Graphene oxide/polyacrylamide/carboxymethyl cellulose sodium nanocomposite hydrogel with enhanced mechanical strength: preparation, characterization and the swelling behavior

Abstract

A ternary graphene oxide (GO)/polyacrylamide (PAM)/carboxymethyl cellulose sodium (CMC) nanocomposite hydrogel with improved compressive strength was fabricated through free radical polymerization of AM in the presence of GO and CMC in an aqueous system, followed by ionically crosslinking CMC by aluminium ions. The compressive strength of the ternary hydrogel was dramatically enhanced as compared to that of the pristine PAM/CMC hydrogels with the incorporation of an appropriate amount of 1.6 wt% GO sheets. Fourier transform infrared spectroscopy (FT-IR) characterization demonstrated that hydrogen bonds formed between the oxygen-containing groups of the GO sheets and the N–H bond of PAM. This strong interaction resulted in the dense structure of the nanocomposite hydrogel and improved mechanical strength. Moreover, the GO content significantly influenced the swelling behaviors of the composite hydrogels. The kinetic study revealed that the swelling behaviors of nanocomposite hydrogels followed the pseudo-second-order dynamic equation. The strategy of combining GO reinforcement with a double network provides an advantageous protocol for the formation of a high-strength hydrogel, which may be used in bioengineering and drug delivery systems.