Interfacial microstructure of neutral and charged polymer brushes: A density functional theory study

Area of Science:

• Statistical mechanics
• Polymer physics
• Computational chemistry

Background:

• Polymer density functional theory (PDFT) is a key tool for studying polymer brush (PB) microstructure.
• Existing PDFT models do not fully capture the impact of grafting behavior on intramolecular and intermolecular interactions.
• Discrepancies exist between PDFT predictions and simulation results for grafted PB density profiles.

Purpose of the Study:

• To develop a refined PDFT model that incorporates physical constraints of end-grafted polymer brushes.
• To accurately predict the interfacial microstructure of both neutral and charged grafted polymer brushes.
• To elucidate the influence of grafting behavior on the free energy of polymer brush systems.

Main Methods:

• Incorporation of physical constraints of end-grafted polymer brushes into excess free energy calculations within PDFT.
• Validation of the proposed PDFT against established simulation techniques.
• Analysis of the contribution of grafting behavior to the overall free energy of polymer brush systems.

Main Results:

• The enhanced PDFT accurately predicts the density distributions of neutral and weakly charged polymer brushes.
• PDFT predictions show excellent agreement with Monte Carlo and molecular dynamics simulations.
• The study quantifies the significant impact of grafting behavior on the free energy of polymer brush systems.

Conclusions:

• The developed PDFT provides a powerful and accurate theoretical framework for investigating grafted polymer brushes.
• This method enhances the understanding of interfacial microstructure in polymer brush systems.
• The findings offer a reliable theoretical tool for future research in polymer physics and materials science.