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

An anticorrosion coating with precise controllable self-healing performance from active corrosion inhibition to passive barrier recovery is developed for designated corrosion regions. [Display omitted] •An anticorrosion coating with precise controllable self-healing performance is reported.•The precise control of healing actions even within a minimal area of 0.03 cm2 can be achieved within 60 s NIR irradiation.•The composite coating exhibits active anticorrosion behaviors when triggered by pH stimulus.•Intercalated GO yields universally distributed passive barrier to hinder the invasion of corrosion media. 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.