Multi-pores Janus paper with unidirectional liquid transport property toward information encryption/decryption

Janus membranes with unidirectional liquid transport property have tremendous applications in fields of functional fabrics, water harvesting, smart wound dressings and so on. Paper shows distinct advantages to other materials, such as hydrophilicity, low-cost, flexible and so on. However, there is still less attention on how to construct a Janus paper with unidirectional liquid transport capacity and its functional applications. Here, a multi-pores Janus paper with asymmetric wetting properties is developed through consecutive laser microdrilling, hydrophobic modification and air-plasma treatment. As a result, the prepared Janus paper can allow the water to transport from the hydrophobic side to the hydrophilic side, while it blocks the water to flow in the reverse direction. Meanwhile, it can also achieve antigravity unidirectional water transport. In addition, the mechanism for unidirectional liquid transport is investigated. Finally, as a proof-of-concept, the Janus paper is utilized for applications of information encryption/decryption.