We have recently developed a novel type of polymer network called slide–ring materials by cross–linking polyrotaxane, the supramolecular architecture with topological characteristics. In the network, polymer chains are topologically interlocked by figure–of–eight cross–links. Hence, these cross–links can pass along the polymer chains freely to equalize the tension of the threading polymer chains similarly to pulleys. The structure and physical properties of the polymeric materials are drastically different from conventional cross–linked or noncross–linked materials. For instance, the slide–ring gel membrane shows nonlinear penetration flow properties. The concept of the slide-ring materials is not limited to cross–linked gels but includes elastomer, cross-linked polymeric materials without solvent.
