Ultra-porous superamphiphilic aerogel enabled ultra-stable continuous separation of emulsion

Abstract

Superwetting materials are promising alternatives for remedying oil contamination in wastewater owing to their extreme surface wettability-guaranteed ultraselective rejection to oil/water. However, the selective rejection mechanism raised a critical challenge to accomplish a stable continuous separation due to the fouling problem caused by clogging of the rejected oil/water. Herein, we realized an ultra-stable continuous separation of a water-in-oil (W/O) emulsion by developing an ultra-porous (94.34% of porosity) superamphiphilic aerogel. The ultra-porous aerogel permitted the simultaneous high-flux permeation of both water and oil phases for its superamphiphilicity, which selectively captured water phase inside the ultra-porous voids that served as large-capacity reservoirs via its underoil superhydrophilicity. This unusual “non-selective permeation and selective capture” separation mechanism completely avoided the formation of water barrier. When applied in column separation, the ultra-porous superamphiphilic aerogel realized an ultra-stable continuous separation of W/O emulsion.