It's certainly a hassle when a car gets a big paint-scratch, but smaller scratches in its clear coat are much more common and still unsightly. A new corn-based transparent finish could help, as its scratches heal up when subjected to heat.
Developed by scientists at Germany's Leibniz Institute for New Materials, working with colleagues at Saarland University, the "Nanomer" lacquer incorporates ring-shaped molecules known as cyclodextrins.
Derived from corn starch, these are threaded like pearls onto long-chain polymer molecules. The cyclodextrins are then able to move freely along the length of those chains, but are kept from falling off the ends by large "stopper" molecules. All of the cyclodextrin-loaded long-chain polymer molecules are in turn cross-linked to one another, via a chemical reaction.
The result is a flexible, elastic polymer network. When that network is heated, the cyclodextrin rings slide along their chains, filling in any gaps that may have been caused by scratches.
Initially, the healing time sat at several hours. By adding ingredients such as inorganic nanoparticles, however, the scientists were able to shorten that to just one minute at a temperature of 100 ºC (212 ºF). They are now working on scaling up the production process, and are looking for industry partners to help commercialize the Nanomer technology.
Interested parties can check out a live demo of the self-healing lacquer, at the Hannover Messe trade show in April.
