Fig. 3.

Elasticity of silicified fibril hydrogels. (A) Frequency sweep of 1 wt % fibril + 1.2 wt % ${\mathrm{S}\mathrm{i}\mathrm{O}}_2$ hydrogel at a strain of 1%. (Inset) Self-supporting hydrogel. (B) Elasticity evolution of the silicified fibril hydrogels with increasing silica content, with protein monomer applied as controls. (C) Recovery property of the 1 wt % fibril + 1.2 wt % ${\mathrm{S}\mathrm{i}\mathrm{O}}_2$ hydrogel evaluated by the continuous steps of oscillatory strains: 1,000% and 1% strains are applied to break gel and measure recovery property, respectively. (D) Plotting the correlation of network elasticity and recovery rate. The recovery rate is defined as the ratio of recovered elasticity after the first destruction and heal cycle, $G_1$, and initial elasticity, $G_0$. Full line is for fibril-based hybrids; dashed line is for monomer-based hybrids. (E) Elasticity changes of 1 wt % fibril + 1.2 wt % ${\mathrm{S}\mathrm{i}\mathrm{O}}_2$ hydrogel at different damage–recovery cycles. (F) Theoretical prediction of the elasticity evolution as function of the probability $p$ of single bundling event at different $m$ values, where $m$ is the maximum number of virgin filaments in one bundled filament. The dashed line shows the $p$ range when $m$ = $\infty$, i.e., $p\in \left[\mathrm{0,0.5}\right]$.