Universal unilateral electro-spinning/spraying strategy to construct water-unidirectional Janus membranes with well-tuned hierarchical micro/nanostructures.

Janus membranes (JMs) with hierarchical micro/nanostructures were constructed by unilaterally electro-spinning/spraying a hydrophobic polymer on various hydrophilic porous substrates for liquid manipulation/rectification. The membrane geometry and liquid transport behaviors can be delicately tuned. Our novel universal strategy can be extended to diverse hydrophobic porous substrates.