Wrinkling of Random and Regular Semiflexible Polymer Networks

TL;DR

This study explores how semiflexible polymer networks, both random and regular, develop wrinkles under shear, revealing universal scaling laws and the impact on elastic properties, with implications for material characterization.

Contribution

It provides new insights into the wrinkling behavior of semiflexible polymer networks, highlighting the universal scaling of critical shear angle and the microstructure independence of wrinkle wavelength.

Findings

Wrinkling occurs above a small critical shear angle that scales with bending modulus.

Random networks show hysteresis and metastable wrinkled states.

Wrinkles reduce elastic energy and influence elastic behavior.

Abstract

We investigate wrinkling of two-dimensional random and triangular semiflexible polymer networks under shear. Both types of semiflexible networks exhibit wrinkling above a small critical shear angle, which scales with an exponent of the bending modulus between 1.9 and 2.0. Random networks exhibit hysteresis at the wrinkling threshold. Wrinkling lowers the total elastic energy by up to 20% and strongly affects the elastic properties of all semiflexible networks such as the crossover between bending and stretching dominated behavior. In random networks, we also find evidence for metastable wrinkled configurations. While the disordered microstructure of random networks affects the scaling behavior of wrinkle amplitudes, it has little effect on wrinkle wavelength. Therefore, wrinkles represent a robust, microstructure-independent assay of shear strain or elastic properties.