Integral equation theory for atactic polystyrene nanocomposite melts with a multi-site model

Area of Science:

• Polymer Science
• Materials Science
• Computational Chemistry

Background:

• Atactic polystyrene (aPS) is a widely used amorphous polymer.
• Understanding polymer melt structure and nanoparticle interactions is crucial for developing advanced nanocomposites.
• Existing models may not fully capture the complex behavior of polymer melts with dissolved nanoparticles.

Purpose of the Study:

• To develop and validate a multi-site chain model for polymer reference interaction site model (PRISM) theory.
• To investigate the structure and properties of atactic polystyrene (aPS) melt.
• To study the structural correlations and aggregation behavior of nanoparticles within aPS melt.

Main Methods:

• Incorporation of a multi-site chain model into the polymer reference interaction site model (PRISM) theory.
• Theoretical calculation of X-ray scattering intensities, solubility parameters, and intermolecular correlation functions.
• Investigation of distribution functions considering potential of mean force and depletion force for nanoparticle size effects.

Main Results:

• Theoretically calculated properties of aPS melts and nanocomposites show good agreement with molecular simulation and experimental data.
• Nanoparticle aggregation increases with the nanoparticle-site size ratio in the dilute limit.
• The model provides insights into filler dispersion and aggregation mechanisms at the molecular level.

Conclusions:

• The developed PRISM-based theory effectively models aPS melt and nanocomposite structures.
• The study elucidates the influence of nanoparticle size on aggregation in polymer melts.
• Findings offer valuable molecular-level understanding for designing tailored aPS-nanocomposite materials.