Year: 2017
Type: article
Abstract: We study jamming in model freely rotating polymers as a function of chain length $N$ and bond angle ${\ensuremath{\theta}}_{0}$. The volume fraction at jamming ${\ensuremath{\phi}}_{J}({\ensuremath{\theta}}_{0})$ is minimal for rigid-rodlike chains (${\ensuremath{\theta}}_{0}=0$), and increases monotonically with increasing ${\ensuremath{\theta}}_{0}\ensuremath{\le}\ensuremath{\pi}/2$. In contrast to flexible polymers, marginally jammed states of freely rotating polymers are highly hypostatic, even when bond and angle constraints are accounted for. Large-aspect-ratio (small ${\ensuremath{\theta}}_{0}$) chains behave comparably to stiff fibers: resistance to large-scale bending plays a major role in their jamming phenomenology. Low-aspect-ratio (large ${\ensuremath{\theta}}_{0}$) chains behave more like flexible polymers, but still jam at much lower densities due to the presence of frozen-in three-body correlations corresponding to the fixed bond angles. Long-chain systems jam at lower $\ensuremath{\phi}$ and are more hypostatic at jamming than short-chain systems. Implications of these findings for polymer solidification are discussed.
Source: Physical Review Letters
Author: Robert S. Hoy
Institution: University of South Florida
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funder: National Science Foundation
OpenAlex ID: W2552272031