One pot graphene-based nanocontainers as effective anticorrosion agents in epoxy-based coatings

A novel nanocontainer using graphene oxide nanoscrolls (GONS) as shell and benzotriazole (BTA) as core is proposed and embedded in epoxy coating for the corrosion protection of carbon steel. BTA/GONS nanocontainer is effectively fabricated by a modified shock-cooling approach. The hybrid material takes the specific shape of graphene oxide sheet spirally wrapped into scroll structure, acting as favorable physical barrier to afford encapsulation performance. A high uptake and storage of BTA in GONS is achieved, showing a loading capacity of 78.40%. The fantastically scrolled structure also provides an effective network to well control the BTA liberation during long-term immersion. The transport of BTA is diverse with pH values. The maximum release capacity of BTA occurs in neutral condition, larger than that in acid or alkaline environment. The liberation for up to 456 h exhibits the steady releasing characteristics of the containers. The corrosion inhibition performance of BTA/GNOS containers was mainly evaluated by electrochemical impedance spectroscopy. In comparison with, the reference epoxy coating, the one modified by BTA/GNOS nanocontainers demonstrate more excellent anticorrosion ability. The successful embedding and homogeneous distribution of BTA-loaded GNOS nanocontainers in epoxy film contributes to the improvement in the corrosion resistance of Q235 carbon steel and the self-healing performance of the coating.