Aramid nanofiber-reinforced carbon nanotubes@cobalt ferrite nanoparticles aerogel films achieve excellent electromagnetic interference shielding, photothermal and joule heating performance

Abstract

We embedded cobalt ferrite (CoFe2O4, CFO) nanoparticles on carbon nanotubes (CNTs) through oxidation and wet chemical methods to prepare CNT@CFO. Subsequently, aramid nanofiber (ANF)-reinforced aerogel films CNT@CFO/ANF were prepared by vacuum-assisted filtration and freeze-drying. CNT@CFO is evenly interspersed in the ordered ANF layers, giving the aerogel film excellent flexibility and stretchability. In electromagnetic interference shielding (EMI SE) applications, electromagnetic coupling and rich heterogeneous interfaces alleviate impedance mismatch and improve the attenuation of electromagnetic waves. The CNT@CFO/ANF film with a thickness of 30 μm exhibits an EMI SE value of 35 dB in the X-band. The absorption coefficient of CNT@CFO/ANF exceeds 0.9, which effectively reduces secondary reflection pollution compared with CNT/ANF. In photothermal conversion applications, the dual light absorption of conjugated CNTs and semiconductor CFO enables the composite film to exhibit rapid and stable photothermal heating. At AM 1.5G intensity, the stable temperature of CNT@CFO/ANF is 60.1 °C, which is higher than that of CNT/ANF. In addition, the CNT conductive network enables films to achieve rapid response, adjustable, and long-term stable joule heating capabilities. These results indicate that CNT@CFO/ANF aerogel films prepared by a simple and efficient method have great application potential in the field of multifunctional flexible devices.