Environment friendly superhydrophobic and transparent surface coating via layer-by-layer self-assembly for antifogging of optical lenses.

The fogging of the optical lenses seriously affects the life quality and safety, which is due to the gathering of the humid air into liquid droplets on the solid surface because of the temperature change. Superhydrophobic coating modification is an effective way to repel the water from surface. However, due to the specific application requirements, the transparency of optical lenses after coating modification is still the challenge for the application of such superhydrophobic coatings. In this work, a superhydrophobic and transparent surface coating was fabricated by the layer-by-layer self-assembly followed with fluorination. After poly(sodium 4-styrenesulfonate) and poly(allylamine hydrochloride) (PAH) multilayer precoating was generated on the surface, the different bilayers of SiO nanoparticles in different particle sizes and PAH multilayers were fabricated. The obtained polyelectrolytes-nanoparticle multilayers were fluorinated by a fluorinating agent. Such polyelectrolytes-nanoparticle multilayered coating renders obvious micro-nano composite structure, showing excellent superhydrophilicity, whereas such coating modified eyeglasses keeps excellent light transparency. The results of antifogging and defogging test also proved that the eyeglass modified with this coating had good antifogging and defogging performance. Therefore, such polyelectrolytes-nanoparticle multilayered coating with excellent superhydrophobic and transparent properties might provide a feasible approach for the practical antifogging application of optical lenses.