ABSTRACT
Both in industry and research, a large data of substances can be manipulated, which can be systemized in order to predict and understand the systems. Accordingly, one is also interested in understanding the chemistry and the physics of liquid surfaces. It is thus important to be able to describe the interfacial forces of liquids as a function of temperature and pressure. This is most important in the case of oil recovery from reservoirs where oil is found at high temperatures and pressures. The magnitude of γ decreases almost linearly with temperature (t) (for most liquids) within a narrow range (Defay et al., 1966; Kuespert et al., 1995; Birdi, 2002, 2009):
γt = ko (1 – k1t) (2A.1)
where ko is a constant. It was found that coef†cient k1 is approximately equal to the rate of decrease of density, ρ, of liquids with rise of temperature:
ρt = ρo (1 – k1t) (2A.2)
where ρo is the value of density at t = 0 C, and the values of constant k1 are different for different liquids. Furthermore, the value of γ was related to critical temperature (TC).
