Analysis of The Coupling Behavior of a Thin Layer of a Temperature-pH Dual Sensitive Hydrogel for an Inhomogeneous Large Deformation

Due to ionic migration and adsorption, an electrical double layer with a thickness scaled by the Debye length is formed at the hydrogel-solution interface. For a thin temperature-pH dual sensitive hydrogel whose chickness is comparable to the Debye length, its mechanical behavior may be affected by the electrical double layer. In this paper, by incorporating electromagnetic field theory into thermodynamic theory, we develop a coupled field theory for a temperature-pH dual sensitive hydrogel, and we take into account the electrical double layer. The proposed model can be used to analyze the influences of the size effect, ionic concentration, ambient temperature and solution pH value on the swelling of a thin layer of the temperature-pH sensitive hydrogel.