Partially dehydrated zinc hydroxide sulfate nanoplates reinforced coating for corrosion protection

In this work, partially dehydrated zinc hydroxide sulfate nanoplates are synthesized by facile chemical bath deposition together with subsequent heat dehydration. The nanoplates exhibit well-defined hexagonal plate structure with smooth surface and no visible defects can be observed. Then, the corrosion protection performance of the nanoplates-embedded fluorocarbon coatings was investigated in 3.5 wt% NaCl aqueous solution. It turns out that the well dispersed nanoplates greatly enhance the protection ability of composite coatings. Once electrolyte permeates into the coating matrix and reaches the surfaces of nanoplates, the nanoplates can actively trap water molecules and ions (Cl− and Na+) therein through phase transition behavior, thus inhibiting the diffusion of electrolyte to the interface between coating and substrate. Meanwhile, the concomitant swelling of nanoplates blocks the diffusion of corrosive media, thus further enhancing the protection performance. The multi-functions of this material impart superior passive barrier and active barrier abilities to polymer coating.