Superhydrophobic/superoleophilic starch-based cryogels coated by silylated porous starch/Fe3O4 hybrid micro/nanoparticles for removing discrete oil patches from water

Development of novel superhydrophobic adsorbents to remove oil spills that threaten aquatic ecosystems is necessary. To realize smart superhydrophobic starch-based adsorbents and reduce the use of metal-oxide particles in magnetic superhydrophobic coating , silylated porous starch/Fe 3 O 4 hybrid micro/nanoparticles (SPF) were developed, and then innovatively introduced onto the surface of starch cryogel (SPF@SC) by spray-coating technique. The surface chemical composition and hierarchical micro/nanostructures, which contribute to the high water contact angle (>152.0°) and low sliding angle (<9.0°) of the as-prepared material, were characterized in detail. SPF@SC possessed excellent water repellent, self-cleaning, and anti-fouling properties, as well as good mechanical and chemical durability. SPF@SC can be remotely propelled by a magnet on the surface of water to flexibly clean discrete oil patches. Moreover, an internal/external collaborative oil absorption behavior was also found unexpectedly in the absorbent. This study provides a strategy for the design of novel adsorbents that could be applied to tackle discrete oil contaminates over the ocean.