A comparative study of polyethylene oxide (PEO) using different coarse-graining methods

Area of Science:

• Materials Science
• Computational Chemistry
• Polymer Science

Background:

• Polyethylene oxide (PEO) is vital for battery applications due to its processability and ionic conductivity.
• Understanding PEO properties across different simulation scales is key to enhancing its performance.

Purpose of the Study:

• To comparatively analyze the molecular structure, thermodynamics, and dynamics of PEO.
• To evaluate the accuracy of three coarse-grained (CG) simulation methods against all-atom (AA) simulations.

Main Methods:

• Utilized three CG forcefields: MARTINI, SPICA, and an IBI-derived potential.
• Performed all-atom (AA) simulations using the pcff+ forcefield.
• Validated simulated densities and solubility parameters against literature data.

Main Results:

• All simulations showed good density alignment with literature; AA simulations accurately predicted solubility parameters.
• SPICA forcefield demonstrated superior accuracy in reproducing PEO's intermolecular structure (RDF), radius of gyration (Rg), and end-to-end distance (Re).
• IBI showed moderate structural accuracy, while MARTINI had limitations in representing structural properties; SPICA also yielded enhanced dynamics.

Conclusions:

• SPICA forcefield emerges as the most reliable CG method for simulating PEO's structural and dynamic properties.
• This study provides valuable insights for selecting appropriate simulation techniques to optimize PEO-based battery materials.