Preparation of controllable micro-nano fiber bundle asymmetric porous PLA-PPC ethyl acetate driving film by pre-freezing treatment

Abstract

The intelligent organic solvent actuator can effectively avoid direct contact in hazardous environment, which has important research significance in the fields of soft robots, intelligent devices and sensing. The structure of organic solvent actuators usually has asymmetrical structure, but the preparation process of such structure is complex and difficult to realize. Herein, based on the wettability difference of polymers, the asymmetric porous polylactic acid (PLA)- poly propylene carbonate (PPC) driving films with micro-nano fiber bundles were prepared by the simple pre-freezing treatment. The ultra-fast reversible intelligent deformation response behavior was triggered in ethyl acetate solvent. The deformation properties, surface morphology and pore size could be adjusted by the preparation process (pre-freezing temperature and PPC content). The PLA-PPC film was prepared at −7 °C with 0.85 wt% PPC content. After being soaked in solvent for 3 s, the maximum bending degree (360°) and curvature (1.9 cm−1) were obtained. The potential application scenarios of intelligent driving materials were provided, the driving film was designed as bionic flower, artificial butterfly, gripper driver and controllable circuit switch, which proved the feasibility of driving film in practical applications.