Gillespie's model for the kinetics of radial spreading of a finite liquid reservoir in a thin porous substrate is corrected to properly account for the time dependence of the position of the advancing meniscus. A similarity solution for the liquid volume fraction within the substrate is obtained using power-law expressions for the dependence of the permeability and the capillary pressure on the liquid volume fraction. It is shown that the asymptotic rate of spreading at long times is independent of the initial conditions.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
- Colloid and Surface Chemistry