Electrospinning Janus Nanofibrous Membrane for Unidirectional Liquid Penetration and Its Applications

J anus membrane with opposite wettability on its two sides has witnessed an explosion of interest in the field of liquid spontaneous and directional transport for their promising prospect. The advances in fabrication technology and natural bionics have brought remarkable progress for the development of Janus materials. Among the exciting progress, the micro/nanofabrication technique of electrospinning shows advantages in constructing thin porous fibrous membrane materials with controllable surface wettability and hierarchical structures. Here, a brief review of bioinspired Janus membrane for unidirectional liquid penetration fabricated by electrospinning is presented, and the underlying scientific mechanism is discussed with an emphasis on the materials design involving asymmetric surface wettability and micro-topology structure. An overview of recent emerging applications is also reviewed, with special attentions to liquid separation, water collection, distillation, and smart textile, etc. As researchers keep to develop more efficient strategies on designing new Janus membrane with higher performances, it has become increasingly important to understand the mechanism of liquid moving dynamics at the asymmetric interface in order to better recognize the scientific limitations currently hindering the field development. At last, the challenges currently faced and possible strategies on developing new Janus membranes for optimization and engineering in the future are proposed.