Related Experiment Video
Updated: Mar 6, 2026

Synthesis of Ionic Liquid Based Electrolytes, Assembly of Li-ion Batteries, and Measurements of Performance at High Temperature
Published on: December 20, 2016
Temperature effects on the viscosity and the wavelength-dependent refractive index of imidazolium-based ionic liquids
C Chiappe1, P Margari1, A Mezzetta1
1Dipartimento di Farmacia, Università di Pisa, via Bonanno 33, 56126 Pisa, Italy.
Abstract:
A systematic study on the viscosity and refractive index of 1-alkyl-3-methylimidazolium based ionic liquids (alkyl = methyl, butyl and hexyl) combined with three phosphorus containing anions, i.e. dimethylphosphate, methyl methylphosphonate and methylphosphonate, is reported. Experimental measurements account for temperature effects, while the refractive index is determined at multiple wavelengths in the visible and near infrared region. Despite the structural similarity of these anions, significant differences in the physical properties of the resulting ILs are identified, along with the clear trend of viscosity increase - and refractive index decrease - with increasing alkyl chain length on the cation. Ab initio theoretical calculations are carried out to support and rationalise the observed behaviour.
Related Concept Videos
Phase Transitions: Melting and Freezing
Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
Surface Tension, Capillary Action, and Viscosity
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
Membrane Fluidity
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is...
Membrane Fluidity
Viscosity of Fluid

