Researchers from ETH and the Swiss Federal Laboratories for Materials Science and Technology (EMPA) have established a new measurement method to quantify the amount of free-standing and protruding multi-walled carbon nanotubes (MWCNTs). The results allow a prediction of the release of free-standing CNTs for the first time. In a worst-case scenario, up to 40 ppm of free-standing CNTs were released, representing a very low fraction of 0.004 wt%, but demonstrating that free-standing and protruding CNTs can be released in the scenario investigated. Read more