Berlin 2018 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 51: Hydrogels and Microgels

CPP 51.5: Vortrag

Mittwoch, 14. März 2018, 16:00–16:15, C 264

Combining reaction ensemble Monte-Carlo simulations with Molecular Dynamics to probe the electrophoretic mobility of weak polyelectrolytes — •David Sean and Christian Holm — Institute for Computational Physics, University of Stuttgart, Stuttgart, Germany

Monomers in strong polyacids become negatively charged due to a strong chemical drive bringing them towards a deprotonated state. In weak polyelectrolytes however, the chemical drive is weak and monomer ionization often change between its (negatively charged) dissociated state and a (neutral) associated state. The reaction ensemble Monte-Carlo (RxMC) method allows to efficiently sample configurational states of weak polyelectrolytes under chemical equilibrium in order to obtain static properties. However, this method is inappropriate probe dynamical properties like diffusion and electrophoretic mobility. In order to probe for dynamical properties, we turn to Molecular Dynamics (MD) with hydrodynamic interactions using the Lattice Boltzmann method. With the chemical equilibrium results obtained from the RxMC simulations, MD simulations are used to integrate in time the trajectories polyelectrolytes under the influence of a driving field. Static and dynamic properties of a coarse-grained microgel model in salty conditions are reported using this methodology. We report and discuss upon a surprisingly weak dependence of the mobility as a function of the total nanogel charge.