Interface and Interphase in Polymer Nanocomposites with Bare and Core-Shell Gold Nanoparticles.

Area of Science:

• Materials Science
• Nanotechnology
• Computational Chemistry

Background:

• Polymer nanocomposites incorporating metal nanoparticles offer enhanced properties for bio-nanotechnology applications.
• Understanding the interfacial behavior between polymers and nanoparticles is crucial for designing advanced materials.

Purpose of the Study:

• To investigate the structural, conformational, and dynamical properties of polymer chains near gold nanoparticles using atomistic molecular dynamics simulations.
• To compare the behavior of polymer chains near bare and functionalized gold nanoparticles with bulk polymer behavior.
• To critically examine the concepts of interface and interphase in metal nanoparticle/polymer nanocomposites.

Main Methods:

• Atomistic molecular dynamics (MD) simulations were employed to study polyethylene (PE) chains interacting with gold (Au) nanoparticles.
• Bare Au NPs were constructed using ab-initio calculations and Wulff construction; functionalized NPs were modeled considering chemical adsorption.
• Polymer-nanoparticle interactions were parameterized using Density Functional Theory (DFT) calculations.

Main Results:

• Polymer density profiles, bond order parameters, and segmental/terminal dynamics were computed to characterize interfacial effects.
• The study found that the extent of the interface/interphase is property-dependent.
• Anchored polymer chains significantly alter the density profile and dynamics of nearby polymer chains.

Conclusions:

• The interface and interphase in polymer/gold nanoparticle nanocomposites exhibit complex, property-specific characteristics.
• Functionalization of gold nanoparticles and polymer chain anchoring influence interfacial properties and polymer dynamics.
• Atomistic MD simulations provide valuable insights into the nanoscale behavior of polymer nanocomposites.