Nano-Level Damage Characterization of Graphene/Polymer Cohesive Interface under Tensile Separation.

Area of Science:

• Materials Science
• Nanotechnology
• Computational Mechanics

Background:

• Graphene-reinforced polymer nanocomposites are crucial materials.
• Understanding graphene/polymer interface behavior is key to predicting material performance.
• Existing models may not accurately capture interface mechanics.

Purpose of the Study:

• To characterize the elastic-damage behavior of graphene/polymer interfaces.
• To develop and validate a hybrid molecular dynamic (MD) and finite element (FE) simulation approach.
• To compare exponential softening with bilinear softening models for interface damage.

Main Methods:

• Hybrid molecular dynamic (MD) and finite element (FE) simulations.
• Tensile separation simulations of graphene/polymer interfaces.
• Development and validation of a cohesive zone model (CZM).

Main Results:

• Graphene/epoxy interfaces exhibit an elastic-softening exponential regressive law.
• The cohesive zone model accurately predicts interface damage.
• Key interface parameters: normal stiffness (5 × 10^-8 aPa·nm^-1), tensile strength (9.75 × 10^-10 N·nm^-1), fracture energy (2.1 × 10^-10 N·nm^-1), and exponent α = 7.74.
• Bilinear softening models can introduce up to 55% error.

Conclusions:

• The exponential regressive law is essential for accurately modeling graphene/epoxy interface behavior.
• FE simulations with a validated CZM are adequate for predicting interface damage.
• Accurate interface modeling is critical for reliable nanocomposite design.