Block copolymer nanofibers (BCNs) may be viewed as the macroscopic counterparts of polymer chains. While many techniques exit for the fractionation and characterization of polymer chains, these techniques generally fail when applied to BCNs. Reported in this paper is our preliminary success in fractionating polystyrene-block-poly(2-cinnamoyloxyethyl methacrylate)-block-poly(tert-butyl acrylate) or PS-b-PCEMA-b-PtBA nanofibers by centrifugation and in characterizing them by viscometry and dynamic light scattering (DLS).