Enhancing Interface Connectivity for Multifunctional Magnetic Carbon Aerogels: An In Situ Growth Strategy of Metal‐Organic Frameworks on Cellulose Nanofibrils

Abstract

Improving interface connectivity of magnetic nanoparticles in carbon aerogels is crucial, yet challenging for assembling lightweight, elastic, high‐performance, and multifunctional carbon architectures. Here, an in situ growth strategy to achieve high dispersion of metal–organic frameworks (MOFs)‐anchored cellulose nanofibrils to enhance the interface connection quality is proposed. Followed by a facile freeze‐casting and carbonization treatment, sustainable biomimetic porous carbon aerogels with highly dispersed and closely connected MOF‐derived magnetic nano‐capsules are fabricated. Thanks to the tight interface bonding of nano‐capsule microstructure, these aerogels showcase remarkable mechanical robustness and flexibility, tunable electrical conductivity and magnetization intensity, and excellent electromagnetic wave absorption performance. Achieving a reflection loss of −70.8 dB and a broadened effective absorption bandwidth of 6.0 GHz at a filling fraction of merely 2.2 wt.%, leading to a specific reflection loss of −1450 dB mm−1, surpassing all carbon‐based aerogel absorbers so far reported. Meanwhile, the aerogel manifests high magnetic sensing sensibility and excellent thermal insulation. This work provides an extendable in situ growth strategy for synthesizing MOF‐modified cellulose nanofibril structures, thereby promoting the development of high‐value‐added multifunctional magnetic carbon aerogels for applications in electromagnetic compatibility and protection, thermal management, diversified sensing, Internet of Things devices, and aerospace.

Plasma Engineering toward Improving the Microwave-Absorbing/Shielding Feature of a Biomass-Derived Material

“…The total shielding efficiency (SE T ) is calculated by the sum of the absorption (SE A ) and reflection (SE R ) shielding efficiencies. − The shielding materials operating based on the absorption have been the hotspot, obtained by the tuned impedance matching. This phenomenon diminishes the pollution, emerging from the reflected waves from the absorber thresholds. , The plasma-engineered biowastes illustrate the moderate shielding features boosting the general applications of PS-based products. Interestingly, the pyrolyzed biomass demonstrated outstanding SE T as a result of the conductive and polarization loss as well as metamaterial, multiple reflections and scattering, and canceled waves.…”

“…This phenomenon diminishes the pollution, emerging from the reflected waves from the absorber thresholds. 52,53 The plasma-engineered biowastes illustrate the moderate shielding features boosting the general applications of PS-based products. Interestingly, the pyrolyzed biomass demonstrated outstanding SE T as a result of the conductive and polarization loss as well as metamaterial, multiple reflections and scattering, and canceled waves.…”

Conductive Composite Inks Comprised of Waterborne Polyurethane, Silver Nanosheets, and Heat-Treated MXene Nanosheets for Electromagnetic Shielding and Thermal Management

“…When magnetic waves are blocked and reflected immediately on the interface between air and the film due to the disparity in impedance. 54,55 Meanwhile, the remaining electromagnetic waves continue to transmit into the interior of the samples and are attenuated by reflection and absorption for multiple times in the thickness directions of layered MXene/AgNS nanosheets. The integration of AgNS greatly enhanced the conductivity of the network and facilitated the rapid attenuation of the incoming EMW over a brief propagation distance.…”