Nicole

Hydrogen bonding has been employed as a powerful tool for developing multi-component assemblies such as supramolecular polymers. We have prepared graphene quantum dot (GQD)-organic hybrid compounds (GQD-2b-e) by introducing 3,4,5-tri(hexadecyloxy)benzyl groups (C16) and linear chains terminated with a 2-ureido-4-[1H]-pyrimidione (UPy) moiety onto the periphery of GQD-1. GQD-2b-e formed supramolecular assemblies through hydrogen bonding between the UPy units. GPC analysis showed that GQDs with high loadings of the UPy group formed larger assemblies, and this trend was confirmed by DOSY and viscosity measurements. AFM images showed the polymeric network structures of GQD-2e on mica with flat structures (approximately 1.1 nm in height), but no such structures were observed in GQD-2a, which only carries the C16 group. We found that GQD-2c and GQD-2d formed organogels in n-decanol, and the gelation properties can be altered by replacing the alkyl chains in the UPy group with ethylene glycol chains (GQD-3). These results demonstrate that GQD can be used as a platform for supramolecular polymers and organogelators by suitable chemical functionalization.