Fluorinated SiO2 nanoparticle size effect on traffic marking coatings

Under rainwater and mechanical abrasion, traffic markings undergo rapid visibility loss, raising critical transportation safety concerns. From a materials engineering standpoint, fluorinated SiO₂ nanoparticles (F-SiO₂) of five sizes (20 nm to 1000 nm) were incorporated into a marking coating. Standardized Taber abrasion testing was employed to investigate the particle-size dependence of wetting, saline corrosion resistance, and wear-induced hydrophobic evolution. The 50 nm particles created an optimal micro/nano morphology that sustained a Cassie–Baxter state (water contact angle > 150°, sliding angle < 5°). During Taber abrasion, preferential matrix wear progressively exposed the embedded particles; the well-matched micro/nano scales of the 50 nm filler enabled synergistic regeneration of surface chemistry and topography. After 200 cycles, the coating maintained a contact angle > 150° and a sliding angle < 5°, with mass loss reduced by over 80 % relative to a pure coating and virtually no decline in superhydrophobicity. In contrast, 20 nm particles were easily encapsulated and lacked long-term wear resistance, while particles ≥ 100 nm induced an irreversible Wenzel transition. This particle-size window therefore combines wear-induced hydrophobic regeneration with saline corrosion resistance, providing a basis for long-life, maintenance-free self-cleaning traffic markings.