title: Molecular flexibility effects upon liquid dynamics.
abstract: Simulation results for the diffusive behavior of polymer chain/penetrant systems are analyzed. The attractive range and flexibility of simple chain molecules were varied in order to gauge the effect on dynamics. In all cases, the dimensionless diffusion coefficient, D*, is found to be a smooth, single-valued function of the packing fraction, eta. The functions D*(eta) are found to be power laws with exponents that are sensitive to both chain stiffness and particle type. For a specific system type, the D*'s for both penetrant and chain-center-of-mass extrapolate to zero at the same packing fraction, eta0. This limiting packing fraction is interpreted to be the location of the glass transition, and (eta0-eta), the distance to the glass transition.
authors.affiliation: Department of Materials and Metallurgical Engineering, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801, USA.
authors.forename: Julieanne V
authors.initials: JV
authors.lastname: Heffernan
authors.forename: Joanne
authors.initials: J
authors.lastname: Budzien
authors.forename: Aaron T
authors.initials: AT
authors.lastname: Wilson
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Baca
authors.forename: Victoria J
authors.initials: VJ
authors.lastname: Aston
authors.forename: Francisco
authors.initials: F
authors.lastname: Avila
authors.forename: John D
authors.initials: JD
authors.lastname: McCoy
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Adolf