Corrosive environments tolerant, ductile and self-healing hydrogel for highly efficient oil/water separation

Constructing high-performance materials that combine high separation efficiency, corrosive environments tolerance and self-healing ability are highly attractive for the next generation oil/water separation materials, but it is still a grand challenge. Here, we report a supramolecular hydrogel network of acrylamide and acrylic acid copolymers (P (AM-co-AA)) and chitosan (CS), sequentially cross-linked by amino-functionalized silica (APTES-SiO2) nanoparticles. The as-prepared APTES-SiO2/P (AM-co-AA)/CS composite hydrogels demonstrate outstanding ductility up to 1360% elongation, and good self-healing ability, combined with excellent under-water superoleophobicity with an oil contact angle above 164°. Most importantly, the underwater superoleophobic properties can be well maintained in various extremely harsh environments, such as acid, alkali and salt solution, providing great potential for oil/water separation in these corrosive environments. Indeed, the hydrogel-coated mesh displays oil/water selectivity above 98.7% at higher water flux.