(698d) Molecular Modeling of Ionic Liquids Confined Inside Nanoporous CMK-3 and CMK-5 Carbon Materials

Ionic liquids (ILs) have potential applications as alternative electrolytes in devices such as electrochemical double layer capacitors and dye-sensitized solar cells. In these devices, the electrodes typically consist of a nanoporous material which is in contact with the IL. However, a fundamental understanding of the behavior of ILs inside nm-sized pores is still lacking. Such knowledge is essential to optimize the performance of these IL-based devices.  

In this study we investigate the behavior of 1,3-dimethylimidazolium chloride, [dmim][Cl],  confined inside two model carbon pores, which consist of hexagonally arranged nanorods (CMK-3 material) and nanotubes (CMK-5 material) made of amorphous carbon.  We report molecular dynamics results that aim at understanding the influence of (1) pore geometry and size, (2) thickness of the CMK-5 nanotubes, and (3) pore loading, on the structural and dynamical properties of the confined IL.   The effects of pore size, geometry and loading on the density profiles, orientation of the ions, and dynamics of the ions are also evaluated and discussed, as these molecular-level properties impact the macroscopic properties (e.g., electrical capacitance and resistance) of these systems.