Paint that repairs its own scratches? Max Planck video on self-healing coatings

Scratches in paint are more than a cosmetic flaw: metal can start to rust at the damaged spot. This week the Max Planck Institute for Sustainable Materials in Düsseldorf released a video titled "Self-Healing Coatings: Can Paint Repair Its Own Scratches?"

The institute's corrosion group works on so-called self-healing protective coatings. According to the institute, today's active anti-corrosion coatings release their protective agents in an uncontrolled way, for example at high humidity even without corrosion – which shortens their service life and burdens the environment. Self-healing coatings are instead meant to store repair agents safely and release them only when corrosion actually starts.

To do this, tiny capsules are built into the coating, for instance into electrodeposited zinc or into organic paints. Release is triggered electrochemically, for example via capsules made of conducting polymers, or by a change in pH. The institute works with the Max Planck Institute for Polymer Research in Mainz; one aim is to supply enough active agent to heal larger defects as well.