Corrosion protection properties of Janus PTFE coatings in highly corrosive H2SO4 solutions

To improve the corrosion protection properties of polytetrafluoroethylene (PTFE) in highly corrosive H 2 SO 4 solutions, Janus PTFE coatings (PDA/PEI@PTFE) were constructed. The modified side is achieved by co-deposition of polydopamine (PDA) and polyethyleneimine (PEI) on the sodium naphthalene etched side of PTFE. It not only has a 5-fold increase in interfacial adhesion with substrates via chemical bonds, but also exhibits improved barrier properties due to the coverage of dense PDA/PEI film, with corresponding corrosion resistance increase by ~2–3 orders of magnitude. Meanwhile, the untreated side is hydrophobic pristine PTFE and has good self-cleaning properties and excellent resistance in concentrated H 2 SO 4 solutions. • Janus coatings (PDA/PEI@PTFE) were constructed by one side modification. • Almost 500% of adhesion enhancement was achieved. • The oxygen and water vapor transmission rates decrease by 18.0% and 33.3%. • An increase of coating resistance by ~2–3 orders of magnitude.