ROMP Synthesis of Side‐Chain Ferrocene‐Containing Polyelectrolyte and Its Redox‐Responsive Hydrogels Showing Dramatically Improved Swelling with β‐Cyclodextrin

A new side-chain ferrocene (Fc)-containing polyelectrolyte has been synthesized by controlled ring-opening metathesis polymerization of a water-soluble Fc-containing norbornene-based quaternary ammonium salt, as well the corresponding covalently cross-linked hydrogel. In order to provide supramolecular hydrogels whose swelling property is largely improved host−guest interaction, hydrogel soaked into β-CD aqueous solution form β-CD@Fc hydrogel, or alternatively salt monomer first formed, then copolymerized with crosslinking agent fabricate better water absorption ability. All exhibited good redox-responsiveness swelling–shrinking behaviors chemically reversibly adjusting disassembly/assembly inclusion complexes. This example polycationic possessing properties based on splitting/combining and Fc units, potential applications are expected drug delivery actuators.