Unraveling the relationship between dielectric dynamics and electromagnetic response in the surface chemistry of CNTs

The π–π interactions in the sp 2 -C surfaces result in low electronic activity, necessitating the functionalization of CNTs to reduce surface energy and form carbon-based composites. However, current efforts to improve the electromagnetic wave absorption performance of carbon-based composites have largely focused on composite design, overlooking the changes in the intrinsic electromagnetic properties of CNTs after functionalization. Herein, three commonly used functionalized CNTs were designed and synthesized, and their kinetic processes and changes in electromagnetic wave dissipation mechanisms were systematically investigated. The results show that the functionalization of CNTs disrupts their original π-conjugated system; although dipolar polarization effects are introduced, their charge transport capability is significantly reduced, leading to a decrease in conductive losses. Furthermore, the disruption of electron transport pathways has a more pronounced impact on electromagnetic wave absorption performance, becoming a key factor influencing the overall electromagnetic wave absorption effectiveness. These findings provide important guidance for the design of novel carbon-based electromagnetic wave absorption materials. During composite design, in addition to incorporating other absorption mechanisms, particular attention should be paid to the repair of electron transport pathways to ensure excellent electromagnetic wave absorption performance.