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Water Sorption and Diffusivity in [C2C1im][BF4], [C4C1im][OAc], and [C4C1im][Cl]
dc.contributor.author | Rocha, M. Alejandra | |
dc.contributor.author | Shiflett, Mark B. | |
dc.date.accessioned | 2021-05-20T17:17:38Z | |
dc.date.available | 2021-05-20T17:17:38Z | |
dc.date.issued | 2019-01-07 | |
dc.identifier.citation | Rocha, M. A.; Shiflett, M. B. Water Sorption and Diffusivity in [C2C1im][BF4], [C4C1im][OAc], and[C4C1im][Cl]]. Ind. Eng. Chem. Res. 2019, 58, 1743– 1753, DOI: 10.1021/acs.iecr.8b05689 | en_US |
dc.identifier.uri | http://hdl.handle.net/1808/31637 | |
dc.description.abstract | Measurements of in situ atmospheric water absorption and desorption in ionic liquids (ILs) (1-ethyl-3-methylimidazolium tetrafluoroborate [C2C1im][BF4], 1-butyl-3-methylimidazolium acetate [C4C1im][OAc], and 1-butyl-3-methylimidazolium chloride [C4C1im][Cl]) were made using a gravimetric microbalance at temperatures ranging from 283.15 to 315.15 K and relative humidity (RH) 0–70% at 101 kPa. Solubility data were well correlated using the nonrandom two-liquid (NRTL) activity model, and time dependent concentration data were used to determine the binary diffusion coefficients using one- and two-dimensional transport models of water in the IL–water systems. The solubility of water was highest in [C4C1im][OAc] (77.5 mol %), followed by [C4C1im][Cl] (68.6 mol %), and [C2C1im][BF4] (19.5 mol %) at equivalent conditions (303.15 K and 25.00% RH). The diffusion coefficients in order of increasing relative humidity ranged from 1.3 × 10–10 to 2.8 × 10–11 m2/s for [C2C1im][BF4], from 8.8 × 10–12 to 3.9 × 10–11 m2/s for [C4C1im][OAc], and from 4.5 × 10–12 to 2.8 × 10–11 m2/s for [C4C1im][Cl]. Heats of absorption were calculated and ranged from 39 to 44 kJ/mol for [C2C1im][BF4], from 47 to 45 kJ/mol for [C4C1im][OAc], and from 55 to 45 kJ/mol for [C4C1im][Cl] with increasing water mole fraction of 0.3–0.8. The water diffusivity increases with increasing water concentration in both [C4C1im][OAc] and [C4C1im][Cl] with respect to decreasing viscosity and heats of absorption. However, the diffusivity of water in [C2C1im][BF4] decreases with increasing water concentration with respect to decreasing viscosity and increasing heats of absorption. Diffusing radius calculations using the Stokes–Einstein relationship support the hypothesis that a few water molecules through hydrogen bonding form clusters with the [OAc] and [Cl] anions, but much larger water/BF4– clusters/networks are occurring in the [C2C1im][BF4] system which increase in size with increase in water concentration. | en_US |
dc.publisher | American Chemical Society | en_US |
dc.rights | Copyright © 2019 American Chemical Society | en_US |
dc.subject | Salts | en_US |
dc.subject | Absorption | en_US |
dc.subject | Diffusion | en_US |
dc.subject | Solvents | en_US |
dc.subject | Solubility | en_US |
dc.title | Water Sorption and Diffusivity in [C2C1im][BF4], [C4C1im][OAc], and [C4C1im][Cl] | en_US |
dc.type | Article | en_US |
kusw.kuauthor | Rocha, M. Alejandra | |
kusw.kuauthor | Shiflett, Mark B. | |
kusw.kudepartment | Chemical and Petroleum Engineering | en_US |
dc.identifier.doi | 10.1021/acs.iecr.8b05689 | en_US |
dc.identifier.orcid | https://orcid.org/0000-0002-7743-6692 | en_US |
dc.identifier.orcid | https://orcid.org/0000-0002-8934-6192 | en_US |
kusw.oaversion | Scholarly/refereed, publisher version | en_US |
kusw.oapolicy | This item meets KU Open Access policy criteria. | en_US |
dc.rights.accessrights | openAccess | en_US |