可同时增强驱动应力和应变的近红外光驱动液晶弹性体  

Near-infrared light-driven liquid crystalline elastomers with simultaneously enhanced actuation strain and stress

作　　者：张煜晗 宋晨捷 保金映 李昭中 王子正 肖久梅 于美娜 高延子 张兰英 兰若尘 邹呈 杨槐 Yuhan Zhang;Chenjie Song;Jinying Bao;Zhaozhong Li;Zizheng Wang;Jiumei Xiao;Meina Yu;Yanzi Gao;Lanying Zhang;Ruochen Lan;Cheng Zou;Huai Yang(Beijing Advanced Innovation Center for Materials Genome Engineering,Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China;School of Materials Science and Engineering,Peking University,Beijing 100871,China;Key Laboratory of Polymer Chemistry and Physics of Ministry of Education,Peking University,Beijing 100871,China;School of Mathematics and Physics,University of Science and Technology Beijing,Beijing 100083,China;Institute of Advanced Materials and Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education,Jiangxi Normal University,Nanchang 330022,China;Eye Institute and School of Optometry,Tianjin Medical University Eye Hospital,Tianjin 300384,China)

机构地区：[1]Beijing Advanced Innovation Center for Materials Genome Engineering,Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China [2]School of Materials Science and Engineering,Peking University,Beijing 100871,China [3]Key Laboratory of Polymer Chemistry and Physics of Ministry of Education,Peking University,Beijing 100871,China [4]School of Mathematics and Physics,University of Science and Technology Beijing,Beijing 100083,China [5]Institute of Advanced Materials and Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education,Jiangxi Normal University,Nanchang 330022,China [6]Eye Institute and School of Optometry,Tianjin Medical University Eye Hospital,Tianjin 300384,China

出　　处：《Science China Materials》2023年第12期4803-4813,共11页中国科学（材料科学）（英文版）

基　　金：supported by the National Natural Science Foundation of China(52202081,52203322 and 52073028);the Natural Science Foundation of Jiangxi Province(20232BAB204030);China Postdoctoral Science Foundation funded project(BX2021003 and 2022M720206).

摘　　要：液晶弹性体(LCEs)在先进软执行器和机器人的应用中引起了广泛关注.具有高驱动应力和驱动应变的新兴LCEs始终是实际应用的理想选择.然而,一个常识是,LCEs特定机械性能的改善必须以牺牲其他性能为代价.在本工作中,通过简单的硫醇-丙烯酸酯反应制备了LCE,随后进行光引发的自由基聚合.通过调节侧链液晶(LC)基元的含量,调控了液晶网络的交联密度,优化了LCE的驱动.侧链LC基元的引入降低了驱动温度并且提高了驱动应变,而丙烯酸酯官能化的MXene纳米片交联了LCE基体,确保了高驱动应力和光热转化.因此,本工作通过引入侧链基元和MXene纳米片作为交联剂,同时增强了LCE的驱动应力和驱动应变,克服了LCE致动器以往高温或有害紫外光驱动、物理掺杂引起的分子扰动等局限性,大大提高了整体驱动性能(驱动应力为0.773 MPa,驱动应变为45%),实现了近红外光下的可逆变形(54%).该策略可能为优化LCE执行器的性能提供一条新途径.Liquid crystalline elastomers(LCEs)have attracted considerable attention in applications involving advanced soft actuators and robots.Emerging LCEs with high actuation stresses and actuation strains are desirable for practical applications.However,it is a common sense that improvements in the specific mechanical properties of LCEs must come at the expense of other features.In this work,an LCE material was prepared by a simple thiol-acrylate reaction followed by light-initiated radical polymerization.By adjusting the content of pendant liquid crystal(LC)mesogens,the crosslinking density of the LC network was regulated,and the actuation of the LCE was optimized.Introduction of the pendant LC mesogens reduced the actuation temperature and improved the actuation strain,while the acrylate-functionalized MXene nanosheets crosslinked the LCE matrix,ensuring high actuation stress and photothermal conversion.As a result,this work simultaneously enhanced the actuation stress and actuation strain of the LCE by introducing pendant LC mesogens and MXene nanosheets as cross-linkers,which avoided the limitations of previous LCE actuators,such as actuation by high temperature or harmful ultraviolet light,and physical doping-induced molecular disturbances.This greatly improved the overall actuation performance(the actuation stress was 0.773 MPa,and the actuation strain was 45%)and realized reversible deformation(54%)under nearinfrared light.This strategy might provide a new way to optimize the capabilities of LCE actuators.

关 键 词：liquid crystalline elastomers(LCEs) actuation stress actuation strain near-infrared light actuation 

分 类 号：O753.2[理学—晶体学]