Structure and dynamics of large ring polymers

We report a comprehensive study on the molecular conformation and dynamics of very large poly(ethylene oxide) rings in melt: (i) for all rings, independent ring size, by small angle neutron scattering we observe crossover from strong Q-dependence at intermediate Q to Q?2 dependence higher Q. Constructing generic model including Gaussian statistics short distances more compact structures larger distances, find distance along Ne,0=45±2.5 monomers close entanglement linear counterpart. This finding is clear evidence predicted elementary loops building conformation. (ii) The radius gyration Rg(N) follows quantitatively result numerous simulations. However, other than claimed, mass fractal does occur around N?10Ne,0, but up N?44Ne,0, relation Rg(N)?N0.39 holds. self-similar was accessed pulsed field gradient-NMR spin echo spectroscopy: three dynamic regimes center diffusion starting with subdiffusive domain ?rcom2(t)??t?(0.4???0.65), second region ?rcom2(t)??t0.75 that (iii) finally, crosses over Fickian diffusion. internal scales below loop size well described Rouse motion. At scales, predictions scaling models preference loopy globule model. Finally, note key results were previously published form two letters [Kruteva et al., ACS Macro Lett. 9, 507–511 (2020) Kruteva Phys. Rev. 125, 238004 (2020)].