Water-soluble graphene sheets with large optical limiting response via non-covalent functionalization with polyacetylenes

Abstract

Water-soluble graphene sheet was prepared via chemical reduction of graphene oxide (GO) in the presence of polyacetylene bearing a quaternary ammonium pendant (Pac), with a relatively low feed ratio of 1/3 (Pac/GO, w/w). The non-covalent functionalization of graphene by Pac was mainly based on the electrostatic attraction and π–π interaction, the resultant material G–Pac showed good solubility in water with the concentration of 0.28 mg mL⁻¹. In virtue of the unique sp²-conjugated structure of graphene, it displayed a prominent optical limiting response, which could be potentially used in photonic or optoelectronic devices to protect human eyes or optical sensors from damage by intense laser irradiation.