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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 40: Charged Soft Matter II
CPP 40.3: Talk
Wednesday, March 18, 2015, 10:00–10:15, PC 203
Absorption of a polyelectrolyte star by an oppositely charged polyelectrolyte brush: A molecular dynamics simulation study — •Majid Farzin1,2, Torsten Kreer1, and Jens-Uwe Sommer1,2 — 1Leibniz Institute for Polymer Research Dresden — 2Technische Universitaet Dresden
By means of molecular dynamics simulations, we study interactions between a polyelectrolyte brush and an oppositely charged polyelectrolyte star. We explicitly include counter-ions of two different sizes and vary the strength of Coulomb interactions in two ways; by varying the Bjerrum length of fully charged polyelectrolytes and by choosing different charge fractions of polyelectrolyte brush monomers for a Bjerrum length corresponding to the value in water. Simulations show that there is a Bjerrum length at 10−3 (Lennard-Jones units) above which the polyelectrolyte star undergoes a discontinuous absorption transition by the polyelectrolyte brush. For a Bjerrum length of 10−2 the polyelectrolyte star has the minimum extension in the direction perpendicular to the brush. Finally, for a Bjerrum length of 0.5 the polyelectrolyte brush undergoes a collapse transition.