Fig. 1.
Diffusion of PEGylated GNRs in semidilute 1-MDa PEO solutions (c ≥ c*). The translational diffusion coefficients of GNRs in PEO solutions compared with that of the GNRs in the solvent (water), DT/DT,solvent, is plotted as a function of the ratio of the GNR hydrodynamic radius, RH, to the PEO correlation length, ξ. For RH/ξ < 2.2, DT is reduced by less than one order of magnitude from that of the solvent, which we define as the “weakly constrained” regime. However, at sufficiently large polymer concentrations such that RH/ξ > 2.2, DT is reduced by a factor of ∼100 or more compared with that in the solvent (n = 10, average and SD). Cartoons illustrate the constraints upon GNR diffusion by polymer solutions below their overlap concentration c* (Left), above c* and in the weakly constrained regime (Center), and in the strongly constrained regime (Right). (Inset) Representative TEM of PEGylated GNRs.