Darcy's law‐based model for wicking in paper‐like swelling porous media

Abstract

The wicking of liquid into a paper-like swelling porous medium made from cellulose and superabsorbent fibers was modeled using Darcy's law. The work is built on a previous study in which the Washburn equation, modified to account for swelling, was used to predict wicking in a composite of cellulose and superabsorbent fibers. In a new wicking model proposed here, Darcy's law for flow in porous media is coupled with the mass conservation equation containing an added sink or source term to account for matrix swelling and liquid absorption. The wicking-rate predicted by the new model compares well with the previous experimental data, as well as the modified Washburn equation predictions. The effectiveness of various permeability models used with the new wicking model is also investigated.

Enhanced Absorbent Products Incorporating Cellulose and Its Derivatives: A Review

“…The magnitude of viscous resistance also depends on the sizes and lengths of the passages through which the fluid needs to flow. These relationships have been captured in Darcy's law and its various refinements by subsequent investigators (Darcy 1856;Masoodi and Pillai 2010). In its simple form, Darcy's law can be expressed as in Eq.…”

“…When applying Darcy's law to predict the rate of wicking in paper, Masoodi and Pillai (2010) noted that the model tended to work best if it was assumed that the material swelled in the course of wetting in order to fully make room for the liquid. The bioresources.com Hubbe et al (2013).…”

Analysis of emulsions concentration changes during imbibition in porous sorbents

“…The capillary pressure is the main acting force of the imbibition, and it appears due to the wetting of the porous medium by a penetrating liquid, and consequent interactions of their surface energies (Zhmud et al 2000;Hamraoui and Nylander 2002;Masoodi et al 2007). There has been an ongoing interest in the imbibition process carried out by science and industry (Zhmud et al 2000;Masoodi and Pillai 2010;Cai et al 2012). The processes and mechanisms of porous media imbibition with singlephase liquids, for example, water (Hamraoui and Nylander 2002;Masoodi and Pillai 2010); deionized water and dimethyl silicone oil (Xue et al 2006); dodecane and diethyl ether (Zhmud et al 2000); and dodecane, hexadecane, and decane (Masoodi et al 2007) were investigated experimentally and described in the literature.…”

Effect of Surfactant Concentration in the Emulsions on the Process of Oleophilic Porous Structures Imbibition

“…It appears on pores walls during their wetting by a penetrating liquid, if an adhesion force of liquid molecules exceeds the force of their mutual attraction [1][2][3][4]. The imbibition is known as a phenomenon occurring in the natural environment, i.e.…”

“…mass/height change) and time [1,[5][6][7][8][9][10]; study of the relation between the characteristics of porous structure and the imbibition rate [1,[7][8][9]; and study of the effect of the penetrating liquid characteristics on this process [5,6]. Majority of the represented results has been related to the imbibition with single-phase liquids [1,2,3,[5][6][7][8][9][10], while the issues concerning multiphase liquids, viz. emulsions, still have not been fully understood and described.…”