Figure 3.

Oscillatory time sweep experiments of the (a) single acylhydrazone-crosslinked hydrogels with different polymer concentrations, the molar ratios of ketone to hydrazine are fixed to 1.0; (b) single boronate ester-crosslinked hydrogels and double DCBs-crosslinked hydrogels (the PAD concentration is fixed to 10 wt%, the mass ratios of PAD to polyvinyl alcohol (PVA) are fixed to 0.5 and the molar ratios of ketone to hydrazine are fixed to 1.0); (c) storage modulus of the doubly DCBs-crosslinked hydrogels at different time during the gelation. All the experiments were performed at a frequency of 1.0 Hz and a strain of 1.0%.