Design,Preparation And Performance Of The Graphene Oxide Nanocomposite Hydrogel

Hydrogels consisting of a polymer network and water have been intensively investigated as smart materials for biomedical applications in tissue engineering and medical devices. In these applications, mechanical toughness and reliability are required to maintain the function of hydrogel under bearing compression, elongation, and shearing in tissues. For instance, the hydrogel used for artificial cartilage is desired to possess excellent mechanical performance to resist stretching, bending and abrasion during deformation. Several tough hydrogels, such as the double network gel, the nanocomposite gel, the slide-ring gel, have become promising candidate materials for the above demands. Approaches for enhancing their mechanical properties have been continuously and deeply explored however, the mechanical behavior of these tough hydrogels with defects should be investigated to ensure that they are sustainable and reliable during practical applications. Additionally, the self-healing capability of the hydrogels is also desired for applications.As a new type of 2D inorganic materials, graphene oxide (GO) has terrific electrical,optical and mechanical properties, while it’s oxygen-containing groups can easily form hydrogen bonds with polymer chains, making it an ideal synthetic materials. The introducing of GO in hydrogel matrix remarkably enhances mechanical properties. In this paper, we use graphene oxides in situ growing poly(N-isopropylacrylamide)nanogels as crosslinkers to synthesis high-mechanical hydrogels. The hydrogels tensile strain over 2500% and the tensile stress over 2 MPa with high fracture energy and notch-insensitive properties. The tensile strain reached 2000% and the tensile stress close to 1 MPa when the hydrogels have 1/4 notch. In addition, we also use GO in situ growing gold nanopariticles and form thiol-gold reversible bond withN,N’-Bis(acryloyl)cystamine as crosslinkers synthesis nanocomposite hydrogels. This kind of tough hydrogels has excellent mechanical properties as well as self-healing ability. The tensile strain of the self-healed hydrogels over 2000% and the tensile stress more than 1 MPa after the hydrogels are cut and irradiated for 2 min under near-infrared light. These indicate the GO hydrogels have excellent development prospects.