Segregated structures of ring polymer melts near the surface: a molecular dynamics simulation study

Area of Science:

• Polymer Physics
• Materials Science
• Computational Chemistry

Background:

• Understanding polymer behavior in confined environments is crucial for materials design.
• Ring polymers exhibit unique topological properties distinct from linear chains.
• Surface interactions significantly influence polymer structure and dynamics.

Purpose of the Study:

• To investigate and compare the structural properties of confined ring and linear polymer melts.
• To explore the influence of confinement on polymer chain conformations and local ordering.
• To determine the validity of existing polymer theories, like the Silberberg hypothesis, for confined ring polymers.

Main Methods:

• Molecular dynamics simulations were employed to model polymer melts.
• Structural properties, including polymer size, adsorption, and coordination numbers, were analyzed.
• Local and long-range structural orderings were compared between ring and linear polymers.

Main Results:

• Local structure near surfaces is similar for both ring and linear polymers.
• The Silberberg hypothesis applies to confined linear polymers but not to confined ring polymers.
• Confined ring polymers adopt segregated conformations due to topological excluded volume repulsion.

Conclusions:

• Confinement effects on ring polymers differ significantly from linear polymers.
• Topological excluded volume is a key factor governing the structure of confined ring polymers.
• Findings offer insights into biological processes like chromosome organization in nuclei.