Relationship between the internal pressure and cohesive energy density of a liquid nonelectrolyte. Consequences of application of Dack’s concept

Correlation and prediction of biodiesel density for extended ranges of temperature and pressure

“…Following Ivanov and Abrosimov [70], the existence of strong intermolecular interactions in a liquid substantially increases the cohesive pressure relative to the internal pressure, while the internal pressure is comparable to the cohesive pressure for liquids without such strong intermolecular interactions. Taking water and ethanol as examples at 298.15 K and atmospheric pressure, and from the thermal expansion and isothermal compressibility values mentioned before, the internal pressures are 170 MPa and 234 MPa, respectively.…”

“…The relative importance of the various molecular interactions (dispersion, polar, hydrogen bond) present in the liquid can be evaluated by comparing the internal pressure with the cohesive pressure. If the gas phase intermolecular interactions are excluded (perfect gas behavior assumed), the cohesive pressure (or cohesive energy density) p coh is given by [70] …”

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

“…Since according to a definition, P int is the change of the internal energy per mole when the liquid undergoes a very small isothermal expansion, P int is mainly affected by weak intermolecular forces (dispersive and weakly dipolar) which are strongly affected by the intermolecular distance. Simultaneously, although the strong intermolecular forces (strong dipole-dipole and hydrogen bonding) are also distance dependent they most probably do not markedly affect the internal pressure of liquid (Dack, 1975;Ivanov, Abrosimov, 2005) since very small isothermal expansion does not necessarily disrupt such intermolecular forces. Generally, however, the interpretation of the P int is difficult and an open question because the P int can be surely partially affected by the strong intermolecular forces.…”

Estimation of solubility parameter by the modified ER equation of state

“…An exact experimental value for the enthalpy of vaporization of a component leads to a reliable value of its solubility parameter. Among the different interpretations of the cohesive energy [35][36][37][38][39][40][41], one that relates this energy to the internal pressure is more convenient to apply especially for an EOS approach. The internal pressure is well defined by [19]:…”