Bacterial cellulose nanofibers-assisted construction of core-shell structured polyaniline aerogel for superior electromagnetic wave absorption.

Abstract

Due to the increasing pollution of electromagnetic waves and the vigorous development of intelligent electronic devices, there is great interest in finding high-quality electromagnetic wave absorbing materials for integrated control boxes (ICBs) that integrate various electronic components. Polyaniline (PANI) is a new type of absorbing material with great potential due to its designable structure, simple preparation process, low density and adjustable conductivity. Herein, we prepared BCNF/PANI nanoscale conductive fibers with core-shell structure by in-situ growth of PANI on the surface of bacterial cellulose nanofibers (BCNF) by oxidative polymerization and further prepared cellulose/polyaniline/polyvinyl alcohol (BCNF/PANI/PVA) composite aerogel absorbing material by a freeze-drying process. The results show that the prepared BCNF/PANI/PVA aerogel has excellent absorption performance: the minimum reflection loss is -53.19 dB at 4.16 GHz with 6.11 mm thickness, and the effective absorption bandwidth is 2.20 GHz. The influence of the macrostructure of the BCNF/PANI/PVA absorbing unit on the absorption performance was further explored through numerical simulation, and the efficient electromagnetic protection of the small ICB was finally realized with the help of the macro-optimization strategy. This achievement provides an important reference and guidance for further developing and applying high-performance electromagnetic wave absorbing materials.