Method of coupling and aligning carbon nanotubes in a nonwoven sheet and aligned sheet formed therefrom

Abstract

Carbon nanotubes are coupled and aligned in a non-woven sheet as measured by failure strain by drawing the sheet with a coupling agent such as triphenylmethane and preferable a liquid diluent such as chlorosulfonic acid or sulfuric acid. The formed non-woven sheet has a full width at half maximum as determined by wide angle X-ray diffraction of not greater than 20°.

What is claimed is: 
     
         1 . A method aligning carbon nanotubes in a non-woven sheet comprising the steps of:
 (a) providing a non-woven sheet of carbon nanotubes with nanotubes which are not aligned,   (b) contacting the non-woven sheet of carbon nanotubes with a coupling agent to achieve mechanical coupling between adjacent carbon nanotubes.   (c) drawing the non-woven sheet of carbon nanotubes with mechanically coupled carbon nanotubes to impart:
 (i) stress among carbon nanotubes and 
 (ii) alignment of individual nanotubes in a direction the non-woven sheet is drawn. 
   
     
     
         2 . The method of  claim 1  wherein a diluent liquid is employed in step (b). 
     
     
         3 . The method of  claim 2  wherein the diluent liquid is chlorosulfonic acid, sulfuric acid, methanesulfonic acid or a solution of ammonium persulfate in sulfuric acid. 
     
     
         4 . A non-woven sheet containing aligned carbon nanotubes, said sheet having a full width at half maximum as determined by wide angle X-ray diffraction of not less than 20° 
     
     
         5 . A non-woven sheet containing aligned carbon nanotubes, said sheet having a full width at half maximum as determined by wide angle X-ray diffraction of not less than 10° 
     
     
         6 . A non-woven sheet containing aligned carbon nanotubes, said sheet having a full width at half maximum as determined by wide angle X-ray diffraction of not less than 5°