3D Interlayer Slidable Multilayer Nano-Graphene Oxide Acrylate Crosslinked Tough Hydrogel

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Improving hydrogel mechanical properties is crucial, often relying on nanocomposites as rigid nanofillers.
• The spatial structure contribution of nanocomposites to hydrogel mechanics remains underexplored.

Purpose of the Study:

• To develop a 3D nano chemical crosslinker, multilayer graphene oxide acrylate (mGOa), for enhanced hydrogel performance.
• To investigate mGOa's pressure-responsive crosslinking mechanism and its effect on mechanical properties.

Main Methods:

• Synthesized multilayer graphene oxide acrylate (mGOa) as a 3D nano chemical crosslinker.
• Incorporated mGOa into poly(2-hydroxyethyl methacrylate-co-acrylamide) hydrogels at a 2 mg/mL concentration.
• Evaluated mechanical properties (compressive strength, elastic modulus) via compression tests and compared with single-layer graphene oxide (sGOa) and small-molecule crosslinkers.

Main Results:

• mGOa-crosslinked hydrogels achieved a high mechanical strength of 14.1 ± 2.1 MPa at 90.6% strain, with a low initial elastic modulus (<0.03 MPa).
• Achieved significantly higher strength compared to sGOa (2.3 ± 0.8 MPa) and N,N'-methylene bisacrylamide (1.4 ± 0.4 MPa) crosslinked hydrogels.
• Demonstrated a responsive increase in modulus with strain, attributed to polymer chain synergism and mGOa interlayer sliding.

Conclusions:

• Multilayer graphene oxide acrylate (mGOa) functions as an effective pressure-responsive crosslinker, enhancing hydrogel toughness.
• Interlayer sliding of mGOa is identified as the key mechanism for mechanical strength improvement.
• Presents a novel approach for designing robust and high-performance hydrogels.