Collective Intermolecular Motions Dominate the Picosecond Dynamics of Short Polymer Chains

摘要: Neutron scattering and extensive molecular dynamics simulations of an all atom ${\mathrm{C}}_{100}{\mathrm{H}}_{202}$ system were performed to address the short-time leading center-of-mass self-diffusion. The simulated are in excellent agreement with resolution resolved time-of-flight quasielastic neutron scattering. anomalous subdiffusive motion could be modeled by explicitly accounting for viscoelastic hydrodynamic interactions. A model-free analysis local reorientations backbone revealed three relaxation processes: While two relaxations characterize bond rotation global reorientation, third component on intermediate times attributed transient flowlike motions atoms different molecules. existence these collective motions, which clearly visualized this Letter, strongly contribute chain liquids.