Bifunctional Core–Shell–Corona Particles for Amphiphobic Coatings

Bifunctional core–shell–corona particles that bore both fluorinated units and hydroxyl groups in the corona were synthesized. The core particles were prepared from monomer methyl methacrylate (MMA) and cross-linker ethylene glycol dimethacrylate (EGDMA). The shell was grown from MMA, EGDMA, and HEA-Cl [2-(2′-chloropropionato)ethyl acrylate] via seeded emulsion polymerization. The incorporated HEA-Cl groups initiated the atom-transfer radical polymerization of 2-hydroxyethyl acrylate (HEA) to produce a PHEA corona. Particles with both fluorinated units and hydroxyl groups in the corona were obtained after reacting ∼80% of the PHEA hydroxyl groups with perfluorononanoyl chloride. After casting trifluorotoluene dispersions of these particles onto a glass plate, the resultant coating was amphiphobic, possessing high contact angles for both water and diodomethane. For water, the advancing contact angle reached 165° and the advancing and receding angle difference (hysteresis) was small. Thus, the coating was superhydrophobic. More interestingly, the hydroxyl groups in the particle coronas could be used to bond with an epoxy glue, which adhered to glass substrate, to yield a “permanent” amphiphobic coating.