mz8b00828_si_001.pdf (1.17 MB)
Threading of Unconcatenated Ring Polymers at High Concentrations: Double-Folded vs Time-Equilibrated Structures
journal contribution
posted on 2019-01-18, 21:29 authored by Jan Smrek, Kurt Kremer, Angelo RosaUnconcatenated
ring polymers in concentrated solutions and melt
are remarkably well described as double-folded conformations on randomly
branched primitive trees. This picture though contrasts recent evidence
for extensive intermingling between close-by rings in the form of
long-lived topological constraints or threadings. Here, we employ
the concept of ring minimal surface to quantify the extent of threadings
in polymer solutions of the double-folded rings vs rings in equilibrated
molecular dynamics computer simulations. Our results show that the
double-folded ring polymers are significantly less threaded compared
to their counterparts at equilibrium. Second, threadings form through
a slow process whose characteristic time-scale is of the same order
of magnitude as that of the diffusion of the rings in solution. These
findings are robust, being based on universal (model-independent)
observables as the average fraction of threaded length or the total
penetrations between close-by rings and the corresponding distribution
functions.