Polymers under non-equilibrium conditions

The group is interested in developing methods for the study of properties of polymers under non-equilibrium conditions. We have investigated the formation of structures in colloid/polymer mixtures under strong flow conditions (see image below). Nonequilibrium molecular dynamics simulations have been used to investigate the influence of hydrodynamic interactions on vertical segregation (stratification) in drying mixtures of long and short polymer chains. In agreement with previous computer simulations and theoretical modeling, the short polymers stratify above the long polymers at the top of the drying film when hydrodynamic interactions between polymers are neglected. However, no stratification occurs under the same drying conditions when hydrodynamic interactions are incorporated through an explicit solvent model. We have also used a multi-scale approach which combines molecular dynamics and kinetic Monte Carlo simulations, to study a simple and scalable method for fabricating charge-stabilized polymer nanoparticles formed through a rapid solvent exchange. 

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[Image from Howard et al., https://doi.org/10.1103/PhysRevFluids.1.044203]