Super-durable, non-fluorinated superhydrophobic free-standing items

Abstract

Although superhydrophobic coatings are commercially available, their weak mechanical durability hinders their large-scale applications such as for structural materials. Here a general press-in-mold method is reported to rapidly fabricate super-robust and non-fluorinated superhydrophobic free-standing items, through dispersing hydrophobic SiO₂ nanoparticles in a series of polymers. The mechanical and chemical strength can be greatly improved by increasing the fabrication pressure, and the materials are found to retain superhydrophobicity after a knife/file scratch test, a liquid nitrogen test, severe sand/water impacts, acidic/alkali corrosion and 2000 cm sandpaper abrasion. These materials achieved better abrasion resistance than commercial superhydrophobic coatings and a higher retention ratio after abrasion tests and hardness than those of bricks. Radar diagrams were used to generalize the results of the mechanical and chemical tests to compare the material performances of SiO₂/polymer blocks with those of bricks and commercial superhydrophobic coatings. The SiO₂/polymer blocks achieved much better overall performance. This simple method has great potential for making either small domestic items or structural materials with robust superhydrophobicity.