Green modification of Siloxene using phytic acid-doped polyaniline and its application in water-based epoxy anti-corrosion coatings

Multidimensional nanocomposites integrate smart protection and physical barriers to prolong the service life of water-based self-healing coatings. Herein, polyaniline (PANI) and phytic acid (PA) were efficiently loaded onto siloxene sheets via a facile one-pot strategy to fabricate a nanocomposite with barrier and dual-release properties, which was introduced into water-based epoxy coating. As a modifier, PA greatly improved the dispersion of fillers and further enhanced the barrier performance and self-healing ability of the composite coating. Electrochemical impedance tests were adopted to evaluate the anticorrosion behavior of the as-prepared coating on low-carbon steel in 3.5% NaCl solution. The SPA-reinforced EP coating delivers outstanding long-term corrosion resistance, whose low-frequency impedance modulus (|Z| 0.01 Hz ) is three orders of magnitude higher than that of pure EP after 60 days of saltwater immersion. The superior performance originates from favorable filler-matrix interfacial compatibility, passivation film barrier effect and metal complexation. Salt spray tests also verify its reliable self-healing protection after coating damage. It is certain that this will provide an effective approach for improving the long-term application of water-based epoxy coatings in marine environments. Download: Download high-res image (138KB) Download: Download full-size image