Lattice self-consistent field calculations of ring polymer brushes

Area of Science:

• Polymer Science
• Materials Science
• Computational Chemistry

Background:

• Polymer brushes are chains grafted to a surface, influencing material properties.
• Ring polymers, lacking end groups, present unique conformational behaviors compared to linear polymers.
• Understanding compressed polymer brushes is crucial for nanotechnology and surface engineering.

Purpose of the Study:

• To systematically investigate the behavior of ring homopolymer brushes under various compression conditions using LSCF calculations.
• To compare the stretching and pressure profiles of ring brushes with their linear counterparts.
• To validate LSCF findings against existing molecular simulation data.

Main Methods:

• Lattice Self-Consistent Field (LSCF) calculations were employed for systematic simulation.
• Simulations considered uncompressed, surface-compressed, and brush-compressed ring homopolymer brushes.
• Explicit, athermal solvent conditions were maintained throughout the simulations.

Main Results:

• Ring polymer brushes are found to be slightly less stretched than equivalent linear polymer brushes.
• The observed behavior is nearly, but not completely, identical to linear brushes with adjusted chain length and grafting density.
• LSCF results align with prior molecular simulation studies, with a noted discrepancy in reported normal pressure for opposing brushes.

Conclusions:

• Ring polymer brushes exhibit distinct stretching characteristics compared to linear brushes, even under compression.
• LSCF calculations provide a reliable method for studying complex polymer brush systems.
• Further investigation may be needed to reconcile pressure differences between ring and linear brushes in opposing configurations.