Precise viscosity measurements of binary liquid mixtures of acetonitrile‐water and 1,3‐dimethyl‐2‐imidazolidinone‐water

Abstract

Viscosities of binary aqueous mixtures of Acetonitrile (AN) and 1,3-Dimethyl-2-imidazolidinone (Dimethylethyleneurea, DMEU) have been measured at atmospheric pressure and temperatures of 20, 25, 30, 35 and 40°C over the entire concentration region by means of Ubbelohde capillary viscometers, type Oc. For a set of 6 viscometers kinetic energy correction functions (Hagenbach-Couette correction) have been experimentally determined for each viscometer using tridistilled water and commercially available liquids. Further corrections accounted for buoyancy and surface tension. Viscosity measurements were carried out with at least three, usually 5 to 6 viscometers, giving viscosities with an estimated uncertainy of 0.3%. Hydrodynamic volumes were determined from relative viscosity vs. concentration curves by means of the viscosity-B-coefficient and compared to van der Waals volumes calculated using increments for functional groups from the literature. Our data indicate the formation of associated species of DMEU and water. Ber. Bunsenges. Phys. Chem. 98, 927-934 (1994) No. 7 0 VCH Verlagsgesellschaft mbH, 0-69451 Weinheim, 1994 wo5-9021/94/0707-0927 $ 10.00+.25/0

Novel highly hydrophilic zwitterionic monolithic column for hydrophilic interaction chromatography

“…where l is the linear velocity of the eluent, g is the dynamic viscosity of eluent [51,52], L is the column length and DP is the pressure drop across the column. Good linear responses between back pressure and the linear flow rate for all six solvents (figure not shown) were observed, which clearly demonstrated that the monolith was mechanically stable and capable of withstanding pressures across the column of up to 35 MPa.…”

Excess molar volumes of binary mixtures of 1,3-dimethylimidazolidin-2-one with an alkan-1-ol at the temperatures 283.15K, 298.15K, and 313.15K

“…Their V E m curves for (DMI + methanol) and (DMI + ethanol) cross at x 1 % 0.27 and 0.74 and those for (DMI + propan-1-ol) and (DMI + butan-1-ol) cross at x 1 % 0.55. Furthermore, there is no systematic variation in composition (x 1 ) min of DMI at which V E m shows a minimum for (DMI + an alkan-1-ol); (x 1 ) min % 0.45, 0.31, 0.47, and 0.53 are, respectively, obtained for binary mixtures of DMI with [9]. f The value a p was evaluated from the density data in the temperature range from 283.15 K to 313.15 K tabulated in reference [11], assuming the density q is a linear function of temperature T: q/(kg AE m À3 ) = a + b(T/K).…”

“…The densities q of pure substances determined at T = (283.15, 298.15, and 313.15) K are listed in table 1 together with those found in the literature [2,9,11,12]. Temperature dependence of densities for each substance in the temperature range between 283.15 K and 313.15 K was correlated well with the following relation of the form: The experimentally determined densities q for binary mixtures of (DMI + an alkan-1-ol) over the whole composition range at three temperatures are summarized in table 2, where the V E m values calculated from the following equation are also given:…”

“…Letcher and Deenadayalu [7,8] have studied on V E m for binary mixtures of DMI with an alkanol or an aromatic compound at 298.15 K and atmospheric pressure. Except three papers cited above, there is no other study on V E m for binary DMI mixtures; Wode and Seidel [9] have measured densities for binary aqueous DMI mixtures over the whole mole-fraction range at atmospheric pressure in the temperature range from 293.15 K to 313.15 K at intervals of 5 K only to determine the kinematic viscosities for the mixtures.…”

D2O–H2O solvent isotope effects on the volumetric properties of aqueous 1,3-dimethyl-2-imidazolidinone between (278.15 and 318.15)K

“…At the same time limited studies on thermodynamic properties of aqueous DMI have been carried out and only a few papers on this problem are available in the literature [9,14,17,[26][27][28]. In the previous works [14,17], we have determined the values of standard (at infinite dilution) molar enthalpies of DMI solution, D sol H 2 , in H 2 O and D 2 O at various temperatures.…”