Rheological tuning of MXene/latex inks for high-performance EMI shielding coatings

초록

Electrically conductive inks based on two-dimensional (2D) MXenes have attracted significant attention for highperformance electromagnetic interference (EMI) shielding. However, achieving an optimal dispersion state within latex binders remains challenging due to the complex rheological behavior of 2D fillers. Herein, we demonstrate a robust strategy for fabricating multifunctional MXene/latex conductive coatings by precisely controlling MXene dispersion through solvent dilution. Rheological analysis reveals that an optimized MXene concentration of 5 mg mL- 1 is critical for effective filler dispersion, as supported by quantitative dispersion analysis in both solution and solid states. Under these conditions, the resulting MXene/latex composites exhibit an exceptionally low electrical percolation threshold (rho c approximate to 2.12 wt%) and superior broadband EMI shielding effectiveness exceeding 60 dB across 1-40 GHz at 14 wt% MXene loading. Beyond electrical performance, the coatings demonstrate enhanced thermomechanical stiffness, strong interfacial adhesion, and flame retardancy. To evaluate practical applicability, the MXene/latex ink was applied to an EMI shielding cap for a drone flight controller, demonstrating EMI shielding performance comparable to a conventional metallic enclosure in realworld radiated emission tests (1-6 GHz). This work establishes a comprehensive processing-structure-property framework for the design of lightweight and multifunctional conductive coatings for advanced electronic applications.

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