Coalescence Model for Crumpled Globules Formed in Polymer Collapse

Area of Science:

• Polymer physics
• Soft matter science
• Computational modeling

Background:

• Rapid polymer collapse, driven by external forces or solvent changes, results in a long-lived "crumpled globule."
• The hypothesized fractal structure of crumpled globules, arising from hierarchical collapse dynamics, remains challenging to confirm, even with extensive simulations.

Purpose of the Study:

• To investigate the fractal structure of polymer crumpled globules.
• To understand the dynamics of hierarchical collapse in polymers.
• To identify the factors contributing to the slow approach to scaling in polymer collapse.

Main Methods:

• Development of a coarse-grained model simulating in-falling spherical polymer blobs.
• Modeling blob coalescence upon contact.
• Assigning distances between monomer pairs upon initial coalescence, without subsequent equilibration.

Main Results:

• The model quantitatively reproduces the observed dependence of distance on segment length.
• The model suggests a link between the wide distribution of blob sizes and the slow approach to scaling.
• The study provides insights into the formation and structure of crumpled polymer globules.

Conclusions:

• The developed coarse-grained model offers a viable approach to studying polymer collapse dynamics.
• The distribution of blob sizes is a key factor influencing the scaling behavior of crumpled polymers.
• Further research can utilize this model to explore polymer self-assembly and complex fluid behaviors.