Formulations containing rheology-modifying polymers and nanometer-sized colloids have widespread use in pharmaceuticals, personal care products, and waterborne coatings. When combined in solution, the polymers temporarily “stick” to the colloids and act as bridges, forming a dynamic network with characteristic timescales spanning many orders of magnitude. Because it is computationally infeasible to capture the full range of relaxation times while maintaining atomistic resolution, we have developed a hybrid population balance-Brownian dynamics model (Pop-BD). The Pop-BD model reduces the system to pairwise colloidal interactions, with stochastic attractive contributions from polymer bridging and repulsive contributions from the layer of loops on the colloid’s surface. I will discuss how we developed the submodels that capture thepolymer-colloid interactions, and how we are using them to redesign PopBD to be more accurate, simulate experimentally relevant system sizes, and capture long timescale behavior.
Alyssa Travitz is a 5th year PhD candidate in Macromolecular Science and Engineering and Scientific Computing at the University of Michigan. She is a member of the Larson Research Group where she is developing computational models of waterborne coatings. Alyssa is also a developer for signac, an open-source data management framework, and a co-founder of the annual REACT workshop for K-12 STEM educators.