open access

https://hdl.handle.net/2115/79491

Effect of Structure Heterogeneity on Mechanical Performance of Physical Polyampholytes Hydrogels

英語

2019-10-08

American Chemical Society(ACS)

Macromolecules

52(19)

7369-7378

Recent studies reported a multiscale structure in tough and self-healing hydrogels containing physical associations. For example, a type of tough and self-healing hydrogel from charge-balanced polyampholytes (PA) has a mesoscale bicontinuous double network structure with structural length around 400 nm. This mesoscale network structure plays an essential role in the multistep rupture process, which leads to the high toughness of PA hydrogels. In this work, by using an osmotic stress method, we symmetrically studied how the relative strength of soft and hard networks and the strength of ionic bonds influence the property of PA gels. We found that increasing osmotic stress of the bath solution triggers the structure transition from bicontinuous double network structure to a homogeneous structure, which drives the concurrently opaque−transparent transition in optical property and viscoelastic−glassy transition in mechanical behavior. The gels around the structural transition point were found to possess both high toughness (fracture energy of 7200 J m−2) and high stiffness (Young’s modulus of 12.9 MPa), which is a synergy of soft network and hard network of the bicontinuous structure. Our work not only provides an approach to tune the structure and property of physical hydrogels through tuning physical association but also gives a demo to investigate their relationships, yet another step forward gives inspiration to design a new type of tough and self-healing materials around the structural transition point.

学術雑誌論文

Accepted Manuscript

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Macromolecules, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acs.macromol.9b01676.

0024-9297

1520-5835