Numerical simulation of multi-physics characteristic of hydrogels in salt solutions

Numerical simulations are conducted in this paper to predict themulti-physics behavior of ionic-strength-sensitive hydrogels in aqueous saltsolutions. The main governing equations in the presently developed modelconsist of the convection-diffusion equations calculating the distributionof ionic concentrations, the Poisson equation describing the electricpotential and the thermodynamic equations computing the swellingdeformation. To solve the multi-field coupled nonlinear partial differentialgoverning equations, a Newton iteration procedure is carried out and thesteady-state responses of the hydrogels in aqueous salt solutions arenumerically simulated by meshless finite cloud method. The ionicconcentrations, electric potentials interior and exterior the hydrogels aswell as swelling deformation of the hydrogels are investigated. The majorfactors that influence the swelling behaviors of the hydrogels are alsodiscussed. The numerical results in good agreement with the experimentaldata validate the developed multi-physics model.