Application of 1D attapulgite as reservoir with benzotriazole for corrosion protection of carbon steel

The development of active systems to protect metal substrates against corrosion by using inhibitor loaded nanocontainers is a promising approach for many industrial applications. This study introduces attapulgite as a reservoir for loading a corrosion inhibitor (benzotriazole). As a key component, inhibitor loaded attapulgite was dispersed in a water-based epoxy coating to protect carbon steel. The release behavior of the encapsulated inhibitor from the attapulgite nanocontainers in response to pH variation was investigated using UV-visible spectroscopy. The corrosion properties of the composite coatings were explored by electrochemical impedance spectroscopy. The coating with inhibitor-loaded attapulgite demonstrated enhanced film barrier properties compared with blank coating. The scratched coating with inhibitor-loaded attapulgite showed increased corrosion resistance relative to that of the blank coating after immersion and hence exhibited an active corrosion protection. The coating's self-healing mechanism can be attributed to the passive film formation on the metal surface promoted by the inhibitor release from the nanocontainers. (C) 2017 Elsevier B.V. All rights reserved