An underwater pH-responsive superoleophobic surface with reversibly switchable oil-adhesion

An underwater pH-responsive superoleophobic surface successfully demonstrated a reversible switch of oil-adhesion on a nanostructured poly(acrylic acid) (PAA) surface by changing the environmental pH values. At low pH, intramolecular hydrogen bonding of PAA is formed, and results in high oil-adhesion. As for high pH, the oil droplets can easily roll off due to the intermolecular hydrogen bonding between PAA and surrounding water.