US Patent 7553471 - Manufacturing hydrophilic carbon nanotubes

http://www.freepatentsonline.com/7553471.html

This patent from Honda teaches a method of making carbon nanotubes dispersible in aqueous solutions without clumping which could be useful in forming carbon nanotube inks and paints. Claim 1 reads:

1. A method of manufacturing hydrophilic carbon nanotubes, comprising the steps of introducing hydrophilic functional group(s) into the surface of carbon nanotubes by irradiating the carbon nanotubes with an ultraviolet ray at an output ranging from 10 to 70 mW/cm2, wherein the hydrophilic functional group(s) is one or more groups selected from the group consisting of a hydroxyl group (—OH), a carbonyl group (—CO—), an aldehyde group (—CHO), a carboxyl group (—COOH), a nitro group (—NO2), and an amino group (—NH2).