Model development and numerical simulation of temperature-sensitive hydrogels

A novel mathematical model is developed in this study to predict the swelling behavior and phase transition of temperature-sensitive hydrogels. The presently developed multi-physics model consists of the convection–diffusion equations for ionic concentrations, the Poisson equation for electric potential, the thermodynamic equation for equilibrium swelling ratio and the mechanical equations for deformation. To solve the multi-field coupled nonlinear partial differential governing equations, a Newton iteration procedure is carried out and the steady-state responses of temperature-sensitive hydrogels are numerically simulated by meshless finite cloud method. The ionic concentrations, electric potentials interior and exterior the hydrogels as well as the swelling deformation of the hydrogels are investigated. The parameters having important influence on the swelling deformation are also discussed. The simulating results in good agreement with experimental data validate the developed multi-physics model.