Backmapping coarse-grained polymer models under sheared nonequilibrium conditions.

Area of Science:

• Polymer Physics
• Computational Materials Science
• Molecular Dynamics

Background:

• Coarse-grained (CG) polymer models simplify complex systems but lack atomistic detail.
• Reintroducing atomistic detail (backmapping) is crucial for accurate property prediction.
• Existing backmapping methods are often limited to equilibrium conditions.

Purpose of the Study:

• To extend the backmapping technique to nonequilibrium polymer systems.
• To address challenges in backmapping CG polymer models under shear flow.
• To develop a robust protocol for accurate atomistic reconstruction of deformed polymer structures.

Main Methods:

• Developed a backmapping protocol that preserves global deformation using position restraints.
• Performed local atomistic structure optimization within these restraints.
• Iteratively applied varied restraint patterns to minimize segment isolation artifacts.
• Validated the procedure using atactic polystyrene under steady shear flow.

Main Results:

• Successfully backmapped a coarse-grained polymer model subjected to nonequilibrium shear flow.
• The proposed protocol effectively maintained the overall deformed polymer conformation.
• Artifacts like segment isolation were significantly minimized through iterative restraint application.
• Demonstrated the method's efficacy on a realistic polymer system.

Conclusions:

• The developed backmapping protocol enables accurate atomistic reconstruction of polymers under nonequilibrium shear flow.
• This advancement is critical for simulating polymer dynamics and properties in complex flow conditions.
• The method provides a reliable approach for bridging CG and atomistic simulations in nonequilibrium scenarios.