Densities and Viscosities of Ionic Liquid with Organic Solvents

Abstract

The ionic liquid (IL) of 1-hexyl-3-methylimidazolium acetate is widely used in chemical and bio-chemical processes. In this work, due to the high viscosity of IL, the promising chemicals (i.e., N, N-dimethylacetamide, N, N-dimethylformamide, and dimethyl sulfoxide) were selected as the additives to lower IL viscosity. The thermophysical properties of density and viscosity for IL with solvents were measured using a digital vibrating U-tube densimeter and an Ubbelohde capillary viscometer from 303.15 to 338.15 K at atmospheric pressure (0.0967 MPa), respectively. The influences of the solvents on the thermophysical properties of ionic liquid were quantitatively studied. Furthermore, based on the measurement values, the derived properties of excess molar volumes, thermal expansion coefficient, and the energy barrier were calculated, and the results showed that the mixture composition had great impact on excess volume change and viscosity. The hard-sphere model was employed to reproduce the viscosity. The infrared spectroscopy was performed to study the chemical structure to further understand the interactions between IL and the solvents.

Synthesis and characterization of ammonium-based protic ionic liquids for carbon dioxide absorption

“…Generally, α is defined as the expansion amount of substance in reaction to a change in temperature. 28 As oppose to previous work in which α increased as temperature increased, 29 based on Table 3 , the changes of α in this study is insignificant. This indicates that the α of APILs is independent of temperature.…”

Emerging Green Techniques for the Extraction of Antioxidants from Agri-Food By-Products as Promising Ingredients for the Food Industry

“…Although their use does not cause any air pollution, to date, several used ILs have shown potential environmental risks and could pose serious threats to aquatic and terrestrial ecosystems after their release [ 136 ], also due to the numerous steps required to produce them, including a range of toxic and harmful intermediates [ 1 ]. Moreover, one of the drawbacks associated with these green solvents, in comparison with conventional solvents, is their high density and viscosity [ 137 ]. The latter can be lowered by temperature, which is an important factor in the mass transfer process [ 138 ].…”

Cellulose blends from gel extrusion and compounding with polylactic acid

“…Biodegradability and ecotoxicity can be adjusted based on the combination of cation, anion and alkyl side chain moieties 15 . From a technical point of view, high viscosity 17 is a critical processing factor, but can be effectively reduced by the use of co‐solvents 18,19 . In addition, IL are not always innocent solvents in terms of degradation reactions, especially when combined with cellulose at elevated temperatures 20 .…”

“…15 From a technical point of view, high viscosity 17 is a critical processing factor, but can be effectively reduced by the use of co-solvents. 18,19 In addition, IL are not always innocent solvents in terms of degradation reactions, especially when combined with cellulose at elevated temperatures. 20 Ionic liquids are generally several times more expensive than conventional molecular solvents, which is due to the production and especially the purification costs.…”