Modeling microgel deswelling kinetics using dissipative particle dynamics

We use mesoscale computational modeling based on dissipative particle dynamics to explore deswelling of spherical microgel in bad solvent. The microgels are modelled using the bead spring model as randomly connected polymeric chains. Microgel is initially placed in a good solvent to equilibrate. Then the solvent surrounding microgel is replaced with a bad solvent that gradually diffuses into the microgel interior replacing the good solvent and causing the microgel network to collapse. We use the computational model to explore the effect of solvent diffusion rate on the deswelling kinetics and the resultant microgel structure. We show that solvent diffusivity is an important parameter defining microgel deswelling kinetics. In particular, we find that the deswelling is slowed when the solvent diffusivity is decreased.