The hysteresis effects of fluids confined in porous media are studied by means of a new microscopic model. We consider a slitlike pore of infinite area and finite height. In contrast to the unbounded parallel-plate case, the new model allows the formation and the disappearance of curved menisci at the open ends of the pore. This effect has a profound influence on the extent of the hysteresis loops. On the other hand, we find that the presence of the menisci does not play a significant role in locating the equilibrium first-order transition in long pores. The present treatment reconciles the traditional picture of capillary condensation with the modern microscopic treatment based on the density-functional formalism.
Microscopic Model For Hysteresis and Phase-equilibria of Fluids Confined Between Parallel Plates
MARINI BETTOLO MARCONI, Umberto;
1989-01-01
Abstract
The hysteresis effects of fluids confined in porous media are studied by means of a new microscopic model. We consider a slitlike pore of infinite area and finite height. In contrast to the unbounded parallel-plate case, the new model allows the formation and the disappearance of curved menisci at the open ends of the pore. This effect has a profound influence on the extent of the hysteresis loops. On the other hand, we find that the presence of the menisci does not play a significant role in locating the equilibrium first-order transition in long pores. The present treatment reconciles the traditional picture of capillary condensation with the modern microscopic treatment based on the density-functional formalism.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
