An old, somewhat passé, trick used to purify protein samples
based on their affinity for water has found new fans at the National Institute
of Standards and Technology (NIST), where materials scientists are using it to
divvy up solutions of carbon nanotubes, separating the metallic nanotubes from
semiconductors. They say it's a fast, easy and cheap way to produce high-purity
samples of carbon nanotubes for use in nanoscale electronics and many other
applications.*