Magnetic Field-Induced Aligned Graphene/Cellulose Conductive Composites for Electroluminescent Devices

Graphene is a promising reinforcement for fiber composite materials in flexible wearable applications because of its exceptional conductivity. Researchers have focused on bridging the gap between the intrinsic conductivity of graphene and the macroscopic performance of composite materials. The anisotropy of 2D nanomaterials indicates that their orientation and distribution are crucial factors in determining the macroscopic performance of thin films and bulk materials. Various technologies developed to control the formation of microstructures include electric and magnetic field methods, hot pressing, centrifugation, and freeze-drying. In this study, we prepared flexible graphene/cellulose composite film materials and used magnetic fields to regulate the orientation and distribution of graphene within cellulose paper. Results show that the grid structure of graphene arranged on the composite material produced interconnected conductive paths and reduced the graphene permeation threshold. By giving the conductive layer a higher dielectric constant, we prevented its breakdown as a conductive film. Electroluminescent devices were constructed using graphene/cellulose flexible composite materials and achieved an effective improvement in luminescence performance. Furthermore, directional luminescence was obtained through a microstructure design. This study provides a feasible path for using 2D nanomaterials in high-performance, flexible wearable devices.