Superhydrophobic carbon nanotubes/epoxy nanocomposite coating by facile one-step spraying

A new superhydrophobic nanocomposite coating was prepared by combining the bisphenol A diglycidyl ether (BADGE) epoxy resin with unmodified multi-walled carbon nanotubes (MWCNTs). The mixture solutions were coated on the Q235 carbon steel surface through a facile and effective one-step spraying method. The highest water contact angle reached ~154° when 30% MWCNTs were added into the coating matrix. From the scanning electron microscopy (SEM) images, the superhydrophobic hierarchical microstructures were established via the agglomerated MWCNTs cured with epoxy resin. Furthermore, the as-prepared superhydrophobic nanocomposite coating with 30% MWCNTs showed excellent anti-icing property in the water-dripping and static freezing tests at the temperature of −10 °C. The superhydrophobic nanocomposite coating was endowed with an extraordinary mechanical durability, with the superhydrophobic state being retained even after 100 cycles in the tape-peeling test. From the electrochemical impedance spectroscopy (EIS) results, the low-frequency modulus first decreased due to the increasing conductivity of the coating surface, and then increased for the coating with 30% MWCNTs due to the air trapped in the superhydrophobic microstructure.