Mechanically viscoelastic nanoreinforced hybrid hydrogels composed of polyacrylamide, sodium carboxymethylcellulose, graphene oxide, and cellulose nanocrystals

Polyacrylamide-sodium carboxymethylcellulose (PMC) hybrid hydrogels reinforced with graphene oxide (GO) and/or cellulose nanocrystals (CNCs) were prepared via in situ free-radical polymerization. In this work, GO nanosheets were freshly synthesized by modified Hummer's method alongwith the aqueous suspension of CNCs by acid-hydrolysis. In addition, the effect of GO content (1.5 wt%) and CNCs (from 2.5 wt% to 10.0 wt%) was investigated in these quaternary hydrogels. The results showed good pseudo-plastic behavior, self-healing ability, mechanical performance, and shape-recovery behavior of the hybrid hydrogels reinforced with GO and CNCs content. PMC-GO1.5/CNCs10.0 hybrid hydrogel showed 110.5 kPa as compressive strength and stiffness value of 887.7 N/m (at 30% strain). Moreover, the synergistic effect of both GO and CNCs as nanoreinforcements in hydrogels provides a new point of view for the preparation of hybrid hydrogels having exceptional structural and mechanical properties. As-obtained hybrid hydrogels may have potential application in tissue engineering for tunable mechanical properties.