Wednesday, March 18, 2015 (3:15 p.m. in Yost 306)

Title: Mathematical Model of Volume Phase Transition in Polyelectrolyte Gels

Speaker: Lingxing Yao (Lecturer, Case Western Reserve University MAMS Department)

Abstract: It is well known that hydrogels are made of cross linked polymer networks that are capable of absorbing large amounts of water; they can be present in a swollen or a collapsed state. Under carefully designed physical and chemical conditions, we could observe volume phase transitions in polyelectrolyte hydrogels between those states, sometimes repeatedly. In this presentation, we will address the modeling of gel swelling/deswelling, in the context of the analysis of a hydrogel/enzyme drug delivery oscillator, by combining the theory of the elastic, electrostatic and mixing energy in a model membrane made of polyelectrolyte hydrogel. Based on these energy principles, we will propose a mathematical model system, which is capable of explaining the oscillatory volume phase transition seen in a real membrane oscillator built in engineering laboratory for the purpose of hormone drug delivery. Some detailed analysis of the model, and results of the model system compared against the experimental data will be discussed.