Flexible paper-based composites with photothermal conversion and superhydrophobic properties

Biofiber is an extensive and renewable raw material, whose products meet the demands of constructing an environmental-friendly and resource-favorable society. As a typical biofiber assembly, paper inherits its characteristics and may lose its mechanical properties after prolonged contact with water, leading to a material failure. Here, we report an environment friendly waterproof composite by a simple surface treatment. This composite is creatively prepared via a formation of rough microstructures for ink micro-aggregates on the ink-brushed paper, of which this bio-inspired structure is beneficial to hydrophobic properties and light capture capability. Specifically, it possesses excellent hydrophobicity with a high contact angle over 150° and photothermal performance with a solar evaporation rate of 1.324 kg m −2  h −1 under 100 mW/cm 2 . In addition, it reveals superior waterproof and deicing performance, decreasing the icing adhesion time to 63 s under 100 mW/cm 2 . Additional advantages include durability, designability, and large-area production. In view of these excellent properties, this waterproof photothermal material holds a bright prospect in the fields of solar evaporation, deicing device, packaging, and so forth. Graphical abstract