Interfacial enthalpy

In Eq. 1, y is the free interfacial enthalpy per surface unit, Sg is the total surface of the interface, N is the number of monomeric entities changing from the solution state (1) to the condensed state (2) /xi and /X2 are the chemical potentials of the monomeric species in the initial fluid phase and in the condensed phase that is constituted thereafter. 

Free surface energy, interfacial enthalpy and Gibbs surface energy... 

In equilibrium, the interfacial region, which according to the Gibbs convention is assumed to be contracted in a volumeless dividing plane, may be considered as an independent phase. Now, as we did for bulk phases (see Equations 3.11 through 3.13), auxiliary functions of state may be defined for the interfacial phase. Thus, the interfacial enthalpy, is defined as... 

Solid-Liquid interfacial enthalpy (Berthelot principle) ... 

It should be always remembered that the global treatment of surface hydrophobi-city-hydrophilicity based on surface and interfacial enthalpies does not include the entropy effects. 

Using approximation Eq. 6.18c to express the interfacial enthalpy in terms of the apolar (LW), Lewis acid (A) and Lewis base (B) components of the surface enthalpy for the solid and immersional liquid, the final explicit form for the enthalpy... 

Some aspects of interfacial thermodynamics will now be addressed. For simplicity we will neglect anisotropy effects (except for the consideration of equilibrium shape). The free interfacial enthalpy of the interface (of area a) can be charjicterized by defining an excess parameter G, which represents the excess of over the... 

Figure 21. Correlation between the enthalpy of formation of the oxide MO and the relative value of the interfacial parameter, AX, derived from Fig. 14.

Figure 22. Correlations between the interfacial term, AX, derived from Fig. 14, and the enthalpy of formation of the oxide MO, corrected for the work to break metal-metal bonds. I, II, in mean first, second, and third periods of the periodic table of elements. From Ref. 26, updated. (From R. Guidelli, ed, Electrified Interfaces in Physics, Chemistry, and Biology, p. 252, Fig. 3. Copyright 1992 Kluwer Academic Publishers. Reproduced with permission.)...

Flow and mass transfer are influenced in many ways by the energetic conditions at the interface [26]. These conditions are described by the interfacial tension defined by the change of the free enthalpy with interfacial area. In general, interfacial tensions between liquids, and especially between liquid mixtures, cannot be calculated, but must be measured. 

Most multicomponent systems undergo phase separation because of their positive mixing enthalpies coupled with low entropy of mixing. Morphological features have been central to the study of multicomponent systems, because domain sizes, shapes, and interfacial bonding characteristics determine the mechanical properties. A proper understanding of these features often allow synergistic behavior to be developed. 

Figure 9.15. Relations in a packed continuous How air-water contactor, (a) Sketch of the tower with differential zone over which the enthalpy and material balances are made, (b) Showing equilibrium and operating lines from which the integrand 1 fths — h) can be found as a function of liquid temperature T. (c) Showing interfacial conditions as determined by the coefficient ratio km/kh when this value is large, interfacial and saturation temperatures are identical.

Key Concepts of Interfacial Properties in Food Chemistry Equation D3.5.12 G = U + PV - TS = yA + p,/j, i Equation D3.5.13 where H is the enthalpy, F the Helmholtz free energy, and G the Gibbs free energy. These basic equations can be used to derive explicit expressions for these quantities as they apply... 

Before turning to the surface enthalpy we would like to derive an important relationship between the surface entropy and the temperature dependence of the surface tension. The Helmholtz interfacial free energy is a state function. Therefore we can use the Maxwell relations and obtain directly an important equation for the surface entropy ... 

There are two common and widely used definitions of the interfacial excess enthalpy. We can argue that enthalpy is equal to the internal energy minus the total mechanical work 7A-PVa. Since in the Gibbs convention PVa = 0 we define... 

Crystal formation depends not only on the interaction energy of a particular synthon but on a wide variety of other factors, particular crystal nucleation and growth kinetics and nucleus-solution interfacial energy. Other important factors are lattice enthalpy and lattice entropy, long range interactions... 

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