Correlation between grafted nanoparticle-matrix polymer interface wettability and slip in polymer nanocomposites

Area of Science:

• Polymer Science
• Materials Science
• Computational Chemistry

Background:

• Controlling polymer nanocomposite (PNC) flow properties is crucial for their application potential.
• Understanding the interface dynamics between nanoparticles and polymer matrices is essential for material design.

Purpose of the Study:

• To investigate the slip behavior between rotating polymer-grafted nanoparticles and linear matrix chains using molecular dynamics simulations.
• To determine how interface wettability, graft length ratio (f), and graft density (Σ) influence slip (δ).

Main Methods:

• Molecular dynamics simulations were employed to model polymer-grafted nanoparticles in a polymer matrix.
• System parameters varied included interface wettability (f), graft-to-matrix chain length ratio, and graft chain density (Σ).
• Matrix chain penetration depth (λ) into the graft layer was analyzed.

Main Results:

• Significant tuning of interface slip (δ) was achieved by varying f and Σ.
• Both f and Σ influence interface wettability by altering matrix chain penetration depth (λ).
• Larger slip (δ) was observed at smaller f or Σ, decreasing as these parameters increased.

Conclusions:

• Interface slip (δ) in polymer nanocomposites can be effectively controlled by adjusting graft length ratio (f) and graft density (Σ).
• These parameters influence slip by modifying matrix chain penetration (λ) and interface wettability.
• The findings suggest that f and Σ are valuable tools for controlling the flow and mechanical properties of PNCs with grafted nanoparticles.