Fabrication of Supramolecular Fibers Having Hydrogen-bonded Main Chains and Development of Their Functions

点击翻译按钮获取中文摘要

Recently, supramolecular polymers having non-covalent main-chain backbones have been actively studied. In this study, we adopted a novel molecular design to use adjustable soft segments for protection of the rigid hydrogen-bonded main chain, which allowed hierarchical fabrication of supramolecular fibers having macro-scale alignment of the polymer chains along the fiber axis by application of external mechanical force. In the preliminary study, we successfully obtained stable and flexible supramolecular fibers from a guanosine derivative having flexible alkylsilyl side chains by melt-spinning.To test the validity and applicability of this hierarchical design for fabrication of the supramolecular fiber, flexible alkylsilyl chains were introduced to triply hydrogen-bonded supramolecular polymers of cyclohexanetriamide derivatives as the adjustable soft segment. Flexible macro-scale supramolecular fibers were also obtained by spinning, and the hydrogen-bonded linear polymer chains having … More columnar stacks of the cyclohexane core were shown to be aligned along the fiber axis. Furthermore, we found that monomer sequence of the hydrogen-bonded polymer chain could be easily controlled by bulkiness of the alkylsilyl side chains, and alternating supramolecular copolymers were obtained by simple mixing of two monomer units.To develop functional supramolecular fibers, we designed supramolecular polymers of benzenetriamide and biphenyltetraamide derivatives formed by multiple hydrogen bonds and π-staked aromatic core, and successfully fabricated them into fibers by spinning. These results confirmed that the hierarchical molecular design to use flexible alkylsilyl side chains as adjustable soft segment is effective to induce high alignment of supramolecular polymers by external mechanical force.We further demonstrated wide applicability of this molecular design for hierarchical construction of macro-scale supramolecular structures through successful fabrication of supramolecular materials such as crystals and films. Less