Eco-Friendly Silver Nanoparticles/Chitosan/Poly(vinyl alcohol) Composites Exhibit Remarkable EMI Shielding Capabilities and Outstanding Thermal Conductivities

The integration and miniaturization of contemporary electronicshave led to significant challenges in dealing with electromagnetic(EM) radiation and heat accumulation. Despite these issues, achievinghigh thermal conductivity (TC) and electromagnetic interference (EMI)shielding effectiveness (SE) in polymer composite films remains anexceptionally difficult task. In this work, we used a straightforwardin situ reduction process and a vacuum-drying method to successfullyprepare a flexible Ag NPs/chitosan (CS)/PVA nanocomposite with three-dimensional(3D) conductive and thermally conductive network architectures. The3D silver pathways formed by attaching to the chitosan fibers endowthe material with simultaneous exceptional TC and EMI capabilities.At a silver concentration of 25 vol %, the TC of Ag NPs/CS/PVA nanocompositesreaches 5.18 W & BULL;m(-1)& BULL;K-1, exhibiting an approximately 25 times increase compared to CS/PVAcomposites. The electromagnetic shielding performance of 78.5 dB significantlyoutperforms the specifications of standard commercial EMI shieldingapplications by a significant margin. Additionally, Ag NPs/CS/PVAnanocomposites have greatly benefited from microwave absorption (SEA), effectively impeding the transmission of EM waves and reducingthe reflected secondary EM wave pollution. Meanwhile, the compositematerial still maintains good mechanical properties and bendability.This endeavor helped develop malleable and durable composites thatpossess superior EMI shielding capabilities and intriguing heat dissipationproperties using innovative design and fabrication methods.

Automated summary

In this study, a flexible Ag NPs/chitosan (CS)/PVA nanocomposite with three-dimensional conductive and thermally conductive network architectures was successfully prepared using a straightforward in situ reduction process and vacuum-drying method. The 3D silver pathways formed by attaching to the chitosan fibers endowed the material with simultaneous exceptional thermal conductivity and electromagnetic interference shielding effectiveness. The nanocomposite showed significantly improved thermal conductivity and electromagnetic shielding performance compared to traditional composites.