L-histidine Terminated Bolaamphiphile: Self-assembly And Multi-component Supramolecular Polymer

L-histidine terminated Bolaamphiphile（EDHMes） was fabricated to form a series of supramolecular self-assembly systems, based on the unique interactions between the head groups with proton, metal ions, and some organic acids. The stimuli responsive properties and fabrication of ordered macroscopic metearials had also been deeply investigated.First, we developed the new multi stimuli-responsive supramolecular hydrogelation systems based on simple Bolaamphiphile（EDHMes） and cations. EDHMes can gel 8N H+（HCl or H2SO4） stably, and form metal-hydrogels only with Cu²⁺, not any other metal ions. Interestingly, these different hydrogels have completely different nanostructures. Thus, EDHMes assemble into single-wall supramolecular nanotubes with H+; while form nanofibers with single molecular thickness via binding to Cu²⁺. The EDHMes/Cu²⁺ hydrogels can be transferred into solution by adding Fe³⁺. Most importantly, the sol-gel transformation of the solution containing EDHMes/Cu²⁺/Fe³⁺shows remarkable selective multi stimuli-responsive properties. Thus, hydrogelation of EDHMes/Cu²⁺/Fe³⁺ can be triggered either by anion or cation, or redox reactions. While further found EDHMes/Cu²⁺/Fe³⁺ can be triggered by visualized discrimination of ATP from ADP and AMP through collapse of supramolecular gels. And utilizing the different properties of Cu²⁺and Fe³⁺, the gelation of EDHMes/Cu²⁺/Fe³⁺triggered by anion or cation shows excellent selectivity.Second, a kind of two-component supramolecular polymer based on the（EDHMes） and 2,2’-bipyridine-dicarboxylic acids were found to form hydrogels although neither of the single components could gel water. Depending on the structures of the dicarboxylic acids, different behaviors of the gels were observed. Interestingly, when Cu²⁺ was doped into B5D/EDHMes supramolecular polymers, changing the hydrogels into viscoelastic supramolecular polymers, which produce macroscopic supramolecular yarn via direct drawing. These results not only can help us to further understand the fundamental mechanisms of hierarchical self-assembly, but also open a new strategy for the fabrication of novel functional supramolecular polymers.