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

Coarse-Grained Modeling of Ion-Containing Polymers

Ion-containing polymers have continued to be an important research focus for several decades due to their use as an electrolyte in energy storage and conversion devices. Elucidation of connections between the mesoscopic structure and multiscale dynamics of the ions and solvent remains incompletely understood. Coarse-grained modeling provides an efficient approach for exploring the structural and dynamical properties of these soft materials. The unique physicochemical properties of such polymers are of broad interest. In this review, we summarize the current development and understanding of the structure-property relationship of ion-containing polymers and provide insights into the design of such materials determined from coarse-grained modeling and simulations accompanying significant advances in experimental strategies. We specifically concentrate on three types of ion-containing polymers: proton exchange membranes (PEMs), anion exchange membranes (AEMs), and polymerized ionic liquids (polyILs). We posit that insight into the similarities and differences in these materials will lead to guidance in the rational design of high-performance novel materials with improved properties for various power source technologies.

The effect of anion on aggregation of amino acid ionic liquid: Atomistic simulation

Aggregation behavior of dodecyl betaine chloride [DB][Cl], as an amino acid ionic liquid, and dodecyl betaine N-acetyl glycinate [DB][AG], as a bio ionic liquid, in aqueous media was studied through molecular dynamics simulation. The aggregating was investigated by radial distribution function, coordination numbers, and hydrogen bond numbers. The results demonstrated the hydrogen bond between [DB]⁺ and [AG]^- that leads to aggregation. The number of hydrogen bonds of [DB][AG] is greater than [DB][Cl] and causes a decrease in the gradient of the mean square displacement, thereby the diffusion coefficient of cation, anion, and water in [DB][AG]. The results point to a stable aggregation of [DB][AG] which is in agreement with the results of root mean square deviations. The aggregation number for [DB][AG] is 50 and 44 for [DB][Cl]. Computing the radius of gyration and geometrical radius shows that the aggregation size is 23.0 Å and 26.4 Å for [DB][AG] and [DB][Cl], respectively. It was also observed that the shape of the aggregates is quasi-spherical that points to a sub-diffusive regime.