% biofouling suppression after 180 days. The design couples bioinspired surface lubrication with an on-demand chemical release to establish a scalable, sustainable paradigm for durable marine coatings. This versatile strategy enables long-term antifouling, corrosion protection, and hydrodynamic optimization in harsh marine environments.