Graphene oxide based crosslinker for simultaneous enhancement of mechanical toughness and self-healing capability of conventional hydrogels

Abstract

Introduction of a two-dimensional graphene oxide-based crosslinker simultaneously improve the mechanical and self-healing properties of hydrogels by offering an interesting combination of covalent and reversible hydrogen bonds to polymer backbones.

Self-Healing Hydrogels: Development, Biomedical Applications, and Challenges

“…Different self-healing hydrogels show different bonding dynamics. Figure 1 shows the bonding mechanism of functionalized graphene oxide crosslinked polyacrylamide hydrogel [ 16 ].…”

“…The enhancement of mechanical behavior often produces weak self-healing performance [ 16 ]. Assuring mechanical toughness and optimum self-healing performance is a tricky job in SHH development.…”

“…This may reduce the chances of the bond regeneration process and lead to a tough gel with weak healing ability. However, to introduce a mechanically tough but self-healable hydrogel, the proper combination of elastic and viscous properties or viscoelastic property is necessary [ 16 , 22 ]. Recently, Rumon et al [ 16 ] reported the viscoelastic property of their prepared material by the proper combination both of reversible and nonreversible chemical and physical active sides simultaneously.…”

“…These materials provide either dynamic reversible physical or reversible chemical bonds. However, dynamic reversible bonds, including hydrogen bond interactions, π-π stacking interactions, Van der Waals bonding, ionic bonds, etc., and the reversible covalent bonds have been continuously directed to design self-healable but tough hydrogels [ 16 , 24 ]. The biggest weakness of those strategies described is that they cannot address the root cause of the opposite relationship between mechanical toughness and self-healing ability.…”

“…The biggest weakness of those strategies described is that they cannot address the root cause of the opposite relationship between mechanical toughness and self-healing ability. Dahlquist criterion indicates that as the polymeric materials’ modulus increases, the self-healing ability is decreased, and high self-healing efficiency is difficult to obtain in large modulus hydrogels [ 16 , 18 , 25 ]. For example, Fan et al [ 26 ] reported a conventional hydrogel where tannic acid was used as a crosslinker to crosslink polyacrylamide and polyvinyl alcohol monomer [ 26 ].…”