Transparent surface with reversibly switchable wettability between superhydrophobicity and superhydrophilicity.

In the present work, we have successfully fabricated a polyelectrolyte-tethered transparent surface on which superhydrophobicity and superhydrophilicity can be reversibly switched via counterion exchange between the chloride ion (Cl(-)) and perfluorooctanoate ion (PFO(-)). The stable superhydrophobic state can be obtained only when a certain extent of fluorine is chemically incorporated into the grafted polyelectrolyte. The counterion exchange does not have any influence on the transmittance of the transparent surface. The superhydrophobicity and superhydrophilicity can be reversibly switched on the surface for many cycles without any apparent damage to the wetting properties. Additionally, the transparent surface can be applied to prepare smart glass displays to hide and convey information by patterning the counterion distribution on the surface on the basis of the different antifogging properties between superphydrophobic and superhydrophilic surfaces.