Self-healing coatings

Self-healing coatings developed by researchers at the University of Illinois can protect materials from the effects of environmental exposure.

Applications range from automotive paints and marine varnishes to the thick, rubbery coatings on patio furniture and park benches.

Paul Braun, a professor of materials science and engineering, said: 'Starting from our earlier work on self-healing materials, we have now created self-healing coatings that automatically repair themselves and prevent corrosion of the underlying substrate.'

To make the self-repairing coatings, the researchers first encapsulate a catalyst into spheres less than 100 microns in diameter.

They also encapsulate a healing agent into similarly sized microcapsules.

The microcapsules are then dispersed within the desired coating material and applied to the substrate.

Braun added: 'By encapsulating both the catalyst and the healing agent, we have created a dual capsule system that can be added to virtually any liquid coating material.'

When the coating is scratched, some of the capsules break open, spilling their contents into the damaged region.