| Abstract
| - Using molecular dynamics simulations in combination with scaling analysis, we have studied the effects of thesolvent quality and the strength of the electrostatic interactions on the conformations of spherical polyelectrolytebrushes in salt-free solutions. The spherical polyelectrolyte brush could be in one of four conformations: (1) a star-likeconformation, (2) a “star of bundles” conformation in which the polyelectrolyte chains self-assemble into pinnedcylindrical micelles, (3) a micelle-like conformation with a dense core and charged corona, or (4) a conformation inwhich there is a thin polymeric layer uniformly covering the particle surface. These different brush conformationsappear as a result of the fine interplay between electrostatic and monomer−monomer interactions. The brush thicknessdepends nonmonotonically on the value of the Bjerrum length. This dependence of the brush thickness is due tocounterion condensation inside the brush volume. We have also established that bundle formation in poor solventconditions for the polymer backbone can also occur in a planar polyelectrolyte brush. In this case, the grafted polyelectrolytechains form hemispherical aggregates at low polymer grafting densities, cylindrical aggregates at an intermediate rangeof the grafting densities, and vertically oriented ribbon-like aggregates at high grafting densities.
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