Transient modeling of magneto-chemo-electro-mechanical behavior of magnetic polyelectrolyte hydrogel

The transient magneto-chemo-electro-mechanical behavior is investigated by a multiphysics model for a magnetic polyelectrolyte hydrogel submerged in ionic solution with mobile ions under an external magnetic field. The model characterizes four physicochemical reactive mechanisms, namely the hydrogel magnetization, the ion polarization, the transports of solvent and ions, and the large hydrogel deformation. Moreover, the computational domain includes the hydrogel and the bath solution, where the Maxwell stresses are considered at hydrogel-surrounding interface. The model can capture the kinetics of magnetic polyelectrolyte hydrogel subject to various environmental and geometric parameters, such as the external magnetic intensity, ambient pH, salt concentration, and hydrogel-magnet distance. The simulation results reveal that a step change is found for spatial distributions of the magnetic intensity, ion concentration, as well as electric potential, if approaching hydrogel-surrounding interface. Moreover, the stronger magnetic intensity and the shorter hydrogel-magnet distance induce the larger compression of the hydrogel, while the higher pH level contributes to larger hydrogel extension. These findings may provide the guidance in design and optimization of the magnetic polyelectrolyte hydrogel and its related applications.