Non-covalent interface engineering of multi-layer graphene cement composites using graphene oxide.

Area of Science:

• Materials Science
• Civil Engineering
• Nanotechnology

Background:

• Modern construction demands materials with rapid early strength development.
• Existing cementitious materials often face limitations in achieving sufficient early performance.
• Nanocomposites offer potential for significant improvements in cementitious material properties.

Purpose of the Study:

• To develop and investigate a novel multi-layer graphene/graphene oxide (MLGs/GO) nanocomposite system.
• To synergistically enhance the early performance of cement mortar.
• To elucidate the multiscale mechanism behind the observed performance improvements.

Main Methods:

• Experimental mixing and mechanical testing of cement mortar with MLGs/GO.
• Microstructural analysis to examine hydration products and pore structure.
• Molecular dynamics simulations to investigate interfacial interactions and stress transfer.

Main Results:

• An optimized mixture (1.0% MLGs +0.025% GO) achieved a 7-day compressive strength of 46.91 MPa, a 58% increase over MLGs alone.
• GO incorporation effectively dispersed MLGs and promoted the formation of key hydration products (CH, C-S-H, AFt).
• Molecular dynamics simulations confirmed GO enhances interfacial interactions and optimizes stress transfer between MLGs and the C-S-H matrix.

Conclusions:

• The MLGs/GO nanocomposite system offers a synergistic approach to significantly enhance early strength in cement mortar.
• GO plays a crucial role in MLG dispersion, hydration product formation, and microstructural refinement.
• The study provides a multiscale mechanism and practical insights for designing high-performance, early-strength cementitious materials.