Improvement of self-healing property of graphene oxide-based cross-linked hydrogels using iron(iii) ion

Abstract

Hydrogels with the combination of high mechanical toughness and good self-healing properties are highly desired for the development of artificial tissues used in biomedical engineering. The lack of degree of physical and chemical crosslinking density in a same matrix, limited its real-time applications. In this study, we demonstrated a new strategy to fabricate tough and self-healable hydrogel nanocomposites using Fe3+ metal ions as a filler material in the graphene oxide-based (GOBC) cross-linked polyacrylic acid (PAA) hydrogel. The PAA-GOBC prepared by the incorporation of GOBC crosslinker resulted in hydrogels with high mechanical toughness, but weak self-healing efficiency. To improve the self-healing efficiency, Fe3+ metal ions were incorporated in PAA-GOBC hydrogels. PAA-GOBC-Fe3+ demonstrated a significant improvement in self-healing efficiency as well as mechanical toughness. The mechanical properties and self-healing behavior of the prepared PAA-GOBC-Fe3+ hydrogels were analyzed at different compositions of GOBC and Fe3+ to compare their effect in the hydrogel composites. The mechanism of the interaction for the improved properties was explored by comparing the stress-strain behavior of the prepared hydrogels. The improved properties are related to the multifunctional cross-linking ability of GOBC in the hydrogel matrices. This facile method to fabricate hydrogels with good mechanical toughness and self-healable properties is expected to widen the practical applications of such soft materials in biomedical engineering.