Diversified separations of immiscible organic liquids by a modification of superwettable supramolecular framework composite on porous support

Abstract

Superwetting porous materials possessing wide applicability and responsiveness are becoming highly desired for the needs of the separation of immiscible liquid mixtures with less difference in surface tension during the treatment of wastes. In targeting this purpose, we propose a strategy to regulate the wettability of a sponge by coating a supramolecular framework (SF) bearing tunable wetting states under the assistance of polycaprolactone. This SF assembly-modified porous support demonstrates the under-liquid dual lyophobicity for polar liquids under nonpolar ones and for nonpolar liquids under polar ones via a simple in-situ adjustment of intermediate fluids. Depending on the capillary force of nanopores and amphiphilic components existing in the SF assembly, the switchable surface-modified sponge connecting to a pump quickly suction lyophilic organic liquids either located on the top or bottom phase despite touching the lyophobic liquids. Moreover, in-situ modulated filtrations to the emulsions comprising polar and nonpolar liquids are achieved with high efficiency (greater than 94.8 %) and flux (up to 9261.2 L m−2 h−1). Importantly, the suction and filtration separations are also available for organic liquid pairs with a high viscosity. The reversible interconversion between nonpolar and polar liquids is achieved and can be recycled several times with undiminished performance.