Experimental solubility of silica in nano-pores
Résumé
We used a pressure membrane extractor (Model 1020, Soil
Moisture Equipment Corp.) to study the silica content at equilibrium
with the decreasing pore sizes of amorphous silica. The principle is
to extract the aqueous solution through a sequential process from
the larger (micrometric) pores to the thinner (some nm) pores. Each
extraction step is followed by an equilibration period.
The measurements confirmed earlier observations [1,2] that the
concentration in dissolved silica decreases when the extraction
pressure increases. The direct conclusion is that the silica solubility
is pore-size dependent. These results are interpreted with the Young-
Laplace relationship, at constant silica-solution surface tension,
which means to attribute an elasto-capillary pressure to the solid.
Domaines
Planète et Univers [physics]
Origine : Accord explicite pour ce dépôt