ABSTRACT
As the apolar and polar components of the free energies of interfacial interaction are additive (Fowkes, 1983; van Oss et al., Advan. Colloid Interface Sci., 1987; Langmuir, 1988):
Δ Δ ΔG G GLW AB= + [IV-1]†
and given that:
γ i iiG≡ − 1 2
Δ [II-33]
we may also state:
γ γ γi iLW iAB= + [IV-2]
The equations governing γ iLW and γ ijLW have been treated above, in Chapter II. A crucial relation is:
ΔG12LW 1LW 2LW= −2 γ γ [II-39]
It continues to be assumed by a number of authors (see Chapter XIV) that an equation of the type of eq. [II-39] is also valid for AB interactions. However, as Fowkes (1983) already pointed out a number of years ago, this is incorrect.