How do carbon nanotubes work?

Small gas molecules are retained in their interiors by carbon nanotubes. These small gas molecules are selectively captured by the carbon nanotubes; this is possible due to their small size. The matter can be controlled on a nanometer scale, as a molecule can be absorbed inside another molecule. You can read about Nanotechnology in India – Origins, Uses, Developments in the given link.

Further readings:

1. Science & Technology Notes For UPSC – General Science Notes 
2. Science & Technology Questions in UPSC Mains GS-3