Conventional superhydrophobic surfaces are effective for liquids with low to medium viscosity but are ineffective against highly viscous liquids. The rapid formation of coatings with excellent universal antiadhesion and high mechanical strength remains a major challenge. This paper introduces a broadly applicable coating based on rational size-matching of multiscale particles and a chemical-heterogeneity design, maintaining super-repellency to liquids with viscosities ranging from 0 to 500,000 mPa s. The key to this design is a flexible diamino polyetheramine (D230) inserted between weakly polar micro/nano particles and poly(vinylidene fluoride) (PVDF), which transforms an intrinsically repulsive interface into a stable, cross-linked network. The optimized coating exhibits contact angles exceeding 150° and roll-off angles below 10° for most tested liquids, including low-viscosity liquids (water, cola, coffee), medium-viscosity liquids (honey, glycerol, stationery glue), and high-viscosity fluids (hydroxy-terminated polybutadiene (HTPB), mortar), while butyl rubber with a viscosity of 465,000 mPa s can also slide down on the surface. The coating withstands 550 Taber cycles, more than 1200 h UV exposure, over 100 immersion cycles in highly viscous liquids, and beyond 720 h soaking in acidic/alkaline media. A scalable spray process facilitates practical industrial deployment, enabling potential applications in precision casting, pipeline transport, mold release, and additive manufacturing.
Ke et al. (Fri,) studied this question.