(742b) Molecular Dynamics Study of Choline-Based Ionic Liquids and Water Mixtures | AIChE

(742b) Molecular Dynamics Study of Choline-Based Ionic Liquids and Water Mixtures


Ma, H., Syracuse University
Tanner, E. E. L., Harvard University
Ibsen, K., Harvard University
Mitragotri, S., Harvard University
Nangia, S., Syracuse University
Choline and geranate (CAGE) based ionic liquids (ILs) have been recently developed for transdermal and oral drug delivery applications.1-3 Understanding the molecular interactions of CAGE in the presence of water is critical for its continued use in biomedical applications. Interaction of ILs and water drastically impacts the physicochemical properties of IL-water mixtures, including CAGE. We found that equimolar CAGE (1:1 choline: geranate) is hygroscopic and contained up to 20 mol% of water under atmospheric conditions. In conjunction to experimental investigation, both all-atom and coarse grain molecular dynamics simulations were performed to evaluate the physiochemical properties of 1:1 CAGE in the presence of varying amounts of water.4 Experimental and computational studies indicate that microscopic ionic interactions within CAGE are not substantially changed until the water content exceeds 65 mol%. The simulation data (radial distribution functions, density profiles, hydrogen bonding) show that geranate ions undergo a reorganization to minimize contact between the hydrophobic tails and the water molecules; evidenced by the plateau in the viscosity measurements. Our experimental and computational molecular modeling approaches provide detailed structural information of CAGE under varying hydration conditions of relevance to biomedical applications.


  1. N. Ibsen, H. Ma, A Banerjee, E. E. L. Tanner, S. Nangia, S. Mitragotri, Mechanism of antibacterial activity of choline-based ionic liquids (CAGE), ACS Biomaterials Science & Engineering 4, 2370-2379 (2018).
  2. Banerjee, K. Ibsen, T. Brown, R. Chen, C. Agatemor, and S. Mitragotri, Ionic liquids for oral insulin delivery, PNAS, 115, 7296-7301 (2018).
  3. Zakrewsky, K. S. Lovejoy, T. L. Kern, T. E. Miller, V. Le, A. Nagy, A. M. Goumas, R. S. Iyer, R. E. Del Sesto, A. T. Koppisch, D.T. Fox, and S. Mitragotri, Ionic liquids as a class of materials for transdermal delivery and pathogen neutralization, 111, 13313-13318 (2014).
  4. Eden E. L. Tanner, K. M. Piston, Ma, K. N. Ibsen, S. Nangia, S. Mitragotri, The Influence of Water on Choline-based Ionic Liquids (under review).