A high volume and low damage route to hydroxyl functionalization of carbon nanotubes using hard X-ray lithography

The efficient functionalization of large quantities of carbon nanotubes entangled in a non-woven fashion into bucky-papers has been demonstrated through exposure to hard X-rays generated by a synchrotron source. The X-ray beam solely functionalized the carbon nanotube outer walls and an optimum X-ray exposure energy between 1048 J cm−2 and 2096 J cm−2 has been found to achieve maximum hydroxyl group density. Sol–gel reaction between a commercial fluoro-silane and the hydroxyl-modified carbon nanotubes was successfully performed resulting in an even distribution of fluoride atoms on the carbon nanotube surface, opening the way for the mass production of functionalized carbon nanotubes.