"Labyrinthine Structure" Anticorrosive Water-Based Composite Coatings

A new environmentally friendly modified graphene oxide/waterborne epoxy composite coating (W-EMGO) is reported. The composite coating, developed by introducing graphene oxide modified with [3-(2-aminoethyl) aminopropyl] trimethoxysilane (MGO) into waterborne epoxy, exhibited excellent corrosion resistance and slight harm of solvent-based coating to the environment. The MGO displayed perfect dispersion and corrosion resistance, which reduced the aggregation of graphene oxide (GO) due to the coupling of functional groups. After modification, the lamellar structure of GO remains unchanged, and the interlayer spacing was increased. Crosslinking with resin to form a "labyrinth structure" corrosion path in the coating. Furthermore, the conductivity of GO decreased after the insertion of functional groups. The results demonstrated that the composite with a 0.5 wt.% content of MGO presented remarkably improved corrosion resistance with a protection efficiency (PE) of 99.7%.