Fast equilibration protocol for million atom systems of highly entangled linear polyethylene chains.

Area of Science:

• Polymer Physics
• Computational Materials Science
• Soft Matter Physics

Background:

• Direct equilibration of entangled polymer melts is hindered by slow chain dynamics.
• Traditional methods like Monte Carlo-Molecular Dynamics (MC-MD) are often used.
• Soft potentials offer a promising alternative, especially for coarse-grained models.

Purpose of the Study:

• To develop and present efficient computational protocols for equilibrating entangled polymer melts.
• To compare two distinct protocols based on the information used for initial configuration generation.
• To apply these protocols to large-scale polyethylene systems.

Main Methods:

• Utilizing soft-core harmonic potentials for initial melt equilibration.
• Developing two protocols: one using basic structural parameters, another incorporating radial and dihedral distribution functions.
• Applying the protocols to a million-particle polyethylene system with 1000-bead chains.

Main Results:

• Both protocols successfully generate equilibrated and highly entangled polymer systems.
• The second protocol, utilizing more detailed distribution functions, is significantly more computationally efficient.
• The method is applicable to both monodisperse and polydisperse systems.

Conclusions:

• Soft potential-based protocols provide an effective alternative for generating equilibrium entangled polymer structures.
• The developed methods enable the simulation of large, complex polymer systems.
• This approach advances the computational study of polymer melt properties and dynamics.