Article
Thermodynamic and conductivity properties of acetic acid — EMIMOAc ionic liquid solutions
Journal of Molecular Liquids
(2016)
Abstract
Acetic acid (HOAc) is a typical weak Brønsted acid that has been broadly used as a reactant in esterification reactions and can be used as such in ionic liquid (IL) solutions. The nature of the HOAc molecule as a solute in the IL 1-ethyl-3-methylimidazolium acetate (EMIMOAc) solutions was investigated with thermodynamic, vibrational spectroscopic, conductivity, and viscosity measurements. Calorimetry and vapor pressure-based thermodynamic measurements of the binary HOAc-EMIMOAc mixture were used to quantify the exothermic enthalpy of solution, ΔHsol, as ~ 3.2–4.9 kJ/mol. FTIR and Raman spectroscopy showed that the structures of the HOAc molecule and IL molecular ions are unchanged in the solutions relative to the pure liquids, indicating that the HOAc is a negligibly-dissociated weak acid in the IL solutions. Temperature-dependent conductivity measurements quantify the effects of the HOAc on the IL solution conductivity and confirm that the HOAc remains a mostly neutral molecular solute that interacts with the EMIMOAc IL via ion-dipole and hydrogen bond interactions.
Keywords
- Acidic ionic liquids,
- Conductivity measurements,
- Solution enthalpy,
- Vapor pressure measurements,
- Vibrational spectroscopy
Disciplines
Publication Date
April, 2016
DOI
10.1016/j.molliq.2016.01.015
Citation Information
Celina M. Renda, Yash K. Patel, Lance R. Henshaw, Kyle T. Munson, et al.. "Thermodynamic and conductivity properties of acetic acid — EMIMOAc ionic liquid solutions" Journal of Molecular Liquids Vol. 216 (2016) p. 710 - 715 ISSN: 0167-7322 Available at: http://works.bepress.com/lei-yu/1/