When the rubber meets the road, it invariably leaves behind traces of the chemicals used to harden it during tyre manufacture. These chemicals, notably 2-(methylthio)-bezothiazole (MTBT), wash into waterways, where they can pose a health hazard if left untreated. The reactions used to break down MTBT just leave behind more waste — benign but useless.
Researchers in China report that they have found a way to not only neutralize MTBT, but also turn it into something valuable: an organic semiconductor. These are cheaper and more flexible than metallic semiconductors, and can be incorporated into items such as mobile-phone displays. Hui Huang at the University of the Chinese Academy of Sciences in Beijing and his colleagues applied a method that relies on a metal catalyst, acid and heat.
The team experimented with different recipes and temperatures to turn the MTBT into several different semiconductor compounds. One could be used to build a field-effect transistor, a key component of electronic devices. From another, the researchers created semiconductor nanoparticles, which can act as fluorescent dyes that allow scientists to image living cells in action.