Modeling of active multiphase materials

Abstract

AbstractIn this contribution, material modeling and experimental investigations towards a chemically‐active multiphase material are presented. The material under consideration consists of a solid skeleton, while the pore space is filled with multiple reactive pore fluids. Here, the pore space is simultaneously filled with a pore liquid and a hydrogel made of a granulate of superabsorbent polymers (SAP). The three‐phase material is modeled within a continuum mixture theory based on the Hybrid Mixture Theory (HMT). Due to the hydrophilic character, the hydrogel is able to absorb large amounts of the pore liquid and binds it to the polymer structure. As a consequence, the saturation of free liquid in the void space decreases during the absorption, which also affects the permeability with respect to seepage flow. Since the absorption dynamics as well as the maximum water capacity of the hydrogel depend highly on external stimuli, e.g. the pore fluid chemistry, temperature, electric and magnetic fields, hydrogels are usually called active or functional materials. The hydrogel material used in this study is sensitive with respect to the ion concentration of the surrounding pore liquid.