LAUSR

The effect of graphene (G) and graphene oxide (GO) dispersions in a triblock copolymer, Kolliphor P407 (poloxamer-407), on the fluorescence of vitamin B2 (riboflavin) has been comparatively investigated. The quality of the dispersions was assessed by measuring the thickness of their flakes and visualizing their distribution within the copolymer and degree of exfoliation via scanning and transmission electron microscopies (SEM and TEM). The influence of G or GO and copolymer concentration on the fluorescence intensity was studied, and fluorescence quenching phenomena were observed; these become more effective with increasing G or GO content for Kolliphor concentrations equal to or above the CMC, the diminution in intensity being stronger for G dispersions, which is related to the different hydrophobicity of the nanomaterials, because these modify the distribution equilibrium of the vitamin between the solution and the Kolliphor micellar aggregates. Further, for a given G or GO concentration, the intensity ...