The utility of carbon nanomaterials is highly dependent upon the precision upon which they can be assembled and functionalized. New methods enable high impact applications in sensing, mechanical, membrane, and energy storage/conversion. Approaches to the formation of functional assemblies of carbon nanotubes will be described that involved the non-covalent immobilization of the materials into functional assemblies. In a non-covalent method, no direct chemical bonds are made to the carbon nanotubes, thereby leaving their electronic properties intact. New covalent connections to the graphene surfaces (sidewalls) of the carbon nanotubes will also be discussed and how these materials can serve to modify their electronic properties for devices as well as hard wire functional assemblies to the carbon nanotubes to provide interactions with chemicals (sensors) or electrocatalysis (energy conversion). Many of these methods are also applicable to the functionalization of graphite to create new forms of graphene. We will also show how high purity graphene can be produced in using new scalable electrochemical methods.