NM08.03.16 : Spontaneous Exfoliation of Functionalized Graphene from Hyperstage-1 Graphite Intercalation Compounds and Its Applications

5:00 PM–7:00 PM Apr 3, 2018 (America - Denver)

PCC North, 300 Level, Exhibit Hall C-E

Intak Jeon1 Timothy Swager1

1, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States

Single layer graphene and few layer graphene have numerous scientific and technological breakthroughs for various nano-device applications. Manipulation of pristine graphene, however, is challenging since van der Waals energy stored in π–π stacked graphenes within a graphite crystal is relatively huge, which make graphene insoluble in water and organic solvents. Subsequently, extensive studies have been done on functionalization on the numerous defect sites and various oxygenated groups on graphene oxide (GO) or reduced graphene oxide (rGO). Due to the highly uncontrollable degraded carbon, GO/rGO has been limited into high performance materials. Thus, a synthetic method for graphene with controllable functional groups is extremely attractive. Here, we show a new method for breaking a wide area network of van der Waals coupling between graphene galleries. A new Hyperstage-1 graphite intercalation compound (GIC) is electrochemically activated and undergoes spontaneous exfoliation when reacted with diazonium ions to produce soluble graphenes with high functionalization densities of one pendant aromatic ring for every 12 graphene carbons. Significantly, the atomic force microscopy (AFM) profile reveals two distinct thicknesses of 2.4 and 4.4 nm. These heights correspond to two-sided functionalized single and double layer graphene structures and suggests that our method specifically produces dominantly single/double layer exfoliations. Critical to achieving high functionalization density is the Hyperstage-1 GIC state, are a weakening of the van der Waals coupling between adjacent graphene layers, and the ability of reactants to diffuse into the disordered intercalate phase between the layers. Functionalized graphene can be formed graphene composite through Meisenheimer complex formation. The formation of a Meisenheimer graphene complex has utility for creating new forms of functional graphenes.