0000000000909501

AUTHOR

Francis W. Starr

Polymer-specific effects of bulk relaxation and stringlike correlated motion in the dynamics of a supercooled polymer melt

We analyze dynamical heterogeneities in a simulated “bead-spring” model of a nonentangled, supercooled polymer melt. We explore the importance of chain connectivity on the spatially heterogeneous motion of the monomers. We find that when monomers move, they tend to follow each other in one-dimensional paths, forming strings as previously reported in atomic liquids and colloidal suspensions. The mean string length is largest at a time close to the peak time of the mean cluster size of mobile monomers. This maximum string length increases, roughly in an exponential fashion, on cooling toward the critical temperature TMCT of the mode-coupling theory, but generally remains small, although large…

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Publisher’s Note: “Polymer-specific effects of bulk relaxation and stringlike correlated motion in the dynamics of a supercooled polymer melt” [J. Chem. Phys. 119, 5290 (2003)]

a! Present address: Department of Physics, Wesleyan University, Middletown, CT 06459. b!Author to whom correspondence should be addressed. Electronic mail: baschnag@ics.u-strasbg.fr c!Author to whom correspondence should be addressed. Electronic mail: sglotzer@umich.edu FIG. 8. Temperature dependence of the ratio of ^sseg(tstr )& and ^s(tstr )&. tstr max is the peak time of ^sseg& and ^s& at different temperatures. TMCT 50.45. JOURNAL OF CHEMICAL PHYSICS VOLUME 120, NUMBER 14 8 APRIL 2004

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