Flexible, Robust, and Lightweight Multilayered Films Consisting of Alternating Poly(vinyl amine)/Nanofibrillated Cellulose and Porous Graphene Layers for Efficient Electromagnetic Interference Shielding

The next generation of advanced multifunctionalelectromagneticinterference (EMI) shielding materials is highly desired for its flexibility,ruggedness, light weight, and superior multifunctional shielding performancefeatures. In particular, multilayered films comprising low-temperaturemodified porous graphene (LPG) and alternating poly(vinyl amine)/cellulosenanofibril (PCNF) layers were produced via an effective and simplealternating vacuum filtration method. Because of the mechanical frameeffect of PCNF layers, the mechanical strength and toughness of thefilms reach 402.8 MPa and 1334.3 MJ center dot m(-3), respectively.The multiple reflection mechanism of the multilayer film enables EMIshielding effectiveness (SE) of 62.02 dB with a thickness of only0.01 mm, with a specific SE of 11927 dB center dot cm(2)center dot g(-1). The multilayered films can withstand more than 3000bending cycles while maintaining their shielding performance. Bothan increase in layer spacing and the introduction of a porous structurecan effectively improve the shielding performance. The multilayeredPCNF@LPG films also show excellent Joule heating performance.