Corn-flower-like transparent, anti-moth protein and self-cleaning coatings for vehicle windshields

Abstract

Contamination of optical surfaces by complex viscoelastic foulants, such as bird droppings and moth proteins, poses severe risks to transport safety and device longevity. Traditional linear polymers preclude the synergy of high transparency, broad-spectrum omniphobicity, and mechanical robustness due to their uncontrollable segmental orientation. Herein, we engineer an anti-moth protein and self-cleaning coating featuring a “cornflower-like” array of perfluoroalkyl chains by integrating intrinsically low-surface-energy fluorinated molecules with hyperbranched polysiloxane backbones featuring multiple active sites. The resulting coating exhibits high optical transparency (91.8%), exceptional flexibility, and good durability. Benefiting from the hyperbranched architecture acting as a molecular spacer to facilitate the ordered arrangement of fluorine motifs and the self-enrichment of a dense –CF₃ shielding layer at the interface, the surface demonstrates ultralow surface energy (8.89 mN m⁻¹), low adhesion (SA = 5°), and superior self-cleaning/antifouling performance. It can effectively repel a higher-viscosity polar medium (η ≈ 1412 mPa s) as well as a lower-surface-tension non-polar medium (γ_L = 18.4 mN m⁻¹). Additionally, one month of ambient on-road tests confirm that the coated windshields maintain remarkable antifouling performance against recalcitrant stains (coverage area < 2%). This work provides a novel topological design rule for developing multifunctional protective interfaces in fields including transport, new energy, and buildings.