Particles comprising stacked graphene layers

Abstract

According to the invention there is a particle including a plurality of stacked sub-structures, each sub-structure including a stack of graphene layers, in which the separation between successive stacked sub-structures is greater than the separation between successive graphene layers in each sub-structure.

1 . A particle including a plurality of stacked sub-structures, each sub-structure including a stack of graphene layers, in which the separation between successive stacked sub-structures is greater than the separation between successive graphene layers in each sub-structure, wherein at least some of the graphene layers in the sub-structures; are surface modified by decoration with silicon, sulfur or selenium. 
     
     
         2 . A particle according to  claim 1  in which the separation between successive stacked sub-structures is in the range 2 to 100 nm. 
     
     
         3 . A particle according to  claim 1  in which the sub-substructures each have a stack thickness which is in the range 0.7 to 15 nm. 
     
     
         4 . A particle according to  claim 1  in which each sub-structure includes a stack of between 2 and 12 graphene layers. 
     
     
         5 . A particle according to  claim 1  in which the sub-structures each have a stack thickness, and the stack thicknesses are less than the separation between successive stacked sub-structures. 
     
     
         6 . A particle according to  claim 1  having a thickness in the range 0.7 to 5 microns, preferably 1 to 5 microns. 
     
     
         7 . A particle according to  claim 1  having a width in the range of 1 to 15 microns. 
     
     
         8 . A particle according to  claim 1  in which the sub-structures have a net negative charge. 
     
     
         9 . A particle according to  claim 1  which has Stone-Wales defects. 
     
     
         10 . A particle according to  claim 1  which has a carbon content of greater than 80 wt. % 
     
     
         11 . 
     
     
         11 . A particle according to  claim 1  in which at least some of the graphene layers in the sub-structures are doped. 
     
     
         12 . A particle according to  claim 11  in which at least some of the graphene layers are doped with a dopant species, wherein the dopant species is one or more of N, B, S, Se and a halogen atom, preferably F. 
     
     
         13 . Particulate material including a plurality of particles according to  claim 1 . 
     
     
         14 . Particulate material according to  claim 13  having a surface area in the range 15 to 70 m 2  g −1 . 
     
     
         15 . Particulate material according to  claim 13  which is crystalline. 
     
     
         16 . Particulate material according to  claim 13  made by subjecting a starting material to a plasma treatment. 
     
     
         17 . A composite material including particulate material according to  claim 13  dispersed in a matrix material 
     
     
         18 . A composite material according to  claim 17  in which the matrix material is a polymer. 
     
     
         19 . A particle dispersion including particulate material according to  claim 13  dispersed in a liquid medium. 
     
     
         20 . An article including particulate material according to  claim 13 .