Temperature and Pressure Dependences of Thermophysical Properties of Some Ethylene Glycol Dimethyl Ethers from Ultrasonic Measurements

Abstract

International audienceIn this work, the speed of sound was measured in monoglyme (monoethylene glycol dimethyl ether or MEGDME) and diglyme (diethylene glycol dimethyl ether or DEGDME) in the temperature range at pressures up to 100 MPa using a pulse echo technique operating at 3 MHz; several thermophysical properties were determined in the same P-T range from these measurements. Furthermore, the density, isothermal compressibility, and isobaric thermal expansion coefficient, determined from volumetric data (direct method) and from acoustic measurements (indirect method) for four glymes have been compared. The comparison was extended to a second-order derivative of density with pressure, namely, the nonlinear acoustic parameter B/A

Study of the binary mixtures of {monoglyme+(hexane, cyclohexane, octane, dodecane)} by ECM-average and PFP models

“…[13], 0.87205 [14], 0.87221 [15], 0.87212 [16] 0.87218 [17] 7.41 7.408 [14] 298.15 0.86117 0.86120 [18], 0.86132 [13], 0.86114 [14], 0.86110 [15], 0.86150 [20], 0.86250 [16] 7.07 7.03 [19] 308.15 0.85013 0.85024 [13], 0.85006 [14], 0.84999 [15], 0.85068 [16] a Standard uncertainties u are u(T) = 0.01 K, u(q) = 2 Á 10 À5 g Á cm À3 and the combined expanded uncertainties, U c (e) = 1% with 0.95 level of confidence (k % 2). The working pressures for each compound are shown in tables 3-6. q and e values for monoglyme were reproduced (considering its experimental uncertainty) at those pressures.…”

“…The interactional parameter v 12 (required for fitting the experimental V E m values to equation (15)) was obtained by the least-squares method over the entire composition range for each system and represents the intermolecular interaction between the components of the mixtures. The values of this parameter at T = 298.15 K are listed in table 11, in addition to the equimolar values of three PFP contributions to excess molar volume.…”

“…Values of PFP interaction parameter v 12 , equimolar values of the three contributions at V E m in equation(15), and the standard deviation from the experimental excess molar volumes at T = 298.15 K.Systems v 12 /J Á cm À3FIGURE 6. Contribution of the interactions to excess molar volume on mixing, V E m; intera , against mole fraction, x, for {x alkane + (1 À x) monoglyme} at T = 298.15 K: N, hexane; Ç, octane; j, dodecane and s, cyclohexane.…”

Acoustic Nonlinearity Parameter B/A, Internal Pressure, and Acoustic Impedance Determined at Pressures up to 100 MPa for 1-Ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide

“…Especially at high pressures, the reliability, relative low uncertainty and simplicity of the speed of sound measurements make it very attractive for indirect determination of the excellent quality data on related (to speed of sound) thermodynamic and thermophysic properties which would have been difficult to obtain otherwise (Takagi, Wilhelm, 2010;Goodwin, Trusler, 2003;Dzida, 2004;Zorębski, 2014). For example, in this way extremely rare reported values of internal pressure and B/A nonlinearity parameter can be obtained (López et al, 2006;Zorębski, Zorębski, 2014).…”

“…In the case of medical applications of ultrasound, knowledge of B/A is extremely important for accurate modelling and understanding of interactions between ultrasound wave and medium (Duck, 2002;Law et al, 1985;Averkiou, Cleveland, 1999). In the case of liquids, the B/A values can be an important information's source about molecular structure (Emery et al, 1979;Sarvazyan et al, 1990;Lisnyanskii et al, 1974) as well as can be treated as a complementary parameter in the general characterization of the liquids (Lu et al, 2001;López et al, 2006). The B/A values are generally in the range of 8-12 for various classes of molecular organic liquids under atmospheric pressure and at room temperature.…”