Dual-Liquid-Diode Janus Mesh with Multisuperwettability for Unidirectional Oil–Water Transportation

Natural biological surfaces enable directional liquid transport and storage due to the specific characteristics and surface morphologies. Inspired by these natural mechanisms, it is of interest to have materials with an asymmetric surface energy or structures to achieve unidirectional liquid transportation. Herein, a dual-liquid-diode (DLD) Janus mesh with asymmetric superwettability on the two sides has been designed via electrospraying, with one side being superoleophobic/hydrophilic and the other side being superhydrophobic/oleophilic. The DLD Janus mesh was designed to enable unidirectional transportation of both oil and water in the opposite direction concurrently, in contrast to Janus membranes that were developed for a single liquid. Oil and water can unidirectionally pass through the DLD Janus mesh without an external energy supply in both air and liquid environments. This unique property enables the mesh with high flexibility in controllable multiphase liquid transportation scenarios. The DLD Janus mesh demonstrates promise for future applications in smart liquid separation, on-demand oil–water delivery, and fluid valve technologies.

天然生物表面凭借其独特的物理特性与表面形貌，可实现定向液体输运与存储。受此类自然机制启发，开发具备不对称表面能或不对称结构的材料以实现单向液体输运，成为当前研究热点。本文通过静电喷雾法，设计了一种双侧具备不对称超浸润性的双液体二极管（dual-liquid-diode, DLD）Janus网格，其一侧为超疏油/亲水表面，另一侧为超疏水/亲油表面。与仅针对单一液体开发的Janus膜不同，该DLD Janus网格可实现油与水同时沿相反方向进行单向输运。在空气与液体环境中，油与水均可在无需外部能量供给的前提下，单向通过该DLD Janus网格。这一独特性能使得该网格在可控多相液体输运场景中具备极高的应用灵活性。该DLD Janus网格在智能液体分离、按需油水输运以及流体阀技术等领域展现出良好的应用前景。