When people are building things such as decks or fences, they often use lumber that has been pressure-treated with preservatives. While this does indeed help the wood last longer, the chemicals will gradually leach out into the ground, harming organisms within it. Now, however, researchers have found a way of using nanotechnology to keep the preservatives in the wood.

The scientists, from Michigan Technological University, encapsulated tiny droplets of the fungicide tebuconazole within spherical nanoparticles. The spheres were chemically modified to work with the fungicide, and were made from either gelatin or chitosan – the latter material is derived from chitin, the main component of the exoskeleton of crustaceans, and has been used in everything from self-healing paint to a flu virus filter to a biocompatible transistor.

The nanoparticle-encapsulated fungicide was then applied to wood samples, using regular pressure treating techniques. Tests showed that the wood was just as insect- and rot-resistant as wood treated with conventional fungicide, yet 90% less leaching occurred. Further testing is now being performed in the warm, wet conditions of Hawaii.