Interface-initiated polymerization enables one-pot synthesis of hydrophilic and oleophobic foams through emulsion templating

Unlike oil-absorbing hydrophobic and oleophilic materials, porous materials that simultaneously display hydrophilicity and oleophobicity in air are rare, but they are unique in selectively removing water from bulk oil. Preparation of such porous materials is limited to the surface coating of raw porous materials, which faces problems such as pore clogging and uneven coating on inner surfaces. Herein, a one-pot approach to fabricating hydrophilic and oleophobic foams from oil-in-water high internal phase emulsions through a facile interface-initiated polymerization strategy is reported. The foams have interconnected macroporous structure. They can absorb water drops quickly while repelling oils in air. Such foams may find applications not only in oil–water separation (e.g., fuel purification), but also for efficient removal of contaminants (e.g., dyes) from oil-containing wastewater, where the oleophobicity helps foams to eliminate the oil fouling issue.