fig2

Figure 2. (A) Photos of the striped hydrogel sample: (i and ii) sustaining large elongation and (iii) lifting a 200 g weight. All optical photographs were taken by the authors using personal mobile devices; (B) Typical tensile stress - strain curves and (C) the corresponding elastic modulus and toughness of PAM, PAM/SIW, PAM/COS, and PAM/COS@SIW hydrogels. Data are presented as mean values ± SD, n = 3 independent samples; (D) Tensile loading - unloading curves and (E) the corresponding dissipated energies and hysteresis ratios of the PAM/COS@SIW hydrogel at different strains; (F) Ten consecutive loading - unloading cycles and (G) the corresponding dissipated energies and maximum stresses of the PAM/COS@SIW hydrogel at a maximum strain of 600%; (H) Compression curves of the PAM/COS@SIW hydrogel at different strains; (I) Ten consecutive cyclic compression curves of the PAM/COS@SIW hydrogel at a compressive strain of 80%. PAM: Polyacrylamide; SIW: silicotungstic acid; COS: chitosan oligosaccharide; SD: standard deviation.