Numerical Simulation of pH-sensitive Hydrogel Response in Different Conditions
M.K. Ghantasala1 B.O. Asimba1 A. Khaminwa1 K.J. Suthar2 D.C. Mancini3
1Department of Mechanical and Aeronautical Engineering, Western Michigan University, Kalamazoo, MI, USA
2Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
3Physical Sciences and Engineering, Argonne National Laboratory, Argonne, IL, USA
The understanding of pH-sensitive hydrogel swelling response in different buffer environmental condition is essential for its use in different practical applications. This necessitates its simulation in steady state and transient conditions. This paper mainly deals with the details of the numerical simulation performed by developing coupled formulation of chemo-electro-mechanical behavior of the hydrogel in response to changing pH of the surrounding solution. Simulations were performed to determine the response of hydrogel with varying pH of the surrounding solution in a wide range of pH (2-12). The investigation of the responsiveness of the hydrogels is focused mainly on the study of effect of variation of pKa and Young’s Modulus of the gel. The methodology used for this finite element based simulation is presented. The swelling characteristics of the hydrogel obtained under steady state conditions in these investigations are compared with previous simulations using other models/methods. This analysis is carried out using COMSOL and the effects of fixed charge density, buffer solution pH and Young’s modulus on the swelling were studied in different simulations. These simulation results are compared with available experimental evidence to show the accuracy of the model.