Multilayer Carbon Nanotube Film/<i>Eucommia ulmoides</i> Gum Composite Films with Excellent Electromagnetic Shielding Performance and Infrared-Triggered Shape Memory Behavior

Due to the increasing pressure of environmental protection and the depletion of oil resources, <i>Eucommia ulmoides</i> gum (EUG) as a natural renewable and degradable biopolymer has attracted more and more attention. In this work, multilayer carbon nanotube film (CNF)/EUG composite films were fabricated through the infiltration and hot-pressing process. By taking advantage of the elasticity of EUG and the specific strength of CNF, composite films exhibited much more improved mechanical strength (maximum tensile stress up to 108.4 MPa) compared with pristine EUG and CNF alone. In addition, composite films prepared with five CNF layers and five infiltration cycles of EUG solution with a thickness of 181 μm can achieve the highest total shielding effectiveness value of 88 dB in 15.6 GHz. Moreover, the folded composite film can recover quickly to the fixed permanent shape when exposed to infrared light, demonstrating fascinating infrared-triggered shape memory behavior. This work provides a facile and general method to fabricate CNF/EUG composite films and is beneficial for pushing forward the practical application of EUG materials.