US Patent 7666939 - Stable CNT dispersion in polymer

http://www.freepatentsonline.com/7666939.html

A variety of techniques have been employed to uniformly disperse carbon nanotubes in polymers. However, over days or weeks it has been observed that phase separation of the nanotubes and polymer occurs indicating thermodynamic instability. This patent from NASA teaches the use of electron donating and electron accepting functional groups to increase long term dispersion. Claim 1 reads:

1. A dispersion of carbon nanotubes in a polymer matrix, which dispersion exhibits long term stability, the dispersion comprising:

carbon nanotubes, which have been introduced into a polymer matrix and separated therein;

the polymer matrix having moieties therein which are capable of a donor-acceptor complexation with the carbon nanotubes.