Heat Capacity of Saturated and Compressed Liquid Dimethyl Ether at Temperatures from (132 to 345) K and at Pressures to 35 MPa

Abstract

Molar heat capacities at constant volume (C v ) of dimethyl ether have been measured with an adiabatic calorimeter. Temperatures range from the triple point to 345 K, and pressures up to 35 MPa. Measurements were conducted on liquid in equilibrium with its vapor and on compressed liquid samples. The samples are of high purity, as verified by chemical analysis. Calorimetric quantities are reported for the two-phase (C v (2) ), saturatedliquid (C σ or C x ′), and single-phase (C v ) molar heat capacities. Low temperature C v(2) data were employed to estimate vapor pressures for values less than 340 kPa by applying a thermodynamic relationship between the two-phase internal energy U (2) and the temperature derivatives of the vapor pressure. Vapor pressures were calculated at temperatures as low as the triple-point temperature. The principal sources of uncertainty are the temperature rise measurement and the change-of-volume work adjustment. The expanded relative uncertainty (with a coverage factor k = 2 and thus a two-standard deviation estimate) is estimated to be 0.7% for C v , 0.5% for C v (2) , and 0.7% for C σ .

Superior Metal‐Organic Framework Activation with Dimethyl Ether

“…The limitation when applying this approach to CUS MOFs is that CO 2 is too weak of a ligand to remove solvents directly bound to the metals, and therefore CUS exposure is incomplete (Figure 1a). To overcome this problem, we propose using dimethyl ether (DME) as an activation solvent because of its very low boiling point (−24 °C) which will make evacuation facile [16–19] . Moreover, the surface tension of DME (12 mN m −1 ) is much lower than commonly used activation solvents such as CH 2 Cl 2 , acetone, DMF, minimizing capillary forces during solvent removal.…”

“…To overcome this problem, we propose using dimethyl ether (DME) as an activation solvent because of its very low boiling point (−24 °C) which will make evacuation facile. [ 16 , 17 , 18 , 19 ] Moreover, the surface tension of DME (12 mN m −1 ) is much lower than commonly used activation solvents such as CH 2 Cl 2 , acetone, DMF, minimizing capillary forces during solvent removal. We propose that DME can displace solvent that is adsorbed in the pores as well as solvent coordinated to the framework.…”

Superior Metal‐Organic Framework Activation with Dimethyl Ether

“…To overcome this problem, we propose using dimethyl ether (DME) as an activation solvent because of its very low boiling point (À 24 °C) which will make evacuation facile. [16][17][18][19] Moreover, the surface tension of DME (12 mN m À 1 ) is much lower than commonly used activation solvents such as CH 2 Cl 2 , acetone, DMF, minimizing capillary forces during solvent removal. We propose that DME can displace solvent that is adsorbed in the pores as well as solvent coordinated to the framework.…”