Effect of Gel Particle Content on Its Deformation Behavior in a Microgel-Reinforced Hydrogel

Microgel-reinforced (MR) hydrogels are tough gels composed of hard/brittle gel particles and a soft/extensible matrix network. The mechanical properties of MR gels are significantly influenced by the deformation of the gel particles because the hard/brittle gel particles act as a sacrificial network, which fractures preferentially and absorbs large mechanical energy. Although the gel particle content is a major factor in controlling the mechanical properties, the effect of gel particle content on the deformation behavior of the particles remained unclear. In this study, we clarify the effect of the gel particle content on its deformation and fracture behavior. We prepared MR gels with a wide range of gel particle contents and evaluated their mechanical properties and gel particle deformation behavior. We demonstrate that increasing the gel particle content enhanced the deformation and fracture efficiency of the gel particles, drastically increasing their mechanical strength.