STIR 2 (IMAGE) Rice University Caption A pristine stir bar made of ferromagnetic metal with a PTFE, or Teflon, coating. Rice University chemists discovered the inert bars, which are commonly used to mix chemicals, cause unwanted results during Billups-Birch reactions with carbon and other nanotubes. Credit Brandon Martin/Rice University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.