Acetone as a polar cosolvent for pyridinium-based ionic liquids

Abstract

The work reports transport and structure properties of the three pyridinium-based ionic liquids (RTILs) -N-butylpyridinium hexafluorophosphate [BPY][PF 6 ], N-butylpyridinium trifluorosulfonate [BPY][TF] and N-butylpyridinium bis(trifluoromethanesulfonyl)imide [BPY][TFSI] -in their mixtures with acetone (ACET). The ionic conductivity maximum occurs at 10 mol% RTIL, irrespective of the anion. The absolute ionic conductivity value of [BPY][TF] is higher than those of other RTILs. This is explained by a weaker cation-anion binding than that in [BPY][PF 6 ] and smaller anion size than that of [BPY][TFSI]. All the investigated RTILs are infinitely miscible with ACET, which boosts their diffusivity and conductivity. A small viscosity of ACET favors a drastic viscosity decay in the RTIL-ACET mixtures. Structure analysis (radial distribution functions, ionic clusters) of the mixtures are in line with their transport properties providing a reliable microscopic interpretation of the observed macroscopic properties. As a molecular co-solvent, ACET constitutes an interesting alternative and competitor to more intensively investigated liquids.

Insights on the mixtures of imidazolium based ionic liquids with molecular solvents

“…Ionic liquids (ILs) are formed by ions with molecular characteristics such as bulky and asymmetric structures, delocalized charge, low charge density, presence of nonpolar alkylic chains and a proposed dual ionic and organic nature, which are the reason of their low melting temperature due to their effect on microscopic level features and intermolecular interactions [1][2][3]. These characteristics determine the properties and structure of pure ILs but also have a large effect when mixing with molecular solvents (MSs) [4][5][6][7]. Intermolecular forces between ILs and MSs are largely complex [810], even with the appearance of competition effects between the involved ions and molecules [11], because of their dependence on the protic or aprotic, polar or apolar, or hydrogen bonding ability of the MSs, and show remarkable changes with mixture composition, pressure and temperature [12][13][14][15].…”

Inedible saccharides: a platform for CO2 capturing

“…TSILs suffer from a huge increase in viscosity when loaded with CO 2 due to the hydrogen bonding (H-bonding) network between the carbamate and ammonium counterparts. This could be overcome by following different strategies such as incorporating an aprotic heterocyclic anion 36 or mixing TSILs with low-viscosity solvents 37 (more reviews regarding using TSILs for capturing CO 2 can be found elsewhere 33 , 38 ).…”

Atomically precise understanding of nanofluids: nanodiamonds and carbon nanotubes in ionic liquids

“…N-Butylpyridinium tetrafluoroborate, [BPY][BF 4 ], was used as a solvent due to a fundamental interest in the pyridiniumbased ILs. [30][31][32][33][34][35][36][37] Furthermore, imidazolium-based tetrafluoroborates are widely investigated in various contexts, whereas information on the pyridinium-based tetrafluoroborates is scarce yet. A few concentrations of nanodiamonds (NDs, 42 atoms) and singlewalled (5,5) CNTs (120 atoms) in [BPY][BF 4 ] were explored.…”