Scaling behavior of fracture properties of tough adhesive hydrogels

TL;DR

This study investigates how the fracture properties of tough adhesive hydrogels change with swelling, revealing a scaling law linked to the shear modulus that informs future hydrogel design.

Contribution

It uncovers the correlation between polymer fraction and fracture energies in hydrogels, supported by scaling analysis and computational modeling.

Findings

Cohesion and adhesion energies scale similarly with polymer fraction.

Fracture properties are governed by the shear modulus scaling.

Results provide guidelines for designing tougher hydrogels.

Abstract

Tough adhesive hydrogels find broad applications in engineering and medicine. Such hydrogels feature high resistance against both cohesion and adhesion failure. The superior fracture properties may, however, deteriorate when the hydrogels swell upon exposure of water. The underlying correlation between the polymer fraction and fracture properties of tough adhesive hydrogels remains largely unexplored. Here we study how the cohesion and adhesion energies of a tough adhesive hydrogel evolve with the swelling process. The results reveal a similar scaling law of the two quantities on the polymer fraction. Our scaling analysis and computational study reveal that it stems from the scaling of shear modulus. The study will promote the investigation of scaling of hydrogel fracture and provide development guidelines for new tough adhesive hydrogels.