Organic Media Superwettability: On-Demand Liquid Separation by Controlling Surface Chemistry

Superwettability
involving water affinity has demonstrated prominent
advantages in oil–water separation. However, superwetting surfaces
in nonpolar liquid–polar liquid systems are rarely explored
for the separation of organic liquids. In this work, a protocol of
elaborately controlling surface chemistry is presented to construct
dual superlyophobic surfaces for polar or nonpolar liquids in opposite
organic media. On two kinds of silver-roughened copper coatings, a
polar hydroxyl group is subtly integrated with nonpolar perfluoroalkyl
chain at the nanoscale. Prewetted by one organic liquid, the obtained
dual superlyophobic mesh can selectively intercept other immiscible
organic liquids, realizing high-efficiency on-demand separation. In
theory, the dual superlyophobic surfaces in organic media are strongly
dependent on their affinity toward polar liquids and the surface roughness.
The discovery may promote the development of organic liquid-related
interfacial materials.