Dynamic light scattering study of the interface evolution in porous media

The interface evolution during the evaporation of a liquid from a saturated layer of porous medium (paper) was experimentally studied using spectral analysis of intensity fluctuations of a laser radiation scattered by the layer. The data obtained were compared with the results of modeling the irreversible growth in three-dimensional lattices. The dependences of the spectral halfwidth of intensity fluctuations on the drying time demonstrate the characteristic features of drying front evolution, which proved to be similar to those found in the modeling of irreversible growth front. A comparison of the maximal halfwidths for two different saturating liquids suggests that the motion of local interfaces during the liquid evaporation from a layer of porous medium is close to the “classical” diffusion.