Disentangling Self-Atomic Motions in Polyisobutylene by Molecular Dynamics Simulations.

ABSTRACT: We present fully atomistic molecular dynamics simulations on polyisobutylene (PIB) in a wide temperature range above the glass transition. The cell is validated by direct comparison of magnitudes computed from the simulation and measured by neutron scattering on protonated samples reported in previous works. Once the reliability of the simulation is assured, we exploit the information in the atomic trajectories to characterize the dynamics of the different kinds of atoms in PIB. All of them, including main-chain carbons, show a crossover from Gaussian to non-Gaussian behavior in the intermediate scattering function that can be described in terms of the anomalous jump diffusion model. The full characterization of the methyl-group hydrogen motions requires accounting for rotational motions.

SUBMITTER: Khairy Y 

PROVIDER: S-EPMC7927061 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature