Tuesday, August 05, 2008

US Patent 7407640 - Defunctionalizing CNT composites with radiation


Often in order to effectively incorporate carbon nanotubes in a polymer matrix the nanotubes need to be functionalized with another molecule for uniform distribution in the polymer and to avoid clumping of the nanotubes. However, this functionalization can also detract from the optimum properties offered by nanotubes such as high thermal and electrical conductivity. This patent from Rice University teaches defunctionalization of carbon nanotubes after incorporation in the polymer matrix to avoid the loss of the optimum properties of the nanotubes. Claim 1 reads:

1. A method comprising the steps of:

a) dispersing functionalized carbon nanotubes in a solvent to form a dispersion of functionalized carbon nanotubes;

b) incorporating the dispersion of functionalized carbon nanotubes into a polymer host matrix to form a functionalized carbon nanotube-polymer composite; and

c) modifying the functionalized carbon nanotube-polymer composite with radiation, wherein the modifying comprises defunctionalizing of the functionalized carbon nanotubes and wherein the radiation is selected from the group consisting of protons, neutrons, alpha particles, heavy ions, cosmic radiation, solar wind, and combinations thereof.