Fig. 2. Swelling-strengthening behavior of swelling-strengthening hydrogels (SSHs) in vitro.
a Compressive modulus and b variation of compressive modulus versus swelling ratio. c Compressive stress and d variation of compressive stress at 90% strain versus swelling ratio. The strain rate was 5 mm/min, and the dimension of the cylindrical samples was 5 × 3 mm. All error bars represent the mean ± SD (n = 3 independent experiments). Significance was assessed using one-way ANOVA with Tukey’s multiple comparisons test, giving P values, ***P < 0.001, ****P < 0.0001.