Abstract
We present a method to determine the effective capillary pressure and permeability of a column packed with a granular material by means of imbibition experiments using a closed column and measuring both the liquid uptake and pressure differential that develops ahead of the liquid front. The method is based on finding an intermediate range of pressure differential values, where a Washburn approximation is no longer valid but a recently obtained effective description accurately reproduces the experimental results. To determine this intermediate range of pressures we calculate the goodness of fit corresponding to both the Washburn pressure-solution, valid at short times, and the implicit pressure-solution, which includes the non-linear dependence of the pressure on the liquid uptake and is compatible with finely divided solids. Using a closed column also allow us to compare the effective capillary pressure with the maximum advancing pressure measured using Bartell's static method. We perform experiments using liquid polydimethylsiloxane, and glass beads or lactose powder. We show that an effective description of the liquid imbibition is possible and determine the corresponding capillary pressure and permeability that characterize the granular system. We observe that the heterogeneity of the system reduces the characterization range. However, it was possible to characterize lactose powder columns, where the heterogeneity leads to spontaneous bubbling and static measurements are not possible.
| Original language | American English |
|---|---|
| Article number | 129280 |
| Journal | Colloids and Surfaces A: Physicochemical and Engineering Aspects |
| Volume | 648 |
| DOIs | |
| State | Published - Sep 5 2022 |
ASJC Scopus subject areas
- Surfaces and Interfaces
- Physical and Theoretical Chemistry
- Colloid and Surface Chemistry
Keywords
- Capillary rise
- Effective capillary pressure
- Finely divided solids wettability
- Granular material
- Powder wettability
- Washburn
- Wettability