Drexel University engineers
continue to drive research into the use of carbon nanotubes, straw-like
structures that are more than 1,000 times thinner than a single human hair.
Their most recent development uses the tiny tubes to separate liquids within a
solution.

The researchers have shown
that individual carbon nanotubes can act as a separation channel that would
force two differing molecules to separate as easily as oil and water. For
example, the molecules that comprise two chemically distinct liquids will
interact differently with the walls of the nanotube as the liquids flow through
it. This will cause one of the liquids to drain through the nanoscale straw
faster than the other, thus forcing a separation between the two liquids.

This technology could prove
useful in a number of applications, including forensic studies with very small
sample sizes and studying molecules extracted from individual cells. Forensic
experts would be able to analyze trace evidence, even down to a single cell or
invisible stains.

“We believe that this
research will lead to development of tools for analysis on single living cells
and push the limits of analytical chemistry to even smaller scales and to
single organelle columns,” said Yury Gogotsi, director of the A.J. Drexel Nanotechnology Institute.

Gogotsi and Gary Friedman, director of the Drexel
Plasma Medicine Lab and a professor of electrical and computer engineering,
were the lead researchers on a study about applications of nanotubes for
cellular chromatography that was published in Scientific Reports. The
research was funded by a grant from W.M. Keck Foundation and the National
Science Foundation’s National Interdisciplinary Research Teams program.

The carbon nanotubes used
in this study measure as small as 70 nm in outer diameter and are currently the
smallest chromatography columns ever made. The carbon nanotube columns are
mechanically robust and are able to withstand repeated bending and compression.
These characteristics are vital for applications at the cellular level, as the
tiny tubes’ durability allows them to penetrate cell membranes.

Continued nanotube research
by Drexel engineers will examine the development of electrochemical and optical
tools.

Source: Drexel University