Poly(N-vinylcarbazole) chemically modified graphene oxide

Abstract

A new soluble donor-acceptor type poly(N-vinylcarbazole)-covalently functionalized graphene oxide (GO-PVK) has been synthesized by reaction of DDAT (S-1-dodecyl-S′-(α-α′-dimethyl-α″- aceticacid)trithioearbonate)-PVK with GO-toluene-2,4-diisoeynate. The incorporation of sufficient amount of PVK chains makes the modified GO nanosheets readily dispersible in organic solvents. The resulting material exhibits an enhanced solubility of 10 mg/mL in organic solvents. Covalent grafting of PVK onto the edge and surface of GO nanosheets did not change the car bazo le absorption in the ultraviolet region, but substantially reduced the absorption intensity of GO in the visible region. The intensity of the emission band of GO-PVK at 437 nm was a little bit quenched when compared with that of DDAT-PVK, suggesting intramolecular quenching from PVK to GO. Such intramolecular quenching process may involve energy or electron transfer between the excited singlet states of the PVK moiety and the GO moiety. The HOMO/LUMO values and the energy bandgap of GO-PVK experimentally estimated by the onset of the redox potentials are 5.60, 3.58, and 2.02 eV, respectively. © 2010 Wiley Periodicals, Inc.