Computational Modeling of Microgel-Nanoparticle Mixtures

Microgels are soft, compressible, colloidal particles composed of crosslinked polymer networks that become swollen in a good solvent. The ability to change their size and internal structure in response to changes in external stimuli (e.g., temperature, pH, concentration) allows microgels to absorb and release nanoparticles or macromolecules, suiting them well to applications as “smart” particles, such as biosensors and drug delivery vehicles. Applying Monte Carlo and molecular dynamics simulation methods to coarse-grained models of mixtures of spherical microgels [1] and hard-sphere nanoparticles, we analyze (1) how nanoparticles affect the swelling/deswelling of microgels and (2) how properties of single microgels (e.g., crosslink density) and of bulk suspensions (e.g., concentration, solvent quality) affect the ability of nanoparticles to penetrate microgels. We present simulation results for the density distribution of nanoparticles inside and outside of microgels and for pair correlation functions in these highly asymmetric soft matter mixtures.

[1] M. Urich and A. R. Denton, Soft Matter 12, 9086 (2016).