Fabrication of superhydrophobic paper surface via wax mixture coating

• The paper surface was rendered superhydrophobic via the phase separation of green-based waxes.
• The key steps consisted of emulsifying, coating and annealing, which could be readily accomplished.
• The entire process for superhydrophobic modification was free of organic solvent and fluorochemicals.
• The wax coating layer showed good transparency and mechanical durability.

Nowadays researches endeavour to prepare superhydrophobic paper surface without using fluorderivates which are harmful to both environments and humans. This research aimed at building microstructure using green-based waxes to prepare superhydrophobic paper surface. There were two main processes. First, wax mixture (beeswax/carnauba wax) was emulsified and coated on paper surface. Then the coated paper was annealed at various temperatures. The surface energy of wax mixture increased slightly as the weight ratio of carnauba wax increased. The further heat treatment rendered wax coated paper from hydrophobic or superhydrophobic to “Lotus” state, because submicrometer structure was produced on the base of micrometer spherical wax particles. The wax coating layer also showed good transparency and stability properties.