Stainless Steel Screen Modified with a Self-Healing Hydrogel for Efficient Gravity-Driven Oil-Water Separation

摘要

Due to their low oil adhesion and selective oil-water separation, screens with superhydrophilicity and underwater superoleophobicity have attracted significant attention. However, oil-water separation materials with high efficiency and low cost are still urgently in demand. Here, inspired by natural marine mussels, we prepared a self-healing hydrogel-coated screen to achieve highly efficient oil-water separation. Polydopamine (PDA) was incorporated into polyacrylamide (PAM) and uniformly coated on a stainless steel screen to prepare a self-healing hydrogel-coated screen. The results showed that the PDA-PAM hydrogel coating firmly adhered to the stainless steel screen and exhibited superhydrophilicity and underwater superoleophobicity. Regarding the PDA-PAM hydrogel-modified screen with a coating time of 7 min, different types of oil-water mixtures could be driven by gravity to achieve a highly efficient oil-water separation rate of over 97%, and the water flux could reach 91,673 L m(-2) h(-1). After ten cycles, the separation efficiency did not decrease significantly, suggesting that the self-healing hydrogel-coated screen has excellent stability and recycling performance. This inexpensive novel filter screen with high efficiency has a wide range of potential application in the field of oil-water separation.