Abstract
In this research work, we assumed that the densities of each
component in a mixture are linearly distributed across the
interface between the coexisting vapor and liquid phases, and we
developed a linear gradient theory model for computing interfacial
tensions of mixtures, especially mixtures containing supercritical
methane, argon, nitrogen, and carbon dioxide gases at high
pressure. With this model it is unnecessary to solve the
time-consuming density profile equations of the gradient theory
model. The model has been tested on a number of mixtures at low
and high pressures. The results show excellent agreement between
the predicted and experimental IFTs at high and moderate levels of
IFTs, while the agreement is reasonably accurate in the
near-critical region as the used equations of state reveal
classical scaling behavior. To predict accurately low IFTs (sigma
<0.1 mN/m), an equation of state with proper scaling
behavior at the critical point is at least required.Key words:
linear gradient theory; interfacial tension; equation of state;
influence parameter; density profile.
Original language | English |
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Journal | Journal of Colloid and Interface Science |
Volume | 182 |
Issue number | 0443 |
Pages (from-to) | 126-132 |
ISSN | 0021-9797 |
DOIs | |
Publication status | Published - 1996 |