Lyophilic nonwettable surface based on an oil/water/air/solid four-phase system.

A lyophilic material’s surface, on which a liquid spreads with a contact angle (CA) of less than 90 ° , often causes problems such as fouling and fl uid transportation loss because of wetting by and high adhesion to the liquid. A lyophilic (CA < 90 ° ) yet nonwettable surface seems self-contradictory. Herein, we reveal that a lyophilic nonwettable surface is feasible in the oil/water/air/solid four-phase system. We design and prepare a re-entrant nanostructured glass surface by growing silicon nanofi laments, followed by fl uoro-modifi cation. [ 1 ] This surface shows good lyorepellence in air. When the surface is immersed in water, however, oil spreads on the surface but cannot wet it. This fi nding may throw light on multiphase wetting behavior and the application of lyorepellent surfaces in multiphase environments. Wetting is generally described by two basic models, i.e., the Wenzel [ 2 ] and Cassie models [ 3 ] in a triple-phase system. [ 4 ]