https://doi.org/10.1351/goldbook.M03998
With respect to porous solids, the surface associated with pores communicating with the outside space may be called the @[email protected] Because the accessibility of ores may depend on the size of the fluid molecules, the extent of the @[email protected] may depend on the size of the molecules comprising the fluid, and may be different for the various components of a fluid mixture. This effect is known as the molecular sieve effect.