基于稀土配位作用的荧光超分子形状记忆水凝胶的构筑及仿生驱动研究

As one of the most important intelligent polymeric hydrogels including the functions of sensing, actuating and response, supramolecular shape memory hydrogels have the ability to “memorize” a temporary shape, and recover to the original shape through the combination and dissociation of molecular switches via external stimuli. Compared with the studies of classic thermo-induced shape memory polymers, the researches of supramolecular shape memory hydrogels are highly lagging, it is urgent need to explore new method to fabricate supramolecular shape memory hydrogels, as well as investigate the dynamic process of shape memory performance. This project is proposed to fabricate novel polymeric hydrogels that are able to complex with lanthanide ions, the lanthanide-ligand coordination with fluorescence-emitting behavior will be applied to stabilize temporary shapes, supramolecular shape memory hydrogels with fluorescence-emitting behavior will be obtained. The relationship between the fluorescence properties and shape memory effects will be investigated, and a new approach for investigating the process and dynamics of coordination-triggered supramolecular shape memory will be explored by employing the fluorescence method. Taking the advantage of the actuating process during shape recovery, biomimetic hydrogel actuators with simultaneously shape deformation and fluorescence color-changing functions will be developed. This research will enrich the design strategy of supramolecular shape memory hydrogels, promote the understanding of the dynamic metal-coordination supramolecular shape memory process, and inspire the design and fabrication of novel intelligent polymeric materials.

超分子形状记忆水凝胶可在外界刺激下通过可逆作用的形成或解离实现不依赖于热效应的形状记忆功能，是一种集感知、反馈、驱动为一体的智能高分子材料。与广泛研究的热致形状记忆高分子相比，目前对超分子形状记忆水凝胶的研究还较为滞后，亟需相应的材料设计与微观动态机制表征的新手段。本研究拟构筑可与稀土离子配位的高分子水凝胶，采用具有荧光发射能力的稀土配位作用固定材料的临时形状，从而发展出一种构建荧光超分子形状记忆水凝胶的新方法；系统研究形状记忆过程中材料荧光性能的精细调控规律，揭示荧光信号与形状记忆能力的关联机制，探索通过荧光信号从分子尺度表征形状记忆过程；进而利用材料形状回复过程的驱动行为及荧光性能的变化，实现复杂仿生驱动与智能变色的有机结合。本研究将丰富超分子形状记忆水凝胶的种类和构建方法，有助于深入理解其形状记忆机理，也为新型智能高分子材料的设计和开发提供实验和理论基础。

超分子形状记忆水凝胶可在外界刺激下通过分子间可逆作用的形成和解离实现临时形状的固定和形变回复，在人工肌肉、软体机器人、柔性电子等新兴领域展现出广阔的应用前景并受到广泛关注。然而与经典的热致形状记忆高分子相比，目前对超分子形状记忆水凝胶的研究还较为滞后，缺乏对其形变过程的表征及应用探索。本研究将可发射荧光的稀土配位作用及刺激响应性荧光基团引入水凝胶网络，实现了水凝胶荧光强度的时空调控，研究了其荧光颜色与形变过程的关联；通过将可导电的传感层引入智能变形高分子水凝胶，实现了通过电信号实时检测和反馈水凝胶的变形行为；提出了将形状记忆和仿生驱动相结合来控制超分子形状记忆水凝胶形变过程的新方式，实现了可编程化、非接触式的变形行为；进一步利用形状记忆高分子水凝胶的形变过程，构建了可穿越迷宫的软体机器人、凝胶运载器等一系列可远程控制的变形器件；并构建了具有高做功效率的形状记忆高分子水凝胶人工肌肉，完成了模拟手臂弯曲、提起超过自身重量 115 倍的重物等大幅应变动作。此外，本项目还通过界面扩散聚合实现了水凝胶材料的定向生长和功能的修补，可在任意亲水性二维及三维基底表面生长水凝胶，并通过分子设计和聚合方式等调节水分子在水凝胶中的扩散，实现了快速形变功能。本项目的顺利完成，为发展基于超分子作用的形状记忆高分子提供了新的思路，也将推进形状记忆高分子水凝胶在人工肌肉、软体机器人等新兴领域的应用。