Development of a coarse-grained force field model of polymeric 1-vinyl-3-ethylimidazolium tetrafluoroborate ionic liquids

A novel coarse-grained (CG) model for poly (1-vinyl-3-ethylimidazolium) tetrafluoroborate ([PVEim][BF₄]) was developed with the all-atom (AA) molecular dynamics simulations as a benchmark. In this model, the bonded and non-bonded potential parameters of CG force field were obtained by Boltzmann and iterative Boltzmann inversion, respectively. The simulation results show that the novel CG model can accurately describe the structural characteristics and reproduce the thermodynamic properties comparing with the AA force field model. The deviation of densities values between CG model and experiment was within 5% at 298 K. This work can be a useful guide to the computational for large-scale PILs systems.