Supramolecular topological polymers: Synthesis, self-assembly and functionality

Supramolecular topological polymers not only possess the dynamic and tunable characteristics of noncovalent band, but also have the unique chemical and physical properties of covalent topological polymers. Furthermore, they display fascinating features such as reversibility, adaptiveness, self-healing and stimuliresponsiveness. Hence, supramolecular topological polymers provide new ideas for the creation of new polymer species and functional materials. In this paper, we reviewed the recent and important progress of supramolecular topological polymers from the synthesis, self-assembly to function and application. The synthetic methodologies of hyperbranched, dendritic, star, brush, crosslinking and cyclic supramolecular polymers including the direct and indirect strategies, were first emphasized. The controlled self-assembly behaviors of supramolecular topological polymers were then summarized from two aspects including the internal structure parameters (such as hydrophilichydrophobic ratio, topological structure, non-covalent bond types and force strengths and external stimuliresponsiveness (such as thermal, pH, light, redox, ion, and enzyme. As a result, the above supramolecular topological polymers can easily self-assemble to form hierarchical supramolecular structures with multiple stimuli-responsiveness at different scales and dimensions, such as spherical/cylindrical micelles, vesicles, and fibers/helical tubes. On the other hand, supramolecular topological polymers can achieve specific functional properties by the introduction of functional molecules, such as chromophore groups and biological targeted molecules. Next, the potential applications of supramolecular topological polymers in the fields of biomedical, photoelectric and self-healing materials were comprehensively discussed. Finally, the key scientific issues and possible challenges in the field of supramolecular topological polymers were briefly summarized.