Mesoscopic Network Structure of a Semi‐Rigid Polyion Complex Nested in a Polycationic Hydrogel

A dual network gel, consisting of a micrometer-scaled network-like structure of a semi-rigid polyion complex nested in a nanometer-scaled polycationic network, has been developed by polymerization of a cationic monomer in the presence of a small amount of semi-rigid polyanion as dopant. Self-assembly and viscoelastic phase separation (see figure) compete with each other during the polymerization and render the micrometer-scaled network structure, which is permanently frozen by the subsequent gelation.