Systematic coarse-graining of ionic liquid

We develop coarse-grained force fields (CGFFs) for computationally efficient and accurate molecular simulation of imidazolium-based ionic liquids (ILs). To obtain CGFF parameters, we employ a systematic coarse-graining approach based on the relative entropy (RE) method to reproduce not only the structure but also the thermodynamic properties of the reference all-atom molecular model. Our systematic coarse-graining approach adds a constraint to the RE minimization using Lagrange Multiplier in order to reproduce thermodynamic properties such as pressure. The Boltzmann inversion technique is used to obtain the bonded interactions, and the non-bonded and long-range electrostatic interactions are obtained using the constrained relative entropy (CRE) method, developed in this thesis. The structure and pressure obtained from the coarse-grained (CG) models for different alkyl chain lengths are in agreement with the all-atom molecular dynamics simulations at different thermodynamic states. We also find that the dynamical properties, such as diffusion, of the CG model compare well with the experimental data. The methodology developed here for reproduction of thermodynamic properties and treatment of long-range Coulombic interaction is applicable to other soft-matter.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2018

Author dc:creator

• Moradzadeh, Alireza

Contributors dc:contributor

• Aluru, Narayana R.

• Coarse-Graining, Ionic Liquid, Relative Entropy, Lagrange Multiplier

Statement dc:rights

• Copyright 2018 Alireza Moradzadeh

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/100898

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/100898