Anticorrosion coating with near-infrared light triggered precisely controllable self-healing performances

Great attentions have been paid to anticorrosion coatings with self-healing performances to enhance its reliability and protection period, but massive challenges still remain for developing a coating with selectively triggered and accurately controllable self-healing behaviors. Herein, by integrating lamellar graphene oxide (GO) into a polycaprolactone (PCL) nanofiber loaded with 8-hydroxyquinoline (8HQ) corrosion inhibitors, a composite coating with precisely controllable self-healing capabilities is developed. The coating defects can be remotely and accurately repaired under near-infrared (NIR) light irradiation within a very short time. Notably, the precisely controllable defect recovery even within a minimal region of ∼0.03 cm² can be achieved, without causing pristine performance recession of irrelevant regions. The embedded GO can work both as efficient photothermal conversion materials, and yield "labyrinth effect" to enhance the passive barrier against corrosive media. Moreover, encapsulated corrosion inhibitors 8HQ can be rapidly released into acid/alkaline microregions in a corrosive-triggered manner, to form self-assembly protective layers and offer instant safeguarding for damaged sites. The integrated precise self-healing system enables extremely high corrosion inhibition efficiency exceeding 98.6 %. This work illustrates a feasible approach for combining remotely precise self-healing and active/passive enhanced passive barrier, presenting perspective potential in practical engineering anticorrosion applications or other controllable micro-reaction function surfaces.