Excess Properties and Spectroscopic Studies for Binary System of Polyethylene Glycol 200 (1) + Dimethyl Sulfoxide (2) at <i>T</i> = (298.15 to 318.15) K

This work reports density and viscosity data for binary system of polyethylene glycol 200 (PEG) (1) + dimethyl sulfoxide (DMSO) (2) over the whole concentration range at <i>T</i> = (298.15, 303.15, 308.15, 313.15, and 318.15) K as a function of composition under atmospheric pressure. From experimental density and viscosity data, the excess molar volume (<i>V</i>_m^E), viscosity deviation (Δη), the excess Gibbs free energies of activation for viscous flow (Δ­(<i>G</i>*)^E), and the apparent molar volumes (<i>V</i>_φ,<i>i</i>) were calculated. The <i>V</i>_m^E, Δη, and Δ­(<i>G</i>*)^E were fitted to a Redlich–Kister equation to obtain the coefficients and to estimate the standard deviations between the experimental and calculated quantities; meanwhile, based on the kinematic viscosity data, the viscous flow thermodynamic parameters were also calculated. In addition, based on FTIR and UV–vis spectra for the binary system of PEG (1) + DMSO (2) with various concentrations, the intermolecular interaction of PEG with DMSO was discussed

Efficient SO₂ Absorptions by Four Kinds of Deep Eutectic Solvents Based on Choline Chloride

Four kinds of deep eutectic solvents (DESs) based on choline chloride (ChCl) with ethylene glycol (EG), malonic acid (MA), urea, and thiourea as hydrogen bond donors were prepared and characterized. All these DESs show good thermal stability and can be stable at 363 K, which is beneficial for the application in flue gas desulfurization. Then, SO₂ absorption capacities of these DESs were determined at different temperatures and SO₂ partial pressures. The absorption results demonstrate that ChCl–EG (1:2) and ChCl–thiourea (1:1) DESs exhibit excellent absorption performances, and the absorption capacities are 2.88 and 2.96 mol SO₂ per mol DES at 293 K and 1 atm, respectively. In addition, the SO₂ absorption and regeneration experiments were conducted. All solvents can be regenerated at 343 K with N₂ bubbling, and the absorption capacities of DESs remain without a significant loss after six absorption and desorption cycles. What’s more, the absorption mechanism of SO₂ in these DESs were investigated by IR and ¹H NMR

Solubility of Dilute SO₂ in Mixtures of <i>N</i>,<i>N</i>‑Dimethylformamide + Polyethylene Glycol 400 and the Density and Viscosity of the Mixtures

In this work, the isothermal gas–liquid equilibrium (GLE) data were measured for the system of polyethylene glycol 400 (PEG 400) + <i>N</i>,<i>N</i>-dimethylformamide (DMF) + SO₂ + N₂ at 308.15 K and 123 kPa with SO₂ partial pressures in the range of (16.8 to 115) Pa. The Henry’s law constant (<i>H</i>′) and standard Gibbs free energy change (Δ<i>G</i>) were calculated from these GLE data. Furthermore, the densities and viscosities of binary mixtures of DMF + PEG 400 were also measured over the whole concentration range at <i>T</i> = (298.15 to 313.15) K. From the experimental data, including density and viscosity values, the excess molar volumes (<i>V</i>_m^E), and viscosity deviations (Δη), the calculated results are fitted to a Redlich–Kister equation to obtain the coefficients and estimate the standard deviations between the experimental and the calculated quantities