Meshless modeling of pH-sensitive hydrogels subjected to coupled pH and electric field stimuli: Young modulus effects and case studies

Abstract

The effect of Young's modulus on the behavior of pH-sensitive hydrogels is studied when subjected to coupled stimuli of solution pH and externally applied electric field. The study is the first instance for coupled stimuli numerical analysis of the hydrogels, in which a multieffect-coupling pH-stimulus (MECpH) model is presented. The model considers ionic diffusion, lectric potential, and large mechanical deformation. A correlation between diffusive hydrogen ion and charge groups fixed onto the hydrogel polymeric chains by the Langmuir absorption isotherm is incorporated into the model. To validate the model, the computed results by the meshless Hermite-Cloud technique are compared well with experimental data available from the literature. Then several case studies are conducted for the swelling hydrogel immersed in buffered solution subject to applied electric voltage, especially for the Young modulus effects on the volume variations of the hydrogels. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.