基于动态共价键的液晶弹性体可逆三维结构加工方法研究进展

Research progress in processing methods of reversible three-dimensional structures of liquid-crystalline elastomers based on dynamic covalent bonds

液晶弹性体是一类在外界刺激(如热、光、电、磁等)下能够产生宏观可逆形变的智能材料。液晶弹性体必须经过取向后才能够展现宏观可逆形变性能。动态共价键在一定的条件下可以发生可逆断裂与再生成,能够改变传统共价交联网络的拓扑结构,因此可被用于液晶弹性体的取向中。液晶弹性体可构筑具有一定形状、且在外界刺激下能够产生可逆形变的智能三维结构,在生物医药、组织工程、航空航天以及柔性机器人等多种领域具有广阔的应用前景。基于动态共价键取向法,对液晶弹性体进行三维空间取向或对液晶弹性体进行组装,有助于提高液晶弹性体可逆三维结构的复杂性,并丰富其形变模式。本文对基于动态共价键的液晶弹性体可逆三维结构的加工方法进行综述,并对该领域的挑战和机遇进行分析。

Liquid-crystalline elastomers(LCEs)are a type of smart materials that can produce macroscopic reversible deformation under external stimuli(such as heat,light,electricity,magnetism,etc.).Only LCEs that are aligned can exhibit macroscopic reversible deformation.Dynamic covalent bonds can be reversibly broken and regenerated under certain conditions,which can change the topological structure of traditional covalent cross-linked networks.Introducing dynamic covalent bonds into LCEs enables a new strategy to align the material.Liquid-crystalline elastomer reversible three-dimensional structures have certain three-dimensional shapes and can produce reversible deformation under external stimuli,which can be used in biomedicine,tissue engineering,aerospace,and flexible robots.In order to obtain liquid-crystalline elastomer reversible three-dimensional structures with more complex shapes and multiple deformation modes,the liquid-crystalline elastomers can be three-dimensionally aligned or assembled based on the orientation method of dynamic covalent bonds.This article reviews the processing methods of the liquid-crystalline elastomer reversible three-dimensional structures based on dynamic covalent bonds,and analyzes the challenges and opportunities in this field.