Dynamics of liquid imbibition through partially soluble porous sheets

Abstract

We investigate the dynamics of liquid imbibition through partially soluble porous sheets. Using a polymeric porous sheet composed of polyethylene oxide (PEO) nanofibers, we examine the imbibition of mixtures of ethylene glycol (EG) that does not dissolve PEO and water that dissolves PEO. For aqueous EG mixtures with a concentration of greater than 70 wt% that only partially dissolves a PEO nanofibrous sheet, imbibition with dissolution is markedly slower than without dissolution. By developing a mathematical model to predict the imbibition velocity, we elucidate how dissolution changes the viscosity of the invading liquid and affects the dynamics of imbibition. This study guides us to extend the classical theoretical framework for liquid imbibition through porous media to complex porous media involving dissolution. Thus, a useful background is provided for long-term drug delivery using partially soluble porous materials and for engineering processes, such as geological sequestration and exploration, and coffee percolation.