Slow dynamics in a model of the cellulose network

TL;DR

This paper models cellulose microfibril networks with crosslinks, revealing slow, glassy dynamics due to frustration, which can be modulated by altering interaction strengths, providing insights into plant cell wall behavior.

Contribution

The study introduces a numerical model of cellulose networks with microfibrils and xyloglucan crosslinks, demonstrating slow glassy dynamics and the impact of interaction strength on microfibril reorientation.

Findings

Network exhibits logarithmic structural relaxation.

Glassy dynamics caused by frustration from xyloglucan crosslinks.

Weakening interactions enhances microfibril reorientation.

Abstract

We present numerical simulations of a model of cellulose consisting of long stiff rods, representing cellulose microfibrils, connected by stretchable crosslinks, representing xyloglucan molecules, hydrogen bonded to the microfibrils. Within a broad range of temperature the competing interactions in the resulting network give rise to a slow glassy dynamics. In particular, the structural relaxation described by orientational correlation functions shows a logarithmic time dependence. The glassy dynamics is found to be due to the frustration introduced by the network of xyloglucan molecules. Weakening of interactions between rod and xyloglucan molecules results in a more marked reorientation of cellulose microfibrils, suggesting a possible mechanism to modify the dynamics of the plant cell wall.