新型溶剂诱导变形的聚乙炔/取向碳纳米管复合材料

Deformable polymers, which have promising applications in a wide range of fields, including optoelectronic devices, actuators and sensors, have been a hot topic of multi-disciplinary studies. Although deformable polymers have been intensively explored in the past several decades, several problems are still unresolved. Prominent issues, involving slow response, random deformation and poor stability, seriously hindered their further development. In this project, aligned carbon nanotubes are introduced to responsive polymer to obtain solvent-driven deformable polymer composites with rapid response, controlled deformation direction and high stability. A new family of polyacetylene derivatives are studied as a demonstration. The main ideas are concluded as follows: the anisotropic interface formed by aligned carbon nanotubes will induce polymer chains to orient along the axis direction of carbon nanotubes; the highly-ordered structure endows the polymer with rapid conformation change thus enhance the response rate; the anisotropic structure of composite makes the composite film deform along the direction perpendicular to aligned carbon nanotubes; and the aligned carbon nanotubes are beneficial to improve the strength and thermal stability of the composite film. The responsive behavior of composites will be systematically studied including the influence of the composition and structure of polymer, the size and structure of aligned carbon nanotubes, the ratios of polymer and carbon nanotube, the preparation process and the environment conditions. We focus on elucidating the mechanism and rules of responsive properties enhanced by aligned carbon nanotubes and developing a series of solvent-driven deformable polymer composites with excellent performances.

敏感变形高分子材料因为在光电器件、驱动器、传感器等领域的重要应用前景，成为多学科交叉研究的一个热点方向。虽然敏感变形高分子已被广泛研究，但仍然存在一些不足，如响应慢、变形方向不可控、稳定性低等，严重制约其进一步发展。本项目拟通过引入宏观取向碳纳米管，获得在溶剂刺激下快速响应、变形方向可控、稳定性好的敏感变形高分子复合膜。主要以聚乙炔衍生物为模型，基本构想是：取向碳纳米管形成各向异性界面诱导高分子沿着其长度方向有序排列；高分子高度有序结构有利于其构象快速有效转变，提高响应速度；复合膜的各向异性结构控制其沿着垂直于碳纳米管长度方向可逆弯曲；引入取向碳纳米管将大幅提高复合膜的力学强度和热稳定性。将系统研究高分子组成和结构、碳纳米管尺寸和结构以及复合方式等参数对复合膜敏感性能的影响，重点揭示取向碳纳米管增强高分子变形性能的机制和规律，在此基础上发展出一类具有优异综合性能的敏感变形高分子复合材料。

本项目利用取向碳纳米管，诱导聚乙炔共轭分子链沿着碳纳米管长度方向取向，制备了在溶剂作用下可逆变形的复合材料，其变形方向可控且总是垂直于取向碳纳米管长度方向，同时碳纳米管的引入大幅提高了复合材料响应速度、力学强度和热稳定性。通过系统研究，揭示了取向碳纳米管增强高分子响应变形性能的机制和规律。进一步将该方法和机制拓展到其他高分子，发展了柔性可拉伸的电致变色复合纤维和应力变色复合纤维，为发展高性能敏感响应复合材料提供了新思路。在项目执行期间，项目负责人以通讯作者发表论文15篇（含接收），包括1篇Nature Protoc.、2篇Adv. Mater.和2篇Angew. Chem. Int. Ed.，在Nature Rev. Mater.上发表综述。出版1部英文专著（Elsevier）、在3部国际学术专著上撰写3个章节。申请中国发明专利6项，授权3项。参加9次国际国内学术会议。获得2017年上海市青年科技启明星等奖励。