Dynamic heterogeneity in fully miscible blends of polystyrene with oligostyrene
Vagelis A. Harmandaris, Kurt Kremer, and George Floudas
Accepted
Binary blends of polystyrene with oligostyrene are perfectly miscible (��=0) yet dynamically heterogeneous. This is evidenced by independent probing of the dipole relaxation perpendicular to the backbone by dielectric spectroscopy and molecular dynamics. The selfconcentration model with a single intra-molecular length scale qualitatively describes the slower segmental dynamics. A quantitative comparison based on MD however, requires a composition-dependent length scale. The pertinent dynamic length scale that best describes the slow segmental dynamics in miscible blends relates to both intra- and inter-molecular contributions.