Polyphenolic Chemistry-Enabled High-Performance Amphiphilic Size-Sieving Separation of Emulsions

Spreading is a critical step for emulsion separation. However, the spreading of emulsions on porous size-sieving materials is constrained by their small size-sieving pores formed on rough surface that frequently evolved into lyophobic air-solid-liquid interface to repel emulsions, resulting in poor separation flux. Herein, we demonstrated for the first time that endowing size-sieving materials with amphiphilicity was a promising and universal alternative to manipulate the spreading kinetics of emulsions for accomplishing high-flux separation. A variety of porous materials with varied chemical composition and high porosity, including metal-organic frameworks (ZIF-67, ZIF-8 and HKUST-1), activated carbon and γ-Al₂O₃, were endowed with amphiphilicity by polyphenolic chemistry-derived noncovalent amphiphilic decoration of polyphenols-iron ions complexes. The endowed amphiphilicity prevented the formation of lyophobic interface on the rough surface of the porous materials, which boosted the emulsion spreading kinetics by up to 11.8-fold, and a significant enhancement (492.3%) on separation flux was achieved by the amphiphilic size-sieving strategy. Our findings exploited a novel strategy for the big family of size-sieving materials to accomplish high-flux separation performances.