Title: Multiple Shape Manipulation of Azobenzene-Containing Polyimide by Combining Shape Memory Effect, Photofixity, and Photodeformation

Author: Xuejie Sun, Menghan Zhang, Jia Wei*, Yanlei Yu*

Journal: ACS Macro Lett., 2023, 12, 921–927

Abstract:

The integration of different shape manipulation could greatly expand the versatility and functionality of smart materials, for which the achievement of synergism of different shape control is crucial. Here, we seek to create one kind of polyimide with integrated multiple shape manipulations by constructing the chemical network bearing azobenzene as a side chain. Trifunctional cross-linkers serving as net points of the chemical network render polyimide thermal-induced shape memory effects, which enables shape transformation. Azobenzene as a photoresponsive group is employed to achieve the photofixity and reversible photodeformability. Such photosensitive behaviors are independent of molecular prealignment and remain available after thermally shaping and fixing. As a result, these noninterfering performances induced by heat and light allow us to arbitrarily combine them to meet different needs. By integrating different shape manipulations, various shape changes and functional execution are conveniently achieved. The combination of the shape memory effect with photofixity enables the setting of diverse shapes, while the merging of it with reversible deformation facilitates the construction of actuators capable of executing functions. This study provides a new approach for the preparation of multifunctional actuators and has potential applications in the field of intelligent drivers.

Fulltext Link: https://pubs.acs.org/doi/full/10.1021/acsmacrolett.3c00195

Article Express:

  This work utilizes side-chain azobenzene polyimide and trifunctional crosslinkers(TAPOB) to prepare a crosslinked network. The material exhibits the ability to manipulate multiple shapes. Trifunctional cross-linkers serving as net points of the chemical network render polyimide thermal-induced shape memory effects, which enables shape transformation, and the azobenzene groups enabling photo-induced deformation and blue light fixing for functional execution. The unique molecular structure of side-chain polyimide allows the materials to be deformed without orientation，avoiding the interference of heat treatment on photodeformation. Therefore, the above various shape manipulation methods can be combined arbitrarily to meet different needs. This advantage allows for the integration of multiple functionalities and the construction of multifunctional actuators, including a trebuchet and spiral actuator. This research provides a new approach for the preparation of multifunctional actuators and has potential applications in the field of smart actuators.