Modeling oxidised polypyrrole in the condensed phase with a novel force field

Area of Science:

• Computational Materials Science
• Polymer Physics
• Condensed Matter Physics

Background:

• Simulating the condensed phases of oxidized oligopyrroles requires accurate molecular models.
• Existing models may not fully capture the thermodynamic properties of these conductive polymers.
• Developing a reliable force field is crucial for understanding material behavior.

Purpose of the Study:

• To develop a novel coarse-grained model potential for simulating oxidized oligopyrroles.
• To refine the force field parameters using in-silico simulations and experimental data.
• To achieve accurate prediction of thermodynamic properties, specifically equilibrium density.

Main Methods:

• A coarse-grained force field representing pyrrole monomers and chlorine dopants was developed.
• The model incorporates fixed charges and dipole moments for monomers and point charges for dopants.
• Parameterization involved fitting to density functional theory calculations and extensive Monte Carlo simulations.

Main Results:

• The analytic force field contains 17 adjustable parameters.
• In-silico simulations were performed on oligomers (12 monomers) with a 1:3 dopant-to-monomer ratio.
• The optimized force field achieved excellent agreement with the experimentally measured equilibrium density.

Conclusions:

• The developed coarse-grained model potential is effective for simulating oxidized oligopyrroles.
• The hybrid parametrization protocol successfully bridges theoretical calculations and experimental properties.
• This model provides a valuable tool for further research into conductive polymer systems.