BILFF: All-Atom Force Field for Modeling Triazolium- and Benzoate-Based Ionic Liquids

Area of Science:

• Computational chemistry
• Materials science
• Physical chemistry

Background:

• Ionic liquids (ILs) are crucial for dissolving cellulose.
• Accurate molecular simulations require precise force fields.
• Previous force fields had limitations in simulating IL-cellulose interactions.

Purpose of the Study:

• To extend the BILFF (Bio-polymers in Ionic Liquids Force Field) all-atom force field.
• To accurately model three cellulose-dissolving ionic liquids: [EMTr][OAc], [EMTr][OBz], and [EMIm][OBz].
• To enable large-scale simulations of cellulose in ILs and their aqueous mixtures.

Main Methods:

• All-atom force field development and optimization.
• Quantum chemical simulations for high accuracy.
• Molecular dynamics simulations to study microstructure and properties.
• Validation against experimental density data.

Main Results:

• The extended BILFF accurately reproduces strong hydrogen bonding.
• Excellent agreement between simulations and experimental density data was achieved.
• Key phenomena like cation solvation shells and π-π stacking were modeled.
• Optimized parameters for IL-water mixtures were developed.

Conclusions:

• The enhanced BILFF force field provides high accuracy for IL simulations.
• It facilitates large-scale, reliable simulations of cellulose in ILs.
• This work is the first to offer parameters for aqueous IL mixtures, advancing cellulose processing research.