Coalescence Model for Crumpled Globules Formed in Polymer Collapse

The rapid collapse of a polymer, due to external forces or changes in solvent, yields a long-lived “crumpled globule.” The conjectured fractal structure shaped by hierarchical collapse dynamics has proved difficult to establish, even with large simulations. To unravel this puzzle, we study a coarse-...

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Bibliographic Details
Main Authors: Bunin, Guy, Kardar, Mehran
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:English
Published: American Physical Society 2015
Online Access:http://hdl.handle.net/1721.1/98178
https://orcid.org/0000-0002-1112-5912
https://orcid.org/0000-0002-3074-4217
Description
Summary:The rapid collapse of a polymer, due to external forces or changes in solvent, yields a long-lived “crumpled globule.” The conjectured fractal structure shaped by hierarchical collapse dynamics has proved difficult to establish, even with large simulations. To unravel this puzzle, we study a coarse-grained model of in-falling spherical blobs that coalesce upon contact. Distances between pairs of monomers are assigned upon their initial coalescence, and do not “equilibrate” subsequently. Surprisingly, the model reproduces quantitatively the dependence of distance on segment length, suggesting that the slow approach to scaling is related to the wide distribution of blob sizes.