Comparison of coarse-grained models for cis-1,4-polyisoprene-graphite system

ABSTRACT

Structural and dynamical properties of cis-1,4-polyisoprene-graphite system were compared by four coarse-grained models. Coarse-graining of graphene layers replaced four carbon atoms by a single bead while four mapping schemes were used for the polymer. Pressure-correction was applied to the nonbonded part of the coarse-grained potential among coarse-grained polyisoprene beads. Among structural properties density profiles, bond orientation and conformation tensor as function of distance from the graphite surface were studied. Bulk values were achieved at around 2 nm from the graphite surface. Higher degree of coarse-graining showed comparatively larger fluctuations in data. Among dynamical properties mean square displacement and autocorrelation of end-to-end unit vectors for varied distances from the graphite surface were studied. Dynamics study indicated that pressure-correction method used to optimise pressure of the system resulted in slower dynamics for the higher degree of coarse-graining.

KEYWORDS:

• Molecular dynamics
• coarse-graining
• polyisoprene
• graphene
• iterative Boltzmann inversion

Acknowledgments

The authors thank PG Senapathy Centre for Computing Resource at IIT Madras for providing computational facilities.

Disclosure statement

No potential conflict of interest was reported by the author(s).