Polyelectrolyte Assemblies on Demand*

The controlled generation of well-defined micellar assemblies from multi-component polymer systems presently is the focus of polymer science. A straightforward way to obtain polymeric aggregates is the co-assembly of polyions of opposite charges driven by the entropically favored release of counterions and strong electrostatic interactions. In presence of a low molecular weight salt micellar dynamics are facilitated resulting in restructuring toward equilibrium morphologies, in absence of salt restructuring is prevented. We present a sophisticated polyelectrolyte system containing a thermoresponsive polymer compound for the targeted creation of differently shaped assemblies under the same final conditions: In presence of salt spherical and cylindrical micelles are prepared below and above the lower critical solution temperature, respectively. Removing the salt kinetically freezes the assemblies yielding micelles of different morphologies. The transition from equilibrium to non-equilibrium structures is repeatable using the orthogonal switching scheme with temperature and salt concentration as triggers.