Abstract
We have recently developed a novel type of gel called the slide-ring gel or topological gel that is different from physical and chemical gels by using the supramolecular architecture with topological characteristics. In this gel, polymer chains with bulky end groups exhibit neither covalently cross-links as in chemical gels nor attractive interactions as in physical gels but 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; this is called the pulley effect. The slide-ring material is a new cross-linking concept for the polymer network as well as a real example of a slip-link model or sliding gel, which was previously considered only theoretically. In this report, we review recent researches on progress in the cross-linking of polymeric materials together with the synthesis, structure, and mechanical properties of the slide-ring gels. This concept of the slide-ring material can be applied to not only gels but also to a wide variety of polymeric materials without solvents.
