engleski

Application of a Jump-Diffusion Model to Solid-Liquid Interfaces in Ionic Liquids

Ionic liquids possess a range of tunable properties, such as conductivity and low melting points. These properties are desirable for a broad range of applications, most prominently catalysis at solid-liquid interfaces. Ions in vicinity of these interfaces show patterned or layered adsorption. To understand particle movements in and across layers found in these systems, we employ molecular dynamics to study a confined, periodic sample system consisting of hydroxylated sapphire as well as [C2Mim]+ cations and [NTf2]− anions. Common mean-square displacement approaches inherently predict ions’ diffusion tensors as a function of location within the pattern incorrectly, as the diffusive limit can not be reached for small displacements. To resolve this problem, we apply a jump-diffusion model as proposed by Liu et al., based on introducing virtual boundaries and solving the Smoluchowski equation within these virtual slabs. We then determine the transport coefficients as a function of the distance from the sapphire.

ionic liquid ; nanoconfinement ; molecular dynamics simulations ; radial distributions ; interface-normal number density

Excellence Cluster “Engineering of Advanced Materials” at the FAU, DAAD project Multiscale Modelling of Supported Ionic Liquid Phase Catalysis (2017–2018)